--- wikisrc/guide/net-practice.mdwn 2015/06/19 19:18:31 1.5 +++ wikisrc/guide/net-practice.mdwn 2021/04/12 13:15:03 1.8 @@ -1,1572 +1,2 @@ -**Contents** - -[[!toc levels=3]] - -# Setting up TCP/IP on NetBSD in practice - -## A walk through the kernel configuration - -Before we dive into configuring various aspects of network setup, we want to -walk through the necessary bits that have to or can be present in the kernel. -See [[Compiling the kernel|guide/kernel]] for more details on compiling the -kernel, we will concentrate on the configuration of the kernel here. We will -take the i386/GENERIC config file as an example here. Config files for other -platforms should contain similar information, the comments in the config files -give additional hints. Besides the information given here, each kernel option is -also documented in the -[[!template id=man name="options" section="4"]] -manpage, and there is usually a manpage for each driver too, e.g. -[[!template id=man name="tlp" section="4"]]. - -The first line of each config file shows the version. It can be used to compare -against other versions via CVS, or when reporting bugs. - - options NTP # NTP phase/frequency locked loop - -If you want to run the Network Time Protocol (NTP), this option can be enabled -for maximum precision. If the option is not present, NTP will still work. See -[[!template id=man name="ntpd" section="8"]] for -more information. - - file-system NFS # Network File System client - -If you want to use another machine's hard disk via the Network File System -(NFS), this option is needed. The guide article about the -[[Network File System|guide/net-services#nfs]] gives more information on NFS. - - options NFSSERVER # Network File System server - -This option includes the server side of the NFS remote file sharing protocol. -Enable if you want to allow other machines to use your hard disk. The mentioned -article in the guide about [[NFS|guide/net-services#nfs]] contains more -information on NFS. - - #options GATEWAY # packet forwarding - -If you want to setup a router that forwards packets between networks or network -interfaces, setting this option is needed. It doesn't only switch on packet -forwarding, but also increases some buffers. See -[[!template id=man name="options" section="4"]] -for details. - - options INET # IP + ICMP + TCP + UDP - -This enables the TCP/IP code in the kernel. Even if you don't want/use -networking, you will still need this for machine-internal communication of -subsystems like the X Window System. See -[[!template id=man name="inet" section="4"]] for -more details. - - options INET6 # IPV6 - -If you want to use IPv6, this is your option. If you don't want IPv6, which is -part of NetBSD since the 1.5 release, you can remove/comment out that option. -See the -[[!template id=man name="inet6" section="4"]] -manpage and [[Next generation Internet protocol - -IPv6|guide/net-intro#ipv6-intro]] for more information on the next generation -Internet protocol. - - #options IPSEC # IP security - -Includes support for the IPsec protocol, including key and policy management, -authentication and compression. This option can be used without the previous -option INET6, if you just want to use IPsec with IPv4, which is possible. See -[[!template id=man name="ipsec" section="4"]] for -more information. - - #options IPSEC_ESP # IP security (encryption part; define w/IPSEC) - -This option is needed in addition to IPSEC if encryption is wanted in IPsec. - - #options MROUTING # IP multicast routing - -If multicast services like the MBone services should be routed, this option -needs to be included. Note that the routing itself is controlled by the -[[!template id=man name="mrouted" section="8"]] -daemon. - - options ISO,TPIP # OSI - #options EON # OSI tunneling over IP - -These options include the OSI protocol stack, which was said for a long time to -be the future of networking. It's mostly history these days. :-) See the -[[!template id=man name="iso" section="4"]] manpage -for more information. - - options NETATALK # AppleTalk networking protocols - -Include support for the AppleTalk protocol stack. Userland server programs are -needed to make use of that. See pkgsrc/net/netatalk and pkgsrc/net/netatalk-asun -for such packages. More information on the AppleTalk protocol and protocol stack -are available in the -[[!template id=man name="atalk" section="4"]] -manpage. - - options PPP_BSDCOMP # BSD-Compress compression support for PPP - options PPP_DEFLATE # Deflate compression support for PPP - options PPP_FILTER # Active filter support for PPP (requires bpf) - -These options tune various aspects of the Point-to-Point protocol. The first two -determine the compression algorithms used and available, while the third one -enables code to filter some packets. - - options PFIL_HOOKS # pfil(9) packet filter hooks - options IPFILTER_LOG # ipmon(8) log support - -These options enable firewalling in NetBSD, using IPFilter. See the -[[!template id=man name="ipf" section="4"]] and -[[!template id=man name="ipf" section="8"]] manpages -for more information on operation of IPFilter, and [[Configuring the - gateway/firewall|guide/net-practice#ipnat-configuring-gateway]] for a - configuration example. - - # Compatibility with 4.2BSD implementation of TCP/IP. Not recommended. - #options TCP_COMPAT_42 - -This option is only needed if you have machines on the network that still run -4.2BSD or a network stack derived from it. If you've got one or more -4.2BSD-systems on your network, you've to pay attention to set the right -broadcast-address, as 4.2BSD has a bug in its networking code, concerning the -broadcast address. This bug forces you to set all host-bits in the -broadcast-address to `0`. The `TCP_COMPAT_42` option helps you ensuring this. - - options NFS_BOOT_DHCP,NFS_BOOT_BOOTPARAM - -These options enable lookup of data via DHCP or the BOOTPARAM protocol if the -kernel is told to use a NFS root file system. See the -[[!template id=man name="diskless" section="8"]] -manpage for more information. - - # Kernel root file system and dump configuration. - config netbsd root on ? type ? - #config netbsd root on sd0a type ffs - #config netbsd root on ? type nfs - -These lines tell where the kernel looks for its root file system, and which -filesystem type it is expected to have. If you want to make a kernel that uses a -NFS root filesystem via the tlp0 interface, you can do this with - - root on tlp0 type nfs - -If a `?` is used instead of a device/type, the kernel tries to -figure one out on its own. - - # ISA serial interfaces - com0 at isa? port 0x3f8 irq 4 # Standard PC serial ports - com1 at isa? port 0x2f8 irq 3 - com2 at isa? port 0x3e8 irq 5 - -If you want to use PPP or SLIP, you will need some serial (com) interfaces. -Others with attachment on USB, PCMCIA or PUC will do as well. - - # Network Interfaces - -This rather long list contains all sorts of network drivers. Please pick the one -that matches your hardware, according to the comments. For most drivers, there's -also a manual page available, e.g. -[[!template id=man name="tlp" section="4"]], -[[!template id=man name="ne" section="4"]], etc. - - # MII/PHY support - -This section lists media independent interfaces for network cards. Pick one that -matches your hardware. If in doubt, enable them all and see what the kernel -picks. See the -[[!template id=man name="mii" section="4"]] manpage -for more information. - - # USB Ethernet adapters - aue* at uhub? port ? # ADMtek AN986 Pegasus based adapters - cue* at uhub? port ? # CATC USB-EL1201A based adapters - kue* at uhub? port ? # Kawasaki LSI KL5KUSB101B based adapters - -USB-ethernet adapters only have about 2MBit/s bandwidth, but they are very -convenient to use. Of course this needs other USB related options which we won't -cover here, as well as the necessary hardware. See the corresponding manpages -for more information. - - # network pseudo-devices - pseudo-device bpfilter 8 # Berkeley packet filter - -This pseudo-device allows sniffing packets of all sorts. It's needed for -tcpdump, but also rarpd and some other applications that need to know about -network traffic. See -[[!template id=man name="bpf" section="4"]] for more -information. - - pseudo-device ipfilter # IP filter (firewall) and NAT - -This one enables the IPFilter's packet filtering kernel interface used for -firewalling, NAT (IP Masquerading) etc. See -[[!template id=man name="ipf" section="4"]] and -[Configuring the gateway/firewall|guide/net-practice#ipnat-configuring-gateway]] -for more information. - - pseudo-device loop # network loopback - -This is the `lo0` software loopback network device which is used by some -programs these days, as well as for routing things. It should not be omitted. -See [[!template id=man name="lo" section="4"]] for -more details. - - pseudo-device ppp 2 # Point-to-Point Protocol - -If you want to use PPP either over a serial interface or ethernet (PPPoE), you -will need this option. See -[[!template id=man name="ppp" section="4"]] for -details on this interface. - - pseudo-device sl 2 # Serial Line IP - -Serial Line IP is a simple encapsulation for IP over (well :) serial lines. It -does not include negotiation of IP addresses and other options, which is the -reason that it's not in widespread use today any more. See -[[!template id=man name="sl" section="4"]]. - - pseudo-device strip 2 # Starmode Radio IP (Metricom) - -If you happen to have one of the old Metricom Ricochet packet radio wireless -network devices, use this pseudo-device to use it. See the -[[!template id=man name="strip" section="4"]] -manpage for detailed information. - - pseudo-device tun 2 # network tunneling over tty - -This network device can be used to tunnel network packets to a device file, -`/dev/tun*`. Packets routed to the tun0 interface can be read from `/dev/tun0`, -and data written to `/dev/tun0` will be sent out the tun0 network interface. -This can be used to implement e.g. QoS routing in userland. See -[[!template id=man name="tun" section="4"]] for -details. - - pseudo-device gre 2 # generic L3 over IP tunnel - -The GRE encapsulation can be used to tunnel arbitrary layer 3 packets over IP, -e.g. to implement VPNs. See -[[!template id=man name="gre" section="4"]] for more. - - pseudo-device gif 4 # IPv[46] over IPv[46] tunnel (RFC 1933) - -Using the GIF interface allows to tunnel e.g. IPv6 over IPv4, which can be used -to get IPv6 connectivity if no IPv6-capable uplink (ISP) is available. Other -mixes of operations are possible, too. See the -[[!template id=man name="gif" section="4"]] manpage -for some examples. - - #pseudo-device faith 1 # IPv[46] tcp relay translation i/f - -The faith interface captures IPv6 TCP traffic, for implementing userland -IPv6-to-IPv4 TCP relays e.g. for protocol transitions. See the -[[!template id=man name="faith" section="4"]] -manpage for more details on this device. - - #pseudo-device stf 1 # 6to4 IPv6 over IPv4 encapsulation - -This adds a network device that can be used to tunnel IPv6 over IPv4 without -setting up a configured tunnel before. The source address of outgoing packets -contains the IPv4 address, which allows routing replies back via IPv4. See the -[[!template id=man name="stf" section="4"]] manpage -and [IPv6 Connectivity & Transition via 6to4|guide/net-practice#ipv6-6to4]] for -more details. - - pseudo-device vlan # IEEE 802.1q encapsulation - -This interface provides support for IEEE 802.1Q Virtual LANs, which allows -tagging Ethernet frames with a `vlan` ID. Using properly configured switches -(that also have to support VLAN, of course), this can be used to build virtual -LANs where one set of machines doesn't see traffic from the other (broadcast and -other). The -[[!template id=man name="vlan" section="4"]] manpage -tells more about this. - -## Overview of the network configuration files - -The following is a list of the files used to configure the network. The usage of -these files, some of which have already been met the first chapters, will be -described in the following sections. - - * `/etc/hosts` -- Local hosts database file. Each line contains information - regarding a known host and contains the internet address, the host's name and - the aliases. Small networks can be configured using only the hosts file, - without a *name server*. - - * `/etc/resolv.conf` -- This file specifies how the routines which provide - access to the Internet Domain Name System should operate. Generally it - contains the addresses of the name servers. - - * `/etc/ifconfig.xxx` -- This file is used for the automatic configuration of - the network card at boot. - - * `/etc/mygate` -- Contains the IP address of the gateway. - - * `/etc/nsswitch.conf` -- Name service switch configuration file. It controls - how a process looks up various databases containing information regarding - hosts, users, groups, etc. Specifically, this file defines the order to look - up the databases. For example, the line: - - hosts: files dns - - specifies that the hosts database comes from two sources, *files* (the local - `/etc/hosts` file) and *DNS*, (the Internet Domain Name System) and that the - local files are searched before the DNS. - - It is usually not necessary to modify this file. - -## Connecting to the Internet with a modem - -There are many types of Internet connections: this section explains how to -connect to a provider using a modem over a telephone line using the PPP -protocol, a very common setup. In order to have a working connection, the -following steps must be done: - - 1. Get the necessary information from the provider. - 2. Edit the file `/etc/resolv.conf` and check `/etc/nsswitch.conf`. - 3. Create the directories `/etc/ppp` and `/etc/ppp/peers` if they don't exist. - 4. Create the connection script, the chat file and the pppd options file. - 5. Created the user-password authentication file. - -Judging from the previous list it looks like a complicated procedure that -requires a lot of work. Actually, the single steps are very easy: it's just a -matter of modifying, creating or simply checking some small text files. In the -following example it will be assumed that the modem is connected to the second -serial port `/dev/tty01` (COM2 in DOS). - -A few words on the difference between `com`, `COM` and `tty`. For NetBSD, `com` -is the name of the serial port driver (the one that is displayed by `dmesg`) and -`tty` is the name of the port. Since numbering starts at 0, `com0` is the driver -for the first serial port, named `tty00`. In the DOS world, instead, `COM1` -refers to the first serial port (usually located at 0x3f8), `COM2` to the -second, and so on. Therefore `COM1` (DOS) corresponds to `/dev/tty00` (NetBSD). - -Besides external modems connected to COM ports (using `/dev/tty0[012]` on i386, -`/dev/tty[ab]` on sparc, ...) modems on USB (`/dev/ttyU*`) and pcmcia/cardbus -(`/dev/tty0[012]`) can be used. - -### Getting the connection information - -The first thing to do is ask the provider the necessary information for the -connection, which means: - - * The phone number of the nearest POP. - * The authentication method to be used. - * The username and password for the connection. - * The IP addresses of the name servers. - -### resolv.conf and nsswitch.conf - -The `/etc/resolv.conf` file must be configured using the information supplied by -the provider, especially the addresses of the DNS. In this example the two DNS -will be `194.109.123.2` and `191.200.4.52`: - - nameserver 194.109.123.2 - nameserver 191.200.4.52 - -And now an example of the `/etc/nsswitch.conf` file: - - # /etc/nsswitch.conf - group: compat - group_compat: nis - hosts: files dns - netgroup: files [notfound=return] nis - networks: files - passwd: compat - passwd_compat: nis - shells: files - -The defaults of doing hostname lookups via `/etc/hosts` followed by the DNS -works fine and there's usually no need to modify this. - -### Creating the directories for pppd - -The directories `/etc/ppp` and `/etc/ppp/peers` will contain the configuration -files for the PPP connection. After a fresh install of NetBSD they don't exist -and must be created (chmod 700). - - # mkdir /etc/ppp - # mkdir /etc/ppp/peers - -### Connection script and chat file - -The connection script will be used as a parameter on the pppd command line; it -is located in `/etc/ppp/peers` and has usually the name of the provider. For -example, if the provider's name is BigNet and your