Bird is a commonly used BGP daemon. This page provides configuration and help to run Bird for dn42. Compared to quagga, bird supports multiple routing tables, which is useful, if you also plan to peer with other federated networks such as freifunk. In the following a working configuration for dn42 is shown. If you want to learn the practical details behind routing protocols in bird, see the following [guide](https://github.com/knorrie/network-examples) **Bird 1.6.x will be EOL by the end of 2023, it's recommended to upgrade to 2.13.** # Debian In the Debian release cycle the bird packages may become outdated at times, if that is the case you should use the official bird package repository maintained by the developers of nic.cz. This is not necessary for Debian Stretch, which currently ships the most recent version (1.6.3) in this repositories. ```sh echo "deb http://deb.debian.org/debian buster-backports main" > /etc/apt/sources.list.d/buster-backports.list apt update apt install bird ``` # Example configuration Note: This file covers the configuration of Bird 1.x. For an example configuration of Bird 2.x see [howto/Bird2](/howto/Bird2) * Replace `` with your Autonomous System Number (only the digits) * Replace `` with your gateway ip (the internal dn42 ip address you use on the host, where dn42 is running) * Replace `` with your registered dn42 subnet * Replace `` with the ip of your peer who is connected with you using your favorite vpn protocol (openvpn, ipsec, tinc, ...) * Replace `` the Autonomous System Number of your peer (only the digits) * Replace `` a self chosen name for your peer ## IPv6 ```conf #/etc/bird/bird6.conf protocol device { scan time 10; } # local configuration ###################### include "/etc/bird/local6.conf"; # filter helpers ################# ##include "/etc/bird/filter6.conf"; # Kernel routing tables ######################## /* krt_prefsrc defines the source address for outgoing connections. On Linux, this causes the "src" attribute of a route to be set. Without this option outgoing connections would use the peering IP which would cause packet loss if some peering disconnects but the interface is still available. (The route would still exist and thus route through the TUN/TAP interface but the VPN daemon would simply drop the packet.) */ protocol kernel { scan time 20; import none; export filter { if source = RTS_STATIC then reject; krt_prefsrc = OWNIP; accept; }; } # static routes ################ protocol static { route reject; import all; export none; } template bgp dnpeers { local as OWNAS; path metric 1; import keep filtered; import filter { if is_valid_network() && !is_self_net() then { accept; } reject; }; export filter { if is_valid_network() && source ~ [RTS_STATIC, RTS_BGP] then { accept; } reject; }; import limit 1000 action block; } include "/etc/bird/peers6/*"; ``` ```conf # /etc/bird/local6.conf # should be a unique identifier, use same id as for ipv4 router id ; define OWNAS = ; define OWNIP = ; function is_self_net() { return net ~ [+]; } function is_valid_network() { return net ~ [ fd00::/8{44,64} # ULA address space as per RFC 4193 ]; } ``` ```conf # /etc/bird/peers6/ protocol bgp from dnpeers { neighbor as ; # if you use link-local ipv6 addresses for peering using the following # neighbor % '' as ; }; ``` ### IPv4 ```conf # /etc/bird/bird.conf # Device status protocol device { scan time 10; # recheck every 10 seconds } protocol static { # Static routes to announce your own range(s) in dn42 route reject; import all; export none; }; # local configuration ###################### # keeping router specific in a seperate file, # so this configuration can be reused on multiple routers in your network include "/etc/bird/local4.conf"; # filter helpers ################# ##include "/etc/bird/filter4.conf"; # Kernel routing tables ######################## /* krt_prefsrc defines the source address for outgoing connections. On Linux, this causes the "src" attribute