BGP Messages

[lagapidis (Lazarus Agapidis)]

Hello Narad

@narad

what is the total BGP messages Length are in Bytes Like open,Update,Notification and keep alive??

There is no predefined specific length of BGP messages except fo the maximum message length. You can find out more about that here:

https://notes.networklessons.com/bgp-maximum-message-size

@narad

Why the path attribute length is 0 in this below pic ??

The total path attribute length is a field in the update message of BGP. According to RFC4271, when this value is 0, it indicates that neither the Network Layer Reachability Information (NRLI) field nor the Path Attribute field is present in this update message.

@narad

When the neighbor gets down our we manually shut the peer which message is sent ??

When a BGP peer goes down, it can’t send any messages, because it has failed. That’s the definition of “going down”. In such a case, it is the lack of keepalives that causes the other end to realize that the peering has failed. Take a look at this lesson for more info:

BGP Neighbor Adjacency States

I hope this has been helpful!

Laz