user name for the connection -to the provider is alan, an example connection script could be: - - # /etc/ppp/peers/bignet - connect '/usr/sbin/chat -v -f /etc/ppp/peers/bignet.chat' - noauth - user alan - remotename bignet.it - -In the previous example, the script specifies a *chat file* to be used for the -connection. The options in the script are detailed in the -[[!template id=man name="pppd" section="8"]] man -page. - -### Note - -If you are experiencing connection problems, add the following two lines to the -connection script - - debug - kdebug 4 - -You will get a log of the operations performed when the system tries to connect. -See [[!template id=man name="pppd" section="8"]], -[[!template id=man name="syslog.conf" section="5"]]. - -The connection script calls the chat application to deal with the physical -connection (modem initialization, dialing, ...) The parameters to chat can be -specified inline in the connection script, but it is better to put them in a -separate file. If, for example, the telephone number of the POP to call is -`02 99999999`, an example chat script could be: - - # /etc/ppp/peers/bignet.chat - ABORT BUSY - ABORT "NO CARRIER" - ABORT "NO DIALTONE" - '' ATDT0299999999 - CONNECT '' - -*Note*: If you have problems with the chat file, you can try connecting manually -to the POP with the -[[!template id=man name="cu" section="1"]] program and -verify the exact strings that you are receiving. - -### Authentication - -During authentication each of the two systems verifies the identity of the other -system, although in practice you are not supposed to authenticate the provider, -but only to be verified by him, using one of the following methods: - - * PAP/CHAP - * login - -Most providers use a PAP/CHAP authentication. - -#### PAP/CHAP authentication - -The authentication information (speak: password) is stored in the -`/etc/ppp/pap-secrets` for PAP and in `/etc/ppp/chap-secrets` for CHAP. The -lines have the following format: - - user * password - -For example: - - alan * pZY9o - -For security reasons the `pap-secrets` and `chap-secrets` files should be owned -by root and have permissions 600. - - # chown root /etc/ppp/pap-secrets - # chown root /etc/ppp/chap-secrets - # chmod 600 /etc/ppp/pap-secrets - # chmod 600 /etc/ppp/chap-secrets - -#### Login authentication - -This type of authentication is not widely used today; if the provider uses login -authentication, user name and password must be supplied in the chat file instead -of the PAP/CHAP files, because the chat file simulates an interactive login. In -this case, set up appropriate permissions for the chat file. - -The following is an example chat file with login authentication: - - # /etc/ppp/peers/bignet.chat - ABORT BUSY - ABORT "NO CARRIER" - ABORT "NO DIALTONE" - '' ATDT0299999999 - CONNECT '' - TIMEOUT 50 - ogin: alan - ssword: pZY9o - -### pppd options - -The only thing left to do is the creation of the pppd options file, which is -`/etc/ppp/options` (chmod 644): - - /dev/tty01 - lock - crtscts - 57600 - modem - defaultroute - noipdefault - -Check the -[[!template id=man name="pppd" section="8"]] man -page for the meaning of the options. - -### Testing the modem - -Before activating the link it is a good idea to make a quick modem test, in -order to verify that the physical connection and the communication with the -modem works. For the test the -[[!template id=man name="cu" section="1"]] program can -be used, as in the following example. - - 1. Create the file `/etc/uucp/port` with the following lines: - - type modem - port modem - device /dev/tty01 - speed 115200 - - (substitute the correct device in place of `/dev/tty01`). - - 2. Write the command `cu -p modem` to start sending commands to the modem. For - example: - - # cu -p modem - Connected. - ATZ - OK - ~. - - Disconnected. - # - - In the previous example the reset command (ATZ) was sent to the modem, which - replied with OK: the communication works. To exit - [[!template id=man name="cu" section="1"]], write - `~` (tilde) followed by `.` (dot), as in the example. - -If the modem doesn't work, check that it is connected to the correct port (i.e. -you are using the right port with -[[!template id=man name="cu" section="1"]]. Cables are -a frequent cause of trouble, too. - -When you start -[[!template id=man name="cu" section="1"]] and a -message saying `Permission denied` appears, check who is the owner of the -`/dev/tty##` device, it must be "uucp". For example: - - $ ls -l /dev/tty00 - crw------- 1 uucp wheel 8, 0 Mar 22 20:39 /dev/tty00 - -If the owner is root, the following happens: - - $ ls -l /dev/tty00 - crw------- 1 root wheel 8, 0 Mar 22 20:39 /dev/tty00 - $ cu -p modem - cu: open (/dev/tty00): Permission denied - cu: All matching ports in use - -### Activating the link - -At last everything is ready to connect to the provider with the following -command: - - # pppd call bignet - -where `bignet` is the name of the already described connection script. To see -the connection messages of pppd, give the following command: - - # tail -f /var/log/messages - -To disconnect, do a `kill -HUP` of `pppd`. - - # pkill -HUP pppd - -### Using a script for connection and disconnection - -When the connection works correctly, it's time to write a couple of scripts to -avoid repeating the commands every time. These two scripts can be named, for -example, `ppp-start` and `ppp-stop`. - -`ppp-start` is used to connect to the provider: - - #!/bin/sh - MODEM=tty01 - POP=bignet - if [ -f /var/spool/lock/LCK..$MODEM ]; then - echo ppp is already running... - else - pppd call $POP - tail -f /var/log/messages - fi - -`ppp-stop` is used to close the connection: - - #!/bin/sh - MODEM=tty01 - if [ -f /var/spool/lock/LCK..$MODEM ]; then - echo -f killing pppd... - kill -HUP `cat /var/spool/lock/LCK..$MODEM` - echo done - else - echo ppp is not active - fi - -The two scripts take advantage of the fact that when pppd is active, it creates -the file `LCK..tty01` in the `/var/spool/lock` directory. This file contains the -process ID (*pid*) of the pppd process. - -The two scripts must be executable: - - # chmod u+x ppp-start ppp-stop - -### Running commands after dialin - -If you find yourself to always run the same set of commands each time you dial -in, you can put them in a script `/etc/ppp/ip-up` which will be called by -[[!template id=man name="pppd" section="8"]] after -successful dial-in. Likewise, before the connection is closed down, -`/etc/ppp/ip-down` is executed. Both scripts are expected to be executable. See -[[!template id=man name="pppd" section="8"]] for -more details. - -## Creating a small home network - -Networking is one of the main strengths of Unix and NetBSD is no exception: -networking is both powerful and easy to set up and inexpensive too, because -there is no need to buy additional software to communicate or to build a server. -[[Setting up an Internet gateway with IPNAT|guide/net-practice#ipnat]] explains -how to configure a NetBSD machine to act as a gateway for a network: with IPNAT -all the hosts of the network can reach the Internet with a single connection to -a provider made by the gateway machine. The only thing to be checked before -creating the network is to buy network cards supported by NetBSD (check the -`INSTALL.