Not able to configure bgp with BIRD

[Ondrej Zajicek]

On Fri, Apr 23, 2021 at 09:52:15AM +0530, Dhruv Bhagadia wrote:
> Hi all,
> 
> I was trying to configure bgp using BIRD on a server running rhel 7.6. The
> issue I am facing is that the neighbor AS seems to be rejecting the routes
> sent by my local AS. However, my server seems to be learning routes sent by
> the neighbor AS router. Have provided some details from the logs below. I
> wanted to ask what could be the probable reason that the remote is
> rejecting the packets?
> 
> 2021-04-22 17:48:56 <TRACE> bgp1 > added [best] 172.19.1.192/28 via
> 10.33.5.33 on enp26s0d1
> 2021-04-22 17:48:56 <TRACE> bgp1 < rejected by protocol
> 172.19.1.192/28 via 10.33.5.33 on enp26s0d1
> 2021-04-22 17:48:56 <TRACE> bgp1 > added [best] 172.19.1.200/30 via
> 10.33.5.33 on enp26s0d1
> 2021-04-22 17:48:56 <TRACE> bgp1 < rejected by protocol

Hi

This is just a confusing log that say a route received from the peer
(e.g. 172.19.1.192/28) is not sent back to the peer.


> In consequence to this, BIRD throws an error after sometime saying `*bgp1:
> Error: Hold timer expired *` and `bgp1: Received: Hold timer expired`

That is probably unrelated.


> However from the logs I figured out that the difference between most latest
> KEEPALIVE message and the error being thrown is 2 secs. Since I have set
> HOLD time to 180 sec in config shouldn't this error be never thrown since
> the KEEPALIVE message will reset it? Sharing that logs too below

Hold time is negotiated as min of local and remote hold time. So perhaps
remote side has too short hold time (that would make why it sends
keepalives so often)? You can see real hold time in 'show protocols all'.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."