I'm setting up a session with an external BGP peer over IPv4. The peer is in passive mode and We should initiate BGP session from our side. It appears that VyOS does not send OPEN messages even though we are not in passive mode. The session is never gets established. During a troubleshooting session, our peer temporarily removed passive mode on their end and session came up instantly.
The identical setup for IPv6 session works fine.
**This is absolutely critical issue!!!**
```
Version: VyOS 1.3-rolling-202104280642
Release Train: equuleus
Built by:
[email protected]
Built on: Thu 29 Apr 2021 03:42 UTC
Build UUID: ae16ca93-defa-4a35-8a20-f48a77d41752
Build Commit ID: 470b2d00790a82
Architecture: x86_64
Boot via: installed image
System type: KVM guest
Hardware vendor: QEMU
Hardware model: Standard PC (Q35 + ICH9, 2009)
Hardware S/N:
Hardware UUID: 4e4038df-97f2-4dea-8a4b-c44a3f0ff46a
Copyright: VyOS maintainers and contributors
```
relevant config
```
r6# show protocols bgp | strip-private
bgp XXXXXX {
address-family {
ipv4-unicast {
network xxx.xxx.128.0/24 {
}
}
ipv6-unicast {
network xxxx:xxxx:6000::/48 {
}
}
}
neighbor xxx.xxx.195.1 {
address-family {
ipv4-unicast {
route-map {
import NO-EXPORT
}
soft-reconfiguration {
inbound
}
}
}
ebgp-multihop 3
remote-as XXXXXX
update-source eth0
}
neighbor xxxx:xxxx:2700:3::1 {
address-family {
ipv6-unicast {
route-map {
import NO-EXPORT
}
soft-reconfiguration {
inbound
}
}
}
ebgp-multihop 3
remote-as XXXXXX
update-source eth0
}
parameters {
default {
no-ipv4-unicast
}
router-id xxx.xxx.128.100
}
}
```
This is output of `show ip bgp neighbors...` command:
```
BGP neighbor is xxx.xxx.195.1, remote AS 40676, local AS 396142, external link
BGP version 4, remote router ID xxx.xxx.0.0, local router ID xxx.xxx.128.100
BGP state = Connect
Last read xxxx:xxxx:46, Last write never
Hold time is 180, keepalive interval is 60 seconds
Message statistics:
Inq depth is 0
Outq depth is 0
Sent Rcvd
Opens: 0 0
Notifications: 0 0
Updates: 0 0
Keepalives: 0 0
Route Refresh: 0 0
Capability: 0 0
Total: 0 0
Minimum time between advertisement runs is 0 seconds
Update source is xxx.xxx.193.59
For address family: IPv4 Unicast
Not part of any update group
Inbound soft reconfiguration allowed
Community attribute sent to this neighbor(all)
Inbound path policy configured
Route map for incoming advertisements is *NO-EXPORT
0 accepted prefixes
Connections established 0; dropped 0
Last reset xxxx:xxxx:46, Waiting for peer OPEN
External BGP neighbor may be up to 3 hops away.
BGP Connect Retry Timer in Seconds: 120
Next connect timer due in 15 seconds
Read thread: off Write thread: off FD used: 27
```