*` files for a list of supported devices). - -First, the network cards must be installed and connected to a hub, switch or -directly (see the next image for an example configuration). - -Next, check that the network cards are recognized by the kernel, studying the -output of the `dmesg` command. In the following example the kernel recognized -correctly an NE2000 clone: - - ... - ne0 at isa0 port 0x280-0x29f irq 9 - ne0: NE2000 Ethernet - ne0: Ethernet address 00:c2:dd:c1:d1:21 - ... - -If the card is not recognized by the kernel, check that it is enabled in the -kernel configuration file and then that the card's IRQ matches the one that the -kernel expects. For example, this is the isa NE2000 line in the configuration -file; the kernel expects the card to be at IRQ 9. - - ... - ne0 at isa? port 0x280 irq 9 # NE[12]000 ethernet cards - ... - -If the card's configuration is different, it will probably not be found at boot. -In this case, either change the line in the kernel configuration file and -compile a new kernel or change the card's setup (usually through a setup disk -or, for old cards, a jumper on the card). - -The following command shows the network card's current configuration: - - # ifconfig ne0 - ne0: flags=8822 mtu 1500 - address: 00:50:ba:aa:a7:7f - media: Ethernet autoselect (10baseT) - inet6 fe80::250:baff:feaa:a77f%ne0 prefixlen 64 scopeid 0x1 - -The software configuration of the network card is very easy. The IP address -192.168.1.1 is assigned to the card. - - # ifconfig ne0 inet 192.168.1.1 netmask 0xffffff00 - -Note that the networks 10.0.0.0/8 and 192.168.0.0/16 are reserved for private -networks, which is what we're setting up here. - -Repeating the previous command now gives a different result: - - # ifconfig ne0 - ne0: flags=8863 mtu 1500 - address: 00:50:ba:aa:a7:7f - media: Ethernet autoselect (10baseT) - inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255 - inet6 fe80::250:baff:feaa:a77f%ne0 prefixlen 64 scopeid 0x1 - -The output of `ifconfig` has now changed: the IP address is now printed and -there are two new flags, `UP` and `RUNNING` If the interface isn't `UP`, it will -not be used by the system to send packets. - -The host was given the IP address 192.168.1.1, which belongs to the set of -addresses reserved for internal networks which are not reachable from the -Internet. The configuration is finished and must now be tested; if there is -another active host on the network, a `ping` can be tried. For example, if -192.168.1.2 is the address of the active host: - - # ping 192.168.1.2 - PING ape (192.168.1.2): 56 data bytes - 64 bytes from 192.168.1.2: icmp_seq=0 ttl=255 time=1.286 ms - 64 bytes from 192.168.1.2: icmp_seq=1 ttl=255 time=0.649 ms - 64 bytes from 192.168.1.2: icmp_seq=2 ttl=255 time=0.681 ms - 64 bytes from 192.168.1.2: icmp_seq=3 ttl=255 time=0.656 ms - ^C - ----ape PING Statistics---- - 4 packets transmitted, 4 packets received, 0.0% packet loss - round-trip min/avg/max/stddev = 0.649/0.818/1.286/0.312 ms - -With the current setup, at the next boot it will be necessary to repeat the -configuration of the network card. In order to avoid repeating the card's -configuration at each boot, add the following lines to `/etc/rc.conf`: - - auto_ifconfig=yes - ifconfig_ne0="inet 192.168.1.1 netmask 0xffffff00" - -In this example the variable `ifconfig_ne0` was set because the network card was -recognized as *ne0* by the kernel; if you are using a different adapter, -substitute the appropriate name in place of ne0. - -At the next boot the network card will be configured automatically. - -If you have a router that is connected to the internet, you can use it as -default router, which will handle all your packets. To do so, set `defaultroute` -to the router's IP address in `/etc/rc.conf`: - - defaultroute=192.168.0.254 - -Be sure to use the default router's IP address instead of name, in case your DNS -server is beyond the default router. In that case, the DNS server couldn't be -reached to resolve the default router's hostname and vice versa, creating a -chicken-and-egg problem. - -To reach hosts on your local network, and assuming you really have very few -hosts, adjust `/etc/hosts` to contain the addresses of all the hosts belonging -to the internal network. For example: - - # - # Host Database - # This file should contain the addresses and aliases - # for local hosts that share this file. - # It is used only for "ifconfig" and other operations - # before the nameserver is started. - # - # - 127.0.0.1 localhost - ::1 localhost - # - # RFC 1918 specifies that these networks are "internal". - # 10.0.0.0 10.255.255.255 - # 172.16.0.0 172.31.255.255 - # 192.168.0.0 192.168.255.255 - - 192.168.1.1 ape.insetti.net ape - 192.168.1.2 vespa.insetti.net vespa - 192.168.1.0 insetti.net - -If you are dialed in via an Internet Service Provider, or if you have a local -Domain Name Server (DNS) running, you may want to use it to resolve hostnames to -IP addresses, possibly in addition to `/etc/hosts`, which would only know your -own hosts. To configure a machine as DNS client, you need to edit -`/etc/resolv.conf`, and enter the DNS server's address, in addition to an -optional domain name that will be appended to hosts with no domain, in order to -create a FQDN for resolving. Assuming your DNS server's IP address is -192.168.1.2 and it is setup to serve for "home.net", put the following into -`/etc/resolv.conf`: - - # /etc/resolv.conf - domain home.net - nameserver 192.168.1.2 - -The `/etc/nsswitch.conf` file should be checked as explained in the previous -[[nsswitch.conf example|guide/net-practice#rc.conf_and_nsswitch.conf]]. - -Summing up, to configure the network the following must be done: the network -adapters must be installed and physically connected. Next they must be -configured (with `ifconfig`) and, finally, the file `/etc/rc.conf` must be -modified to configure the interface and possibly default router, and -`/etc/resolv.conf` and `/etc/nsswitch.conf` should be adjusted if DNS should be -used. This type of network management is sufficient for small networks without -sophisticated needs. - -## Setting up an Internet gateway with IPNAT - -The mysterious acronym IPNAT hides the Internet Protocol Network Address -Translation, which enables the routing of an internal network (e.g. your home -network as described in the previous section) on a real network (Internet). This -means that with only one *real* IP, static or dynamic, belonging to a gateway -running IPNAT, it is possible to create simultaneous connections to the Internet -for all the hosts of the internal network. - -Some usage examples of IPNAT can be found in the subdirectory -`/usr/share/examples/ipf`: look at the files `BASIC.NAT` and `nat-setup`. - -The setup for the example described in this section is detailed in the following -figure: *host 1* can connect to the Internet calling a provider with a modem and -getting a dynamic IP address. *host 2* and *host 3* can't communicate with the -Internet with a normal setup: IPNAT allows them to do it: host 1 will act as a -Internet gateway for hosts 2 and 3. Using host 1 as default router, hosts 2 and -3 will be able to access the Internet. - -![Network with gateway](/guide/images/net1.gif) -**Network with gateway** - -### Configuring the gateway/firewall - -To use IPNAT, the *pseudo-device ipfilter* must be compiled into the kernel, and -IP packet forwarding must be enabled in the kernel. To check, run: - - # sysctl net.inet.ip.forwarding - net.inet.ip.forwarding = 1 - -If the result is `1` as in the previous example, the option is enabled, -otherwise, if the result is `0` the option is disabled. You can do two things: - - 1. Compile a new kernel, with the GATEWAY option enabled. - - 2. Enable the option in the current kernel with the following command: - - # sysctl -w net.inet.ip.forwarding=1 - - You can add sysctl settings to `/etc/sysctl.conf` to have them set - automatically at boot. In this case you would want to add - - net.inet.ip.forwarding=1 - - -The rest of this section explains how to create an IPNAT configuration that is -automatically started every time that a connection to the provider is activated -with the PPP link. With this configuration all the host of a home network (for -example) will be able to connect to the Internet through the gateway machine, -even if they don't use NetBSD. - -For the setup, first, create the `/etc/ipnat.conf` file containing the following -rules: - - map ppp0 192.168.1.0/24 -> 0/32 proxy port ftp ftp/tcp - map ppp0 192.168.1.0/24 -> 0/32 portmap tcp/udp 40000:60000 - map ppp0 192.168.1.0/24 -> 0/32 - -192.168.1.0/24 are the network addresses that should be mapped. The first line -of the configuration file is optional: it enables active FTP to work through the -gateway. The second line is used to handle correctly tcp and udp packets; the -portmapping is necessary because of the many to one relationship). The third -line is used to enable ICMP, ping, etc. - -Next, create the `/etc/ppp/ip-up` file; it will be called automatically every -time that the PPP link is activated: - - #!