bgp keepalive and expired issues on bird 1.6.8

[Troy Beisigl]

안녕하세요 Ted,

Not sure if this applies to bird as we have not had this issue with it, but we did see this with our Cisco ASR9k peering with a carrier that uses Nokia routers. This issue was that the protocol is supposed to negotiate the keepalive values so that the lowest value between them takes precedent. The issue is that the Nokia routers negotiate it and then ignore it. We had to match the keepalives with what that carrier had set in their routers. 

Hope that this may help with the same issue in bird. 

Best,

-Troy 

Sent from my iPhone

> On Sep 27, 2022, at 8:30 PM, 안상혁 via Bird-users <bird-users at network.cz> wrote:
> 
> 
> Hello,
> 
> we have encountered some issues using bird 1.6.8
> 
> there are two issues :
> 
> 1) sometimes bird looks like doesn't handle neighbor's bgp keepalive messages.
> 
> when we get bgp hold timer exprired issue,
> on tcpdump there are keepalive packets that neighbor physical router sent and the server replied.
> 
> but there is no "Got KEEPALIVE" messages on bird.log and bgp session closed after "Error: Hold timer expired" message.
> 
> 2) bgp session exprired less than bgp hold timer value.
> 
> we set BGP hold timer to 9 seconds, but bgp expired in 7 seconds
> 
> In logs got it:
> 
> 2022-08-28 10:25:55 <TRACE> as1: Got KEEPALIVE
> 
>   <- 10:25:56 ( got keepalived from as1 neighbor on tcpdump but not on bird.log )
>   <- 10:25:59 ( got keepalived from as1 neighbor on tcpdump but not on bird.log )
>  
> 2022-08-28 10:26:02 <RMT> as1: Error: Hold timer expired
> 2022-08-28 10:26:02 <TRACE> as1: BGP session closed
> 
> 
> 
> bgp neighbor is physical router.
> 
> have you got reported this cases?
> or we should upgrade to bird 2?
> 
> Thank you and best regards,
> ted