Hi!
I'm running bird 2.15.1 and I'm trying to make it talk to cilium that uses
gobgp under the hood. I can negotiate the session over ipv4 with no issues,
but due to a bug in the cilium implementation, the ipv6 routes aren't
advertised properly. The suggestion from cilium was to negotiate the
session over ipv6, but this creates issues for bird.
I have a config that looks somewhat like this:
protocol bgp {
local port 179 as 65100;
neighbor range 0::/0 port 179 as 65100 internal;
dynamic name "GW6_";
direct;
passive;
ipv4 {
import all;
};
ipv6 {
import all;
};
}
protocol bgp {
local port 179 as 65100;
neighbor range 10.0.0.0/8 port 179 as 65100 internal;
dynamic name "GW4_";
direct;
passive;
ipv4 {
import all;
};
ipv6 {
import all;
};
}
When I connect to bird over ipv4, gobgp sends a packet like this:
Frame 4: 154 bytes on wire (1232 bits), 154 bytes captured (1232 bits) on
interface vmbrdev, id 0
Ethernet II, Src: 22:fc:7f:47:6b:f4 (22:fc:7f:47:6b:f4), Dst:
6e:82:6c:1b:e9:95 (6e:82:6c:1b:e9:95)
Internet Protocol Version 4, Src: 10.224.129.15, Dst: 10.224.129.1
Transmission Control Protocol, Src Port: 39201, Dst Port: 179, Seq: 1, Ack:
1, Len: 88
Border Gateway Protocol - OPEN Message
Marker: ffffffffffffffffffffffffffffffff
Length: 88
Type: OPEN Message (1)
Version: 4
My AS: 65100
Hold Time: 90
BGP Identifier: 10.224.129.15
Optional Parameters Length: 59
Optional Parameters
Optional Parameter: Capability
Parameter Type: Capability (2)
Parameter Length: 57
Capability: Route refresh capability
Type: Route refresh capability (2)
Length: 0
Capability: FQDN Capability
Type: FQDN Capability (73)
Length: 12
Hostname Length: 10
Hostname: dev-master
Domain Name Length: 0
Domain Name:
Capability: Unknown capability 75
Type: Unknown (75)
Length: 13
Unknown: 0c476f4247502f332e32332e30
Capability: Multiprotocol extensions capability
Type: Multiprotocol extensions capability (1)
Length: 4
AFI: IPv4 (1)
Reserved: 00
SAFI: Unicast (1)
Capability: Multiprotocol extensions capability
Type: Multiprotocol extensions capability (1)
Length: 4
AFI: IPv6 (2)
Reserved: 00
SAFI: Unicast (1)
Capability: Support for 4-octet AS number capability
Type: Support for 4-octet AS number capability (65)
Length: 4
AS Number: 65100
Capability: Extended Next Hop Encoding
Type: Extended Next Hop Encoding (5)
Length: 6
AFI: IPv4 (1)
SAFI: Unicast (1)
Next hop AFI: IPv6 (2)
Which is followed up by OPEN from bird2 and they establish the session. The
logs say:
May 04 14:47:02 ammy bird[7755]: bgp2: Incoming connection from
10.224.129.15 (port 39201) accepted
May 04 14:47:02 ammy bird[7755]: GW4_1: Initializing
May 04 14:47:02 ammy bird[7755]: GW4_1: Starting
May 04 14:47:02 ammy bird[7755]: GW4_1: State changed to start
May 04 14:47:02 ammy bird[7755]: GW4_1: Started
May 04 14:47:02 ammy bird[7755]: GW4_1: Got
OPEN(as=65100,hold=90,id=10.224.129.15)
May 04 14:47:02 ammy bird[7755]: GW4_1: Sending
OPEN(ver=4,as=65100,hold=240,id=0ae08101)
May 04 14:47:02 ammy bird[7755]: GW4_1: Sending KEEPALIVE
May 04 14:47:02 ammy bird[7755]: GW4_1: Got KEEPALIVE
May 04 14:47:02 ammy bird[7755]: GW4_1: BGP session established
When I try to establish the connection over ipv6, gobgp sends an OPEN
that's exactly the same sans being transferred over ipv6:
Frame 15: 174 bytes on wire (1392 bits), 174 bytes captured (1392 bits) on
interface vmbrdev, id 0
Ethernet II, Src: 22:fc:7f:47:6b:f4 (22:fc:7f:47:6b:f4), Dst:
6e:82:6c:1b:e9:95 (6e:82:6c:1b:e9:95)
Internet Protocol Version 6, Src: 2a01:xxx:xxx:xxx:xxx:xxx:xxx:d930, Dst:
fd00::53
Transmission Control Protocol, Src Port: 58663, Dst Port: 179, Seq: 1, Ack:
1, Len: 88
and then bird just stalls the connection. The logs say:
May 04 14:49:17 ammy bird[7755]: bgp1: Incoming connection from
2a01:4f8:173:fe11:6f81:e7cd:2787:fb71 (port 35581) accepted
May 04 14:49:17 ammy bird[7755]: GW6_1: Initializing
May 04 14:49:17 ammy bird[7755]: GW6_1: Starting
May 04 14:49:17 ammy bird[7755]: GW6_1: State changed to start
May 04 14:49:17 ammy bird[7755]: GW6_1: Waiting for
2a01:xxx:xxx:xxx:xxx:xxx:xxx:d930 to become my neighbor
I suspect it's either a bug or a misconfiguration on the bird side, because
gobgp behaves the same in both scenarios. How do I investigate/debug this
further?
