Tuesday, March 30, 2021

Dell OS10 - BGP Idle Issue?

Hello,

I'm running Dell OS10 firmware 10.5.2.3 on some Dell S5248F-ON switches and currently experiencing a weird issue with BGP sessions staying in an IDLE state and I was wondering if anyone else has experienced this same behaviour before?

When the neighbouring BGP peer's interface flaps or we perform a manual shutdown/no shutdown on the interface or the server is rebooted; the BGP session obviously goes down, although, it will constantly stay in an "IDLE" state on my switch and will never attempt to establish a connection.

A packet capture shows the peer initiate/establish the TCP handshake and sends its initial OPEN message but we respond with an RST packet which is expected if our BGP state is stuck in IDLE.

It's definitely not a Layer 1-3 issue since ARP/ping is working perfectly fine without any problems and we have routes to the BGP peer. Control plane ACLs are fine as well with the traffic permitted.

Performing a shutdown/no shutdown or a "clear ip bgp x.x.x.x" on the neighbour on the OS10 switch still does not resolve the problem and the neighbour remains in an IDLE state.

It's only when I delete and re-configure the BGP neighbour again does it resolve the problem and we can bring the BGP peer online. Although, if the BGP peer was to go down again it would remain in IDLE.

I am going to raise a case with Dell but any help would be appreciated if you've ran into this problem before :)



No comments:

Post a Comment