/bin/sh - # /etc/ppp/ip-up - /etc/rc.d/ipnat forcestart - -Create the file `/etc/ppp/ip-down`; it will be called automatically when the PPP -link is closed: - - #!/bin/sh - # /etc/ppp/ip-down - /etc/rc.d/ipnat forcestop - -Both `ip-up` and `ip-down` must be executable: - - # chmod u+x ip-up ip-down - -The gateway machine is now ready. - -### Configuring the clients - -Create a `/etc/resolv.conf` file like the one on the gateway machine, to make -the clients access the same DNS server as the gateway. - -Next, make all clients use the gateway as their default router. Use the -following command: - - # route add default 192.168.1.1 - -192.168.1.1 is the address of the gateway machine configured in the previous -section. - -Of course you don't want to give this command every time, so it's better to -define the `defaultroute` entry in the `/etc/rc.conf` file: the default route -will be set automatically during system initialization, using the defaultroute -option as an argument to the `route add default` command. - -If the client machine is not using NetBSD, the configuration will be different. -On Windows PCs you need to set the gateway property of the TCP/IP protocol to -the IP address of the NetBSD gateway. - -That's all that needs to be done on the client machines. - -### Some useful commands - -The following commands can be useful for diagnosing problems: - - * `ping` -- tries to connect to other computers via ICMP (usually used for - testing if a connection exists). - * `netstat -r` -- Displays the routing tables (similar to `route show`). - * `traceroute` -- On the client it shows the route followed by the packets to - their destination. - * `tcpdump` -- Use on the gateway to monitor TCP/IP traffic. - -## Setting up a network bridge device - -A bridge can be used to combine different physical networks into one logical -network, i.e. connect them at layer 2 of the ISO-OSI model, not at layer 3, -which is what a router would do. The NetBSD `bridge` driver provides bridge -functionality on NetBSD systems. - -### Bridge example - -In this example two physical networks are going to be combined in one logical -network, 192.168.1.0, using a NetBSD bridge. The NetBSD machine which is going -to act as bridge has two interfaces, ne0 and ne1, which are each connected to -one physical network. - -The first step is to make sure support for the `bridge` is compiled in the -running kernel. Support is included in the GENERIC kernel. - -When the system is ready the bridge can be created, this can be done using the -[[!template id=man name="brconfig" section="8"]] -command. First of a bridge interface has to be created. With the following -`ifconfig` command the `bridge0` interface will be created: - - $ ifconfig bridge0 create - -Please make sure that at this point both the ne0 and ne1 interfaces are up. The -next step is to add the ne0 and ne1 interfaces to the bridge. - - $ brconfig bridge0 add ne0 add ne1 up - -This configuration can be automatically set up by creating an -`/etc/ifconfig.interface` file, in this case `/etc/ifconfig.bridge0`, with the -following contents: - - create - !brconfig $int add ne0 add ne1 up - -After setting up the bridge the bridge configuration can be displayed using the -`brconfig -a` command. Remember that if you want to give the bridge machine an -IP address you can only allocate an IP address to one of the interfaces which -are part of the bridge. - -## A common LAN setup - -The small home network discussed in the previous section contained many items -that were configured manually. In bigger LANs that are centrally managed, one -can expect Internet connectivity being available via some router, a DNS server -being available, and most important, a DHCP server which hands out IP addresses -to clients on request. To make a NetBSD client run in such an environment, it's -usually enough to set - - dhclient=yes - -in `/etc/rc.conf`, and the IP address will be set automatically, -`/etc/resolv.conf` will be created and routing setup to the default router. - -## Connecting two PCs through a serial line - -If you need to transfer files between two PCs which are not networked there is a -simple solution which is particularly handy when copying the files to a floppy -is not practical: the two machines can be networked with a serial cable (a *null -modem* cable). The following sections describe some configurations. - -### Connecting NetBSD with BSD or Linux - -The easiest case is when both machines run NetBSD: making a connection with the -SLIP protocol is very easy. On the first machine write the following commands: - - # slattach /dev/tty00 - # ifconfig sl0 inet 192.168.1.1 192.168.1.2 - -On the second machine write the following commands: - - # slattach /dev/tty00 - # ifconfig sl0 inet 192.168.1.2 192.168.1.1 - -Now you can test the connection with `ping`; for example, on the second PC -write: - - # ping 192.168.1.1 - -If everything worked there is now an active network connection between the two -machines and ftp, telnet and other similar commands can be executed. The textual -aliases of the machines can be written in the `/etc/hosts` file. - - * In the previous example both PCs used the first serial port (`/dev/tty0`). - Substitute the appropriate device if you are using another port. - - * IP addresses like 192.168.x.x are reserved for `internal` networks. The first - PC has address 192.168.1.1 and the second 192.168.1.2. - - * To achieve a faster connection the `-s speed` option to `slattach` can be - specified. - - * `ftp` can be used to transfer files only if inetd is active and the ftpd - * server is enabled. - -### Linux - -If one of the two PCs runs Linux, the commands are slightly different (on the -Linux machine only). If the Linux machine gets the 192.168.1.2 address, the -following commands are needed: - - # slattach -p slip -s 115200 /dev/ttyS0 & - # ifconfig sl0 192.168.1.2 pointopoint 192.168.1.1 up - # route add 192.168.1.1 dev sl0 - -Don't forget the `&` in the first command. - -### Connecting NetBSD and Windows NT - -NetBSD and Windows NT can be (almost) easily networked with a serial *null -modem* cable. Basically what needs to be done is to create a *Remote Access* -connection under Windows NT and to start pppd on NetBSD. - -Start pppd as root after having created a `.ppprc` in `/root`. Use the following -example as a template. - - connect '/usr/sbin/chat -v CLIENT CLIENTSERVER' - local - tty00 - 115200 - crtscts - lock - noauth - nodefaultroute - :192.168.1.2 - -The meaning of the first line will be explained later in this section; -192.168.1.2 is the IP address that will be assigned by NetBSD to the Windows NT -host; `tty00` is the serial port used for the connection (first serial port). - -On the NT side a *null modem* device must be installed from the Control Panel -(Modem icon) and a Remote Access connection using this modem must be created. -The null modem driver is standard under Windows NT 4 but it's not a 100% null -modem: when the link is activated, NT sends the string CLIENT and expects to -receive the answer CLIENTSERVER. This is the meaning of the first line of the -`.ppprc` file: `chat` must answer to NT when the connection is activated or -the connection will fail. - -In the configuration of the Remote Access connection the following must be -specified: use the null modem, telephone number `1` (it's not used, anyway), PPP -server, enable only TCP/IP protocol, use IP address and nameservers from the -server (NetBSD in this case). Select the hardware control flow and set the port -to 115200 8N1. - -Now everything is ready to activate the connection. - - * Connect the serial ports of the two machines with the null modem cable. - * Launch pppd on NetBSD. To see the messages of pppd: - `tail -f /var/log/messages`). - * Activate the Remote Access connection on Windows NT. - -### Connecting NetBSD and Windows 95 - -The setup for Windows 95 is similar to the one for Windows NT: Remote Access on -Windows 95 and the PPP server on NetBSD will be used. Most (if not all) Windows -95 releases don't have the *null modem* driver, which makes things a little more -complicated. The easiest solution is to find one of the available null modem -drivers on the Internet (it's a small `.INF` file) and repeat the same steps as -for Windows NT. The only difference