h1. Simple route server
Here is an example of simple BGP route server. It does not use BGP community policing. All the peers are connected into main (master) routing table. All the filtering is done in import filters and it exports everything to all the peers. (If you want to see everything what the peers are announcing to you, you can use import all; and make the filtering in export filters.)
This example saves a lot of memory compared to a Route server with community based filtering especially in environment with a lot of peers and prefixes.
/*
* Route server configuration example
*/
log "/var/log/bird.log" all;
log syslog all;
router id 9.9.9.9;
define myas = 999;
protocol device { }
# This function excludes weird networks
# rfc1918, class D, class E, too long and too short prefixes
function avoid_martians()
prefix set martians;
{
martians = [ 169.254.0.0/16+, 172.16.0.0/12+, 192.168.0.0/16+, 10.0.0.0/8+,
224.0.0.0/4+, 240.0.0.0/4+, 0.0.0.0/32-, 0.0.0.0/0{25,32}, 0.0.0.0/0{0,7} ];
# Avoid RFC1918 and similar networks
if net ~ martians then return false;
return true;
}
####
# Protocol template
template bgp PEERS {
local as myas;
import all;
export all;
import limit 10000 action restart;
rs client;
}
####
# Configuration of BGP peer follows
### AS111 - Member1
filter bgp_in_AS111
prefix set allnet;
int set allas;
{
if ! (avoid_martians()) then reject;
if (bgp_path.first != 111 ) then reject;
allas = [ 1234, 2345, 3456, 4567 ];
if ! (bgp_path.last ~ allas) then reject;
allnet = [ 12.34.0.0/16 , 23.45.0.0/16, 34.56.0.0/16, 45.56.0.0/16 ];
if ! (net ~ allnet) then reject;
accept;
}
protocol bgp R111x1 from PEERS {
description "Member 1 - peer 1";
neighbor 10.0.0.11 as 111;
import filter bgp_in_AS111;
}
protocol bgp R111x2 from PEERS {
description "Member 1 - peer 2";
neighbor 10.0.0.12 as 111;
import filter bgp_in_AS111;
}
### AS222 - Member2
filter bgp_in_AS222
prefix set allnet;
int set allas;
{
if ! (avoid_martians()) then reject;
if (bgp_path.first != 222 ) then reject;
allas = [ 4321, 5432, 6543 ];
if ! (bgp_path.last ~ allas) then reject;
allnet = [ 43.21.0.0/16 , 54.32.0.0/16, 65.43.0.0/16 ];
if ! (net ~ allnet) then reject;
accept;
}
protocol bgp R222x1 from PEERS {
description "Member 2 - peer 1";
neighbor 10.0.0.21 as 222;
import filter bgp_in_AS222;
}
### AS333 - Member3
filter bgp_in_AS333
prefix set allnet;
int set allas;
{
if ! (avoid_martians()) then reject;
if (bgp_path.first != 333 ) then reject;
allas = [ 1111, 2222, 3333, 4444, 5555, 6666 ];
if ! (bgp_path.last ~ allas) then reject;
allnet = [ 11.11.0.0/16, 22.22.0.0/16, 33.33.0.0/16, 44.44.0.0/16, 55.55.0.0/16, 66.66.0.0/16 ];
if ! (net ~ allnet) then reject;
accept;
}
protocol bgp R333x1 from PEERS {
description "Member 3 - peer 1";
neighbor 10.0.0.31 as 333;
import filter bgp_in_AS333;
}
protocol bgp R333x2 from PEERS {
description "Member 3 - peer 2";
neighbor 10.0.0.32 as 333;
import filter bgp_in_AS333;
}
protocol bgp R333x3 from PEERS {
description "Member 3 - peer 3";
neighbor 10.0.0.33 as 333;
import filter bgp_in_AS333;
}