of a route to be set. Without this option outgoing connections would use the peering IP which would cause packet loss if some peering disconnects but the interface is still available. (The route would still exist and thus route through the TUN/TAP interface but the VPN daemon would simply drop the packet.) */ protocol kernel { scan time 20; import none; export filter { if source = RTS_STATIC then reject; krt_prefsrc = OWNIP; accept; }; }; # DN42 ####### template bgp dnpeers { local as OWNAS; # metric is the number of hops between us and the peer path metric 1; # this lines allows debugging filter rules # filtered routes can be looked up in birdc using the "show route filtered" command import keep filtered; import filter { # accept every subnet, except our own advertised subnet # filtering is important, because some guys try to advertise routes like 0.0.0.0 if is_valid_network() && !is_self_net() then { accept; } reject; }; export filter { # here we export the whole net if is_valid_network() && source ~ [RTS_STATIC, RTS_BGP] then { accept; } reject; }; import limit 1000 action block; #source address OWNIP; }; include "/etc/bird/peers4/*"; ``` ```conf #/etc/bird/local4.conf # should be a unique identifier, is what most people use. router id ; define OWNAS = ; define OWNIP = ; function is_self_net() { return net ~ [+]; } function is_valid_network() { return net ~ [ 172.20.0.0/14{21,29}, # dn42 172.20.0.0/24{28,32}, # dn42 Anycast 172.21.0.0/24{28,32}, # dn42 Anycast 172.22.0.0/24{28,32}, # dn42 Anycast 172.23.0.0/24{28,32}, # dn42 Anycast 172.31.0.0/16+, # ChaosVPN 10.100.0.0/14+, # ChaosVPN 10.127.0.0/16{16,32}, # neonetwork 10.0.0.0/8{15,24} # Freifunk.net ]; } ``` ```conf # /etc/bird/peers4/ protocol bgp from dnpeers { neighbor as ; }; ``` # Bird communities Communities can be used to prioritize traffic based on different flags, in DN42 we are using communities to prioritize based on latency, bandwidth and encryption. It is really easy to get started with communities and we encourage all of you to get the basic configuration done and to mark your peerings with the correct flags for improved routing. More information can be found [here](/howto/BGP-communities). # Route Origin Authorization Route Origin Authorizations should be used in BIRD to authenticate prefix announcements. These check the originating AS and validate that they are allowed to advertise a prefix. ## ROA Tables The ROA table can be generated from the registry directly or you can use pre-built ROA tables. ### Updating ROA tables You can add cron entries to periodically update the tables: ```conf */15 * * * * curl -sfSLR {-o,-z}/var/lib/bird/bird6_roa_dn42.conf https://dn42.burble.com/roa/dn42_roa_bird1_6.conf && chronic birdc6 configure */15 * * * * curl -sfSLR {-o,-z}/var/lib/bird/bird_roa_dn42.conf https://dn42.burble.com/roa/dn42_roa_bird1_4.conf && chronic birdc configure ``` Debian version: ```conf */15 * * * * curl -sfSLR -o/var/lib/bird/bird6_roa_dn42.conf -z/var/lib/bird/bird6_roa_dn42.conf https://dn42.burble.com/roa/dn42_roa_bird1_6.conf && /usr/sbin/birdc6 configure */15 * * * * curl -sfSLR -o/var/lib/bird/bird_roa_dn42.conf -z/var/lib/bird/bird_roa_dn42.conf https://dn42.burble.com/roa/dn42_roa_bird1_4.conf && /usr/sbin/birdc configure ``` then create the directory to make sure curls can save the files: ```sh mkdir -p /var/lib/bird/ ``` Or use a systemd timer: (check the commands before copy-pasting) ```conf # /etc/systemd/system/dn42-roa.service [Unit] Description=Update DN42 ROA [Service] Type=oneshot ExecStart=curl -sfSLR -o /etc/bird/roa_dn42.conf -z /etc/bird/roa_dn42.conf https://dn42.burble.com/roa/dn42_roa_bird2_4.conf ExecStart=curl -sfSLR -o /etc/bird/roa_dn42_v6.conf -z /etc/bird/roa_dn42_v6.conf https://dn42.burble.com/roa/dn42_roa_bird2_6.conf ExecStart=birdc configure ``` ```conf # /etc/systemd/system/dn42-roa.timer [Unit] Description=Update DN42 ROA periodically [Timer] OnBootSec=2m OnUnitActiveSec=15m AccuracySec=1m [Install] WantedBy=timers.target ``` then enable and start the timer with `systemctl enable --now dn42-roa.timer`. More advanced script with error checking: ```sh #!