is that the first line of the `.ppprc` file -(the one that calls `chat`) can be removed. - -If you can't find a real null modem driver for Windows 95 it's still possible to -use a little trick: - - * Create a Remote Access connection like the one described before for Windows - NT, but using the *Standard Modem*. - - * In `.ppprc` substitute the line that calls `chat` with the following line - - connect '/usr/sbin/chat -v ATH OK AT OK ATE0V1 OK AT OK ATDT CONNECT' - - * Activate the connection as described in the section before for Windows NT. - - -In this way the `chat` program, called when the connection is activated, -emulates what Windows 95 thinks is a standard modem, returning to Windows 95 the -same answers that a standard modem would return. Whenever Windows 95 sends a -modem command string, `chat` returns OK. - -## IPv6 Connectivity & Transition via 6to4 - -This section will concentrate on how to get network connectivity for IPv6 and - -as that is rarely available directly - talk at length about the alternatives to -native IPv6 connectivity as a transitional method until native IPv6 peers are -available. - -Finding an ISP that offers IPv6 natively needs quite some luck. What you need -next is a router that will be able to handle the traffic. To date, not all -router manufacturers offer IPv6 or hardware accelerated IPv6 features, and -gateway NAT boxes only rarely support IPv6 and also block IPv6 tunnels. An -alternative approach involves configuring a standard PC running NetBSD to act as -a router. The base NetBSD system contains a complete IPv6 routing solution, and -for special routing needs software like Zebra can provide additional routing -protocols. This solution is rather common for sites that want IPv6 -connectivity today. The drawbacks are that you need an ISP that supports -IPv6 and that you may need a dedicated uplink only for IPv6. - -IPv6 to-the-door may be rare, but you can still get IPv6 connectivity by using -tunnels. Instead of talking IPv6 on the wire, the IPv6 packets are encapsulated -in IPv4 packets, as shown in the next image. Using the existing IPv4 -infrastructure, the encapsulated packets are sent to a IPv6-capable uplink that -will then remove the encapsulation, and forward the IPv6 packets. - -![A frequently used method for transition is tunneling IPv6 in IPv4 packets](/guide/images/ipv6-en-2tunnel.gif) -**A frequently used method for transition is tunneling IPv6 in IPv4 packets** - -When using tunnels, there are two possibilities. One is to use a so-called -*configured* tunnel, the other is called an *automatic* tunnel. A *configured* -tunnel is one that required preparation from both ends of the tunnel, usually -connected with some kind of registration to exchange setup information. An -example for such a configured tunnel is the IPv6-over-IPv4 encapsulation -described in -[RFC1933](http://tools.ietf.org/html/rfc1933) ("RFC 1933: Transition Mechanisms -for IPv6 Hosts and Routers"), and that's implemented e.g. by the -[[!template id=man name="gif" section="4"]] -device found in NetBSD. - -An *automatic* tunnel consists of a public server that has some kind of IPv6 -connectivity, e.g. via 6Bone. That server has made its connectivity data public, -and also runs a tunneling protocol that does not require an explicit -registration of the sites using it as uplink. A well-used example of such a -protocol is the 6to4 mechanism described in -[RFC3056](http://tools.ietf.org/html/rfc3056) ("RFC 3056: Connection of IPv6 -Domains via IPv4 Clouds"), and that is implemented in the -[[!template id=man name="stf" section="4"]] device -found in NetBSD's. Another mechanism that does not require registration of -IPv6-information is the 6over4 mechanism, which implements transporting of IPv6 -over a multicast-enabled IPv4 network, instead of e.g. ethernet or FDDI. 6over4 -is documented in [RFC2529](http://tools.ietf.org/html/rfc2529) ("RFC 2529: -Transmission of IPv6 over IPv4 Domains without Explicit Tunnels"). It's main -drawback is that you do need existing multicast infrastructure. If you don't -have that, setting it up is about as much effort as setting up a configured IPv6 -tunnel directly, so it's usually not worth bothering in that case. - -### Getting 6to4 IPv6 up & running - -6to4 is an easy way to get IPv6 connectivity for hosts that only have an IPv4 -uplink, especially if you have the background given in -[[the chapter about IPv6|guide/net-intro#ipv6-intro]]. It can be used with -static as well as dynamically assigned IPv4 addresses, e.g. as found in modem -dialup scenarios today. When using dynamic IPv4 addresses, a change of IP -addresses will be a problem for incoming traffic, i.e. you can't run persistent -servers. - -Example configurations given in this section are for NetBSD 1.5.2. - -### Obtaining IPv6 Address Space for 6to4 - -The 6to4 IPv6 setup on your side doesn't consist of a single IPv6 address; -Instead, you get a whole /48 network! The IPv6 addresses are derived from your -(single) IPv4 address. The address prefix *2002:` is reserved for 6to4 based -addresses (i.e. IPv6 addresses derived from IPv4 addresses). The next 32 bits -are your IPv4 address. This results in a /48 network that you can use for your -very own purpose. It leaves 16 bits space for 2^16^ IPv6 subnets, which can take -up to 2^64^ nodes each. The next figure illustrates the building of your IPv6 -address (range) from your IPv4 address. - -Thanks to the 6to4 prefix and your worldwide unique IPv4 address, this address -block is unique, and it's mapped to your machine carrying the IPv4 address in -question. - -![6to4 derives an IPv6 from an IPv4 address](/guide/images/ipv6-en-3adr.gif) -**6to4 derives an IPv6 from an IPv4 address** - -### How to get connected - -In contrast to the configured *IPv6-over-IPv4 tunnel* setup, you do not have to -register at a 6bone-gateway, which would only then forward your IPv6 traffic -encapsulated in IPv4. Instead, as your IPv6 address is derived from your IPv4 -address, inbound traffic can be sent through the nearest 6to4 relay router. -De-encapsulation of the packet is done via a 6to4-capable network interface, -which then forwards the resulting IPv6 packet according to your routing setup -(in case you have more than one machine connected on your 6to4 assigned -network). - -To transmit IPv6 packets, the 6to4 router will encapsulate them inside IPv4 -packets; a system performing these functions is called a 6to4 border router. -These packets have a default route to the *6to4 relay anycast prefix*. This -anycast prefix will route the tunnel to a *6to4 relay router*. - -![Request and reply can be routed via different gateways in 6to4](/guide/images/ipv6-en-1scene.gif) -**Request and reply can be routed via different gateways in 6to4** - -### Security Considerations - -In contrast to the *configured tunnel* setup, you usually can't setup packet -filters to block 6to4-packets from unauthorized sources, as this is exactly how -(and why) 6to4 works at all. As such, malicious users can send packets with -invalid/hazardous IPv6 payload. If you don't already filter on your border -gateways anyways, packets with the following characteristics should not be -allowed as valid 6to4 packets, and some firewalling seems to be justified for -them: - - * unspecified IPv4 source/destination address: 0.0.0.0/8 - * loopback address in outer (v4) source/destination: 127.0.0.0/8 - * IPv4 multicast in source/destination: 224.0.0.0/4 - * limited broadcasts: 255.0.0.0/8 - * subnet broadcast address as source/destination: depends on your IPv4 setup - -The NetBSD -[[!template id=man name="stf" section="4"]] manual -page documents some common configuration mistakes intercepted by default by the -KAME stack as well as some further advice on filtering, but keep in mind that -because of the requirement of these filters, 6to4 is not perfectly secure. -Still, if forged 6to4 packets become a problem, you can use IPsec authentication -to ensure the IPv6 packets are not modified. - -### Data Needed for 6to4 Setup - -In order to setup and configure IPv6 over 6to4, a few bits of configuration data -must be known in advance. These are: - - * Your local IPv4 address. It can be determined using either the `ifconfig -a` - or `netstat -i` commands on most Unix systems. If you use a NATing gateway or - something, be sure to use the official, outside-visible address, not your - private (10/8 or 192.168/16) one. - - We will use 62.224.57.114 as the local IPv4 address in our example. - - * Your local IPv6 address, as derived from the IPv4 address. See the previous - figure ("6to4 derives an IPv6 from an IPv4 address") about how to do so. - - For our example, this is 2002:3ee0:3972:0001::1 (62.224.57.114 == 0x3ee03972, - 0001::1 arbitrarily chosen). - - * The *6to4 IPv6 relay anycast address*. which is 2002:c058:6301::, or the IPv6 - address of a specific 6to4 relay router you want to use. The IPv6 address - will do, as it also contains the IPv4 address in the usual 6to4 translation. - -### Kernel Preparation - -To process 6to4 packets, the operating system kernel needs to know about them. -For that a driver has to be compiled in that knows about 6to4, and how to handle -it. In NetBSD 4.0 and newer, the driver is already present in GENERIC kernel -configurations, so the procedure below is usually unnecessary. - -For a NetBSD kernel, put the following into your kernel config file to prepare -it for using IPv6 and 6to4, e.g. on NetBSD use: - - options INET6 # IPv6 - pseudo-device stf # 6to4 IPv6 over IPv4 encapsulation - -Note that the -[[!template id=man name="stf" section="4"]] device is -not enabled by default on NetBSD releases older than 4.0. Rebuild your kernel, -then reboot your system to use the new kernel. Please consult -[[Compiling the kernel|guide/kernel]] for further information on configuring, -building and installing a new kernel! - -### 6to4 Setup - -This section describes the commands to setup 6to4. In short, the steps performed -here are: - - 1. Configure interface - 2. Set default route - 3. Setup Router Advertisement, if wanted - -The first step in setting up 6to4 is creating the 6to4 interface and assigning -an IPv6 address to it. This is achieved with the -[[!template id=man name="ifconfig" section="8"]] -command. Assuming the example configuration above, the commands for NetBSD are: - - # ifconfig stf0 create - # ifconfig stf0 inet6 2002:3ee0:3972:1::1 prefixlen 16 alias - -After configuring the 6to4 device with these commands, routing needs to be -setup, to forward all tunneled IPv6 traffic to the 6to4 relay router. The best -way to do this is by setting a default route, the command to do so is, for -NetBSD: - - # route add -inet6 default 2002:c058:6301:: - -Note that NetBSD's -[[!template id=man name="stf" section="4"]] device -determines the IPv4 address of the 6to4 uplink from the routing table. Using -this feature, it is easy to setup your own 6to4 (uplink) gateway if you have an -IPv6 uplink, e.g. via 6Bone. - -After these commands, you are connected to the IPv6-enabled world - -Congratulations! Assuming name resolution is still done via IPv4, you can now -ping an IPv6-site like www.kame.net or www6.NetBSD.org: - - # /sbin/ping6 www.kame.net - -As a final step in setting up IPv6 via 6to4, you will want to setup Router -Advertisement if you have several hosts on your network. While it is possible to -setup 6to4 on each node, doing so will result in very expensive routing from one -node to the other - packets will be sent to the remote 6to4 gateway, which will -then route the packets back to the neighbor node. Instead, setting up 6to4 on -one machine and talking native IPv6 on-wire is the preferred method of handling -things. - -The first step to do so is to assign an IPv6-address to your ethernet. In the -following example we will assume subnet `2` of the IPv6-net is used for the -local ethernet and the MAC address of the ethernet interface is -12:34:56:78:9a:bc, i.e. your local gateway's ethernet interface's IP address -will be 2002:3ee0:3972:2:1234:56ff:fe78:9abc. Assign this address to your -ethernet interface, e.g. - - # ifconfig ne0 inet6 alias 2002:3ee0:3972:2:1234:56ff:fe78:9abc - -Here, `ne0` is an example for your ethernet card interface. This will most -likely be different for your setup, depending on what kind of card is used. - -Next thing that needs to be ensured for setting up the router is that it will -actually forward packets from the local 6to4 device to the ethernet device and -back. To enable IPv6 packet forwarding, set `ip6mode=router` in NetBSD's -`/etc/rc.conf`, which will result in the `net.inet6.ip6.forwarding` sysctl being -set to `1`: - - # sysctl -w net.inet6.ip6.forwarding=1 - -![Enabling packet forwarding is needed for a 6to4 router](/guide/images/ipv6-en-5forward.gif) -**Enabling packet forwarding is needed for a 6to4 router** - -To setup router advertisement on BSD, the file `/etc/rtadvd.conf` needs to be -checked. It allows configuration of many things, but usually the default config -of not containing any data is ok. With that default, IPv6 addresses found on all -of the router's network interfaces will be advertised. - -After checking the router advertisement configuration is correct and IPv6 -forwarding is turned on, the daemon handling it can be started. Under NetBSD, it -is called `rtadvd`. Start it up either manually (for testing it the first time) -or via the system's startup scripts, and see all your local nodes automagically -configure the advertised subnet address in addition to their already-existing -link local address. - - # rtadvd - -### Quickstart using pkgsrc/net/hf6to4 - -So far, we have described how 6to4 works and how to set it up manually. For an -automated way to make everything happen e.g. when going online, the 'hf6to4' -package is convenient. It will determine your IPv6 address from the IPv4 address -you got assigned by your provider, then set things up that you are connected. - -Steps to setup the pkgsrc/net/hf6to4 package are: - - 1. Install the package either by compiling it from pkgsrc, or by `pkg_add`'ing - the 6to4-1.2 package. - - # cd /usr/pkgsrc/net/hf6to4 - # make install - - 2. Make sure you have the - [[!template id=man name="stf" section="4"]] - pseudo-device in your kernel, see above. - - 3. Configure the 'hf6to4' package. First, copy - `/usr/pkg/share/examples/hf6to4/hf6to4.conf` to `/usr/pkg/etc/hf6to4.conf`, - then adjust the variables. Note that the file is in /bin/sh syntax. - - # cd /usr/pkg/etc - # cp ../share/examples/hf6to4/hf6to4.conf hf6to4.conf - # vi hf6to4.conf - - Please see the - [[!template id=man name="hf6to4" section="8"]] - manpage for an explanation of all the variables you can set in - `hf6to4.conf`. If you have dialup IP via PPP, and don't want to run Router - Advertizing for other IPv6 machines on your home or office network, you - don't need to configure anything. If you want to setup Router Advertising, - you need to set the `in_if` to the internal (ethernet) interface, e.g. - - $in_if="rtk0"; # Inside (ethernet) interface - - 4. Now dial up, then start the 6to4 command manually: - - # /usr/pkg/sbin/hf6to4 start - - 5. After that, you should be connected, use - [[!template id=man name="ping6" section="8"]]: to - see if everything works: - - # ping6 www.NetBSD.org - PING6(56=40+8+8 bytes) 2002:d954:110b:1::1 --> 2001:4f8:4:7:2e0:81ff:fe52:9a6b - 16 bytes from 2001:4f8:4:7:2e0:81ff:fe52:9a6b, icmp_seq=0 hlim=60 time=250.234 ms - 16 bytes from 2001:4f8:4:7:2e0:81ff:fe52:9a6b, icmp_seq=1 hlim=60 time=255.652 ms - 16 bytes from 2001:4f8:4:7:2e0:81ff:fe52:9a6b, icmp_seq=2 hlim=60 time=251.237 ms - ^C - --- www.NetBSD.org ping6 statistics --- - 3 packets transmitted, 3 packets received, 0.0% packet loss - round-trip min/avg/max/std-dev = 250.234/252.374/255.652/2.354 ms - - # traceroute6 www.NetBSD.org - traceroute6 to www.NetBSD.org (2001:4f8:4:7:2e0:81ff:fe52:9a6b) - from 2002:d954:110b:1::1, 64 hops max, 12 byte packets - 1 2002:c25f:6cbf:1::1 66.31 ms 66.382 ms 69.062 ms - 2 nr-erl1.6win.dfn.de 76.134 ms * 76.87 ms - 3 nr-fra1.6win.dfn.de 76.371 ms 80.709 ms 79.482 ms - 4 dfn.de6.de.6net.org 92.763 ms 90.863 ms 94.322 ms - 5 de.nl6.nl.6net.org 116.115 ms 93.463 ms 96.331 ms - 6 nl.uk6.uk.6net.org 103.347 ms 99.334 ms 100.803 ms - 7 uk1.uk61.uk.6net.org 99.481 ms 100.421 ms 100.119 ms - 8 2001:798:28:300::2 89.711 ms 90.435 ms 90.035 ms - 9 ge-1-0-0-2.r20.londen03.uk.bb.verio.net 179.671 ms 185.141 