Hello,
while I was running some tests on BIRD 2.0.0 I've noticed that the
handling of RFC8097 extended communities is different from 1.6.3.
Scenario:
- AS10 announces a route to the route server;
- the route server adds the (0x4300, 0, 1) ext community (RFC8097);
- AS20 receives the route;
- clients are always both on 1.6.3.
This is the filter I'm using:
filter from_client {
bgp_ext_community.add((unknown 0x4300, 0, 1));
accept;
}
The results I get follow:
- when 1.6.3 is used on the route server, BIRD treats the community
strictly according to RFC4360:
If a route has a non-transitivity extended community, then before
advertising the route across the Autonomous System boundary the
community SHOULD be removed from the route.
- when 2.0.0 is used, the community is treated accordingly to
draft-ietf-sidrops-route-server-rpki-light-02 and is propagated to the
client.
Since I didn't find any reference to RFC8097/rpki-light on the web site,
I was wondering if I missed something or if this is the expected
behaviour.
Configs and 'show route' output attached.
Bests,
--
Pier Carlo Chiodi
https://pierky.com
router id 192.0.2.10;
log "/var/log/bird.log" all;
log syslog all;
debug protocols all;
protocol device { }
protocol static own_prefixes {
route 1.0.1.0/24 reject;
}
protocol bgp the_rs {
local as 10;
neighbor 192.0.2.2 as 999;
import all;
export all;
connect delay time 1;
connect retry time 1;
}
router id 192.0.2.20;
log "/var/log/bird.log" all;
log syslog all;
debug protocols all;
protocol device { }
protocol bgp the_rs {
local as 20;
neighbor 192.0.2.2 as 999;
import all;
export all;
connect delay time 1;
connect retry time 1;
}
With BIRD 2.0.0 on the route server:
rs$ birdcl show route all
BIRD 2.0.0 ready.
Table master4:
1.0.1.0/24 unicast [AS10 17:33:32.159] * (100) [AS10i]
via 192.0.2.10 on eth0
Type: BGP univ
BGP.origin: IGP
BGP.as_path: 10
BGP.next_hop: 192.0.2.10
BGP.local_pref: 100
BGP.ext_community: (generic, 0x43000000, 0x1)
rs$ birdcl show route all export AS20
BIRD 2.0.0 ready.
Table master4:
1.0.1.0/24 unicast [AS10 17:33:32.159] * (100) [AS10i]
via 192.0.2.10 on eth0
Type: BGP univ
BGP.origin: IGP
BGP.as_path: 10
BGP.next_hop: 192.0.2.10
BGP.local_pref: 100
BGP.ext_community: (generic, 0x43000000, 0x1)
from the receiving client:
receiver$ birdcl show route all
BIRD 1.6.3 ready.
1.0.1.0/24 via 192.0.2.10 on eth0 [the_rs 17:33:32 from 192.0.2.2] *
(100) [AS10i]
Type: BGP unicast univ
BGP.origin: IGP
BGP.as_path: 10
BGP.next_hop: 192.0.2.10
BGP.local_pref: 100
BGP.ext_community: (generic, 0x43000000, 0x1)
With BIRD 1.6.3 on the route server:
rs$ birdcl show route all
BIRD 1.6.3 ready.
1.0.1.0/24 via 192.0.2.10 on eth0 [AS10 17:36:56] * (100) [AS10i]
Type: BGP unicast univ
BGP.origin: IGP
BGP.as_path: 10
BGP.next_hop: 192.0.2.10
BGP.local_pref: 100
BGP.ext_community: (generic, 0x43000000, 0x1)
rs$ birdcl show route all export AS20
BIRD 1.6.3 ready.
1.0.1.0/24 via 192.0.2.10 on eth0 [AS10 17:36:56] * (100) [AS10i]
Type: BGP unicast univ
BGP.origin: IGP
BGP.as_path: 10
BGP.next_hop: 192.0.2.10
BGP.local_pref: 100
BGP.ext_community: (generic, 0x43000000, 0x1)
from the receiving client:
receiver$ birdcl show route all
BIRD 1.6.3 ready.
1.0.1.0/24 via 192.0.2.10 on eth0 [the_rs 17:36:56 from 192.0.2.2] *
(100) [AS10i]
Type: BGP unicast univ
BGP.origin: IGP
BGP.as_path: 10
BGP.next_hop: 192.0.2.10
BGP.local_pref: 100
router id 192.0.2.2;
define rs_as = 999;
log "/var/log/bird.log" all;
log syslog all;
debug protocols { states, routes, filters, interfaces, events };
protocol device {};
table master sorted;
filter from_client {
bgp_ext_community.add((unknown 0x4300, 0, 1));
accept;
}
protocol bgp AS10 {
description "AS10";
local as 999;
neighbor 192.0.2.10 as 10;
rs client;
passive on;
ttl security off;
interpret communities off;
secondary;
import keep filtered on;
import filter from_client;
export all;
}
protocol bgp AS20 {
description "AS20";
local as 999;
neighbor 192.0.2.20 as 20;
rs client;
passive on;
ttl security off;
interpret communities off;
secondary;
import keep filtered on;
import filter from_client;
export all;
}
router id 192.0.2.2;
define rs_as = 999;
log "/var/log/bird.log" all;
log syslog all;
debug protocols { states, routes, filters, interfaces, events };
protocol device {};
ipv4 table master4 sorted;
ipv6 table master6 sorted;
filter from_client {
bgp_ext_community.add((unknown 0x4300, 0, 1));
accept;
}
protocol bgp AS10 {
description "AS10";
local as 999;
neighbor 192.0.2.10 as 10;
rs client;
passive on;
ttl security off;
interpret communities off;
ipv4 {
secondary;
import keep filtered on;
import filter from_client;
export all;
};
}
protocol bgp AS20 {
description "AS20";
local as 999;
neighbor 192.0.2.20 as 20;
rs client;
passive on;
ttl security off;
interpret communities off;
ipv4 {
secondary;
import keep filtered on;
import filter from_client;
export all;
};
}