/bin/bash roa4URL="" roa6URL="" roa4FILE="/etc/bird/roa/roa_dn42.conf" roa6FILE="/etc/bird/roa/roa_dn42_v6.conf" cp "${roa4FILE}" "${roa4FILE}.old" cp "${roa6FILE}" "${roa6FILE}.old" if curl -f -o "${roa4FILE}.new" "${roa4URL};" ;then mv "${roa4FILE}.new" "${roa4FILE}" fi if curl -f -o "${roa6FILE}.new" "${roa6URL};" ;then mv "${roa6FILE}.new" "${roa6FILE}" fi if birdc configure ; then rm "${roa4FILE}.old" rm "${roa6FILE}.old" else mv "${roa4FILE}.old" "${roa4FILE}" mv "${roa6FILE}.old" "${roa6FILE}" fi ``` ### Use RPKI ROA in bird2 * Download gortr * Run gortr. ```sh ./gortr -verify=false -checktime=false -cache=https://dn42.burble.com/roa/dn42_roa_46.json ``` * Run with docker ```sh docker pull cloudflare/gortr ``` ```sh docker run --name dn42rpki -p 8282:8282 --restart=always -d cloudflare/gortr -verify=false -checktime=false -cache=https://dn42.burble.com/roa/dn42_roa_46.json ``` * Add this to your bird configure file,other ROA protocol must removed. ```conf protocol rpki rpki_dn42{ roa4 { table dn42_roa; }; roa6 { table dn42_roa_v6; }; remote "" port 8282; retry keep 90; refresh keep 900; expire keep 172800; } ``` ## Filter configuration In your import filter add the following to reject invalid routes: ```conf if (roa_check(dn42_roa, net, bgp_path.last) != ROA_VALID) then { print "[dn42] ROA check failed for ", net, " ASN ", bgp_path.last; reject; } ``` Also, define your ROA table with: ```conf roa table dn42_roa { include "/var/lib/bird/bird_roa_dn42.conf"; }; ``` **NOTE**: Make sure you setup ROA checks for both bird and bird6 (for IPv6). # Useful bird commmands bird can be remote controlled via the `birdc` command. Here is a list of useful bird commands: ```sh $ birdc BIRD 1.4.5 ready. bird> configure # reload configuration Reading configuration from /etc/bird.conf Reconfigured bird> show ? # Completions work either by pressing tab or pressing '?' show bfd ... Show information about BFD protocol show interfaces Show network interfaces show memory Show memory usage show ospf ... Show information about OSPF protocol show protocols [ | ""] Show routing protocols show roa ... Show ROA table show route ... Show routing table show static [] Show details of static protocol show status Show router status show symbols ... Show all known symbolic names bird> show protocols # this command shows your peering status name proto table state since info device1 Device master up 07:20:25 kernel1 Kernel master up 07:20:25 chelnok BGP master up 07:20:29 Established hax404 BGP master up 07:20:26 Established static1 Static master up 07:20:25 bird> show protocols all chelnok # show verbose peering status for peering with chelnok bird> show route for 172.22.141.181 # show possible routes to internal.dn42 172.22.141.0/24 via 172.23.67.1 on tobee [tobee 07:20:30] * (100) [AS64737i] via 172.23.64.1 on chelnok [chelnok 07:20:29] (100) [AS64737i] via 172.23.136.65 on hax404 [hax404 07:20:26] (100) [AS64737i] bird> show route filtered # shows routed filtered out by rules 172.23.245.1/32 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS76175i] 172.22.247.128/32 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS76175i] 172.22.227.1/32 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS76115i] 172.23.196.75/32 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS76115i] 172.22.41.241/32 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS76115i] 172.22.249.4/30 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS4242420002i] 172.22.255.133/32 via 172.23.64.1 on chelnok [chelnok 21:26:18] * (100) [AS64654i] bird> show route protocol # shows the route they export to you bird> show route export # shows the route you export to someone ... ``` # External Links * detailed bird configuration from Mic92: * more bird commands: