bird2 doesn't negotiate with gobgp over ipv6
Maria Matejka
maria.matejka at nic.cz
Sun May 5 08:35:43 CEST 2024
Then i was totally wrong with that, sorry.
Now i checked once again the log, and there are actually two different neighbor addresses, one ending :fb71, another :d930. This may be some discrepancy in your ipv6 settings.
The error message actually means "you requested direct connection but i can't see the right interface to use because there is no interface with this range assigned".
Maria
On 4 May 2024 17:59:21 CEST, Vladimir Pouzanov <farcaller at gmail.com> wrote:
>I actually started with my /64 and then expanded to ::/0 to the same result.
>
>On Sat 4 May 2024 at 16:54, Maria Matejka <maria.matejka at nic.cz> wrote:
>
>> Not at my computer, just a wild guess – would you try please, instead of
>> ::/0, narrowing the range, e.g. like 2000::/3? I haven't seen the code
>> recently but this may help.
>>
>> Maria
>>
>>
>> On 4 May 2024 17:16:21 CEST, Vladimir Pouzanov <farcaller at gmail.com>
>> wrote:
>>
>>> 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?
>>>
>> --
>> Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
>>
--
Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
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