ms 185.86 ms - 10 p16-0-0-0.r81.nycmny01.us.bb.verio.net 177.067 ms 179.086 ms 178.05 ms - 11 p16-1-1-3.r20.nycmny01.us.bb.verio.net 178.04 ms 179.727 ms 184.165 ms - 12 p16-0-1-1.r20.mlpsca01.us.bb.verio.net 249.856 ms 247.476 ms 249.012 ms - 13 p64-0-0-0.r21.snjsca04.us.bb.verio.net 239.691 ms 241.404 ms 240.998 ms - 14 p64-0-0-0.r21.plalca01.us.bb.verio.net 247.541 ms 246.661 ms 246.359 ms - 15 xe-0-2-0.r20.plalca01.us.bb.verio.net 240.987 ms 239.056 ms 241.251 ms - 16 ge-6-1.a01.snfcca05.us.ra.verio.net 240.868 ms 241.29 ms 242.337 ms - 17 fa-5-2.a01.snfcca05.us.ce.verio.net 249.477 ms 250.4 ms 256.035 ms - 18 2001:4f8:4:7:2e0:81ff:fe52:9a6b 268.164 ms 252.97 ms 252.366 ms - - Please note that `traceroute6` shows the v6 hops only, any underlying - tunnels are invisible and thus not displayed. - - 6. If this works, you can put the following lines into your `/etc/ppp/ip-up` - script to run the command each time you go online: - - logger -p user.info -t ip-up Configuring 6to4 IPv6 - /usr/pkg/sbin/hf6to4 stop - /usr/pkg/sbin/hf6to4 start - - 7. If you want to route IPv6 for your LAN, you can instruct `6to4.pl` to setup - Router Advertising for you too: - - # /usr/pkg/sbin/hf6to4 rtadvd-start - - You can put that command into `/etc/ppp/ip-up` as well to make it permanent. - - 8. If you have changed `/etc/ppp/ip-up` to setup 6to4 automatically, you will - most likely want to change `/etc/ppp/ip-down` too, to shut it down when you - go offline. Here's what to put into `/etc/ppp/ip-down`: - - logger -p user.info -t ip-down Shutting down 6to4 IPv6 - /usr/pkg/sbin/hf6to4 rtadvd-stop - /usr/pkg/sbin/hf6to4 stop - -### Known 6to4 Relay Routers - -It is normally not necessary to pick a specific 6to4 relay router, but if -necessary, you may find a list of known working routers at -[http://www.kfu.com/\~nsayer/6to4/](http://www.kfu.com/~nsayer/6to4/). In tests, -only 6to4.kfu.com and 6to4.ipv6.microsoft.com were found working. Cisco has one -that requires registration, see -[http://www.cisco.com/ipv6/](http://www.cisco.com/ipv6/). - -There's also an experimental 6to4 server located in Germany, -6to4.ipv6.fh-regensburg.de. This server runs under NetBSD 1.6 and was setup -using the configuration steps described above. The whole configuration of the -machine can be seen at -[http://www.feyrer.de/IPv6/netstart.local](http://www.feyrer.de/IPv6/netstart.local). - -### Tunneling 6to4 through an IPFilter firewall - -The 6to4 protocol encapsulates IPv6 packets in IPv4, and gives them their own IP -type, which most firewalls block as unknown, as their payload type is directly -`TCP`, `UDP` or `ICMP`. Usually, you want to setup your 6to4 gateway on the same -machine that is directly connected to the (IPv4) internet, and which usually -runs the firewall. For the case that you want to run your 6to4 gateway behind a -firewall, you need to drill a hole into the firewall, to let 6to4 packets -through. Here is how to do this! - -The example assumes that you use the `ppp0` interface on your firewall to -connect to the Internet. - -Put the following lines into `/etc/ipf.conf` to allow your IPFilter firewall let -all 6to4 packets pass (lines broken with `\` due to space restrictions; please -put them lines continued that way all in one line): - - # Handle traffic by different rulesets - block in quick on ppp0 all head 1 - block out quick on ppp0 all head 2 - - ### Incoming packets: - # allow some IPv4: - pass in log quick on ppp0 proto tcp from any to any \ - port = www flags S keep state keep frags group 1 - pass in quick on ppp0 proto tcp from any to any \ - port = ssh keep state group 1 - pass in quick on ppp0 proto tcp from any to any \ - port = mail keep state group 1 - pass in log quick on ppp0 proto tcp from any to any \ - port = ftp keep state group 1 - pass in log quick on ppp0 proto tcp from any to any \ - port = ftp-data keep state group 1 - pass in log quick on ppp0 proto icmp from any to any group 1 - # allow all IPv6: - pass in quick on ppp0 proto ipv6 from any to any group 1 - pass in log quick on ppp0 proto ipv6-route from any to any group 1 - pass in log quick on ppp0 proto ipv6-frag from any to any group 1 - pass in log quick on ppp0 proto ipv6-icmp from any to any group 1 - pass in log quick on ppp0 proto ipv6-nonxt from any to any group 1 - pass in log quick on ppp0 proto ipv6-opts from any to any group 1 - # block rest: - blockin log quick on ppp0 all group 1 - - ### Outgoing packets: - # allow usual stuff: - pass out quick on ppp0 proto tcp from any to any flags S \ - keep state keep frags group 2 - pass out quick on ppp0 proto udp from any to any \ - keep state keep frags group 2 - pass out quick on ppp0 proto icmp from any to any \ - keep state group 2 - # allow all IPv6: - pass out quick on ppp0 proto ipv6 from any to any group 2 - pass out log quick on ppp0 proto ipv6-route from any to any group 2 - pass out log quick on ppp0 proto ipv6-frag from any to any group 2 - pass out log quick on ppp0 proto ipv6-icmp from any to any group 2 - pass out log quick on ppp0 proto ipv6-nonxt from any to any group 2 - pass out log quick on ppp0 proto ipv6-opts from any to any group 2 - # block rest: - block out log quick on ppp0 all group 2 - -Now any host on your network can send (the `out` rules) and receive (the `in` -rules) v4-encapsulated IPv6 packets, allowing setup of any of them as a 6to4 -gateway. Of course you only want to do this on one host and use native IPv6 -between your hosts, and you may also want to enforce this with more restrictive -rulesets, please see -[[!template id=man name="ipf.conf" section="5"]] -for more information on IPFilter rules. - -After your firewall lets pass encapsulated IPv6 packets, you may want to set up -your 6to4 gateway to monitor the IPv6 traffic, or even restrict it. To do so, -you need to setup IPFilter on your 6to4 gateway as well. For basic monitoring, -enable `ipfilter=yes` in `/etc/rc.conf` and put the following into -`/etc/ipf6.conf`: - - pass in log quick on stf0 from any to any - pass out log quick on stf0 from any to any - -This logs all (IPv6) traffic going in and out of your `stf0` tunneling -interface. You can add filter rules as well if needed. - -If you are more interested in traffic stats than a general overview of your -network traffic, using MRTG in conjunction with the `net-snmp` package is -recommended instead of analyzing IPFilter log files. - -### Conclusion & Further Reading - -Compared to where IPv4 is today, IPv6 is still in its early steps. It is -working, there are all sort of services and clients available, only the userbase -is missing. It is hoped the information provided here helps people better -understand what IPv6 is, and to start playing with it. - -A few links should be mentioned here for interested parties: - - * An example script to setup 6to4 on BSD based machines is available at - . The script determines your IPv6 - address and sets up 6to4 and (if wanted) router advertising. It was designed - to work in dialup setups with changing IPv4 addresses. - - * Given that there isn't a standard for IPv6 in Linux land today, there are - different setup instructions for most distributions. The setup of IPv6 on - Debian GNU/Linux can be found at - [http://people.debian.org/\~csmall/ipv6/setup.html](http://people.debian.org/~csmall/ipv6/setup.html). - - * The BSD Unix implementations have their own IPv6 documentation each, - interesting URLs are for NetBSD, - - for FreeBSD. - - * Projects working on implementing IPv6 protocol stacks for free Unix like - operating systems are KAME for BSD and USAGI for Linux. Their web sites can - be found at and . A list - of host and router implementations can be found at - . - - * Besides the official RFC archive at , information - on IPv6 can be found at several web sites. First and foremost, the 6Bone's - web page at must be mentioned. 6Bone was started as - the testbed for IPv6, and is now an important part of the IPv6-connected - world. Other web pages that contain IPv6-related contents include - , and - . Most of these sites carry further links - be - sure to have a look! - +This page was moved to: +[The NetBSD Guide - Setting up TCP/IP on NetBSD in practice](//www.NetBSD.org/docs/guide/en/chap-net-practice.html)