BGP Resets

The_guroo_2 · ‎07-11-2007

Guys just a quick question........when we do soft reset an dwhen we do hard rest....lik ein have som escenario.....if we advertise a new network then we have to do reset or whenever we or add prefix list we will do resets.....the first question is when we do reset in bgp an dthe second is when we do hard and when we do soft.....really cant get my head around it

Jon Marshall · ‎07-11-2007

Hi

From the BGP FAQ

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Q. When and how should I reset a BGP session?

A. Clear a BGP session when you change the inbound/outbound policy for this session. Issue the clear ip bgp x.x.x.x soft out command to clear a BGP session in order to bring outbound policy changes into effect. Issue the clear ip bgp x.x.x.x command in order to clear a BGP session to bring inbound policy changes into effect. If the neighbor has the soft reconfiguration capability, you can issue the clear ip bgp x.x.x.x soft in command.

Note: With Cisco IOS Software Release 12.0 and later, a new BGP Soft Reset Enhancement feature is introduced. Refer to BGP Soft Reset Enhancement for more information.

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So if you make a change at your end you can do a soft reset.

If a change is made at the other end you may need to do a full reset which obviously means an interruption in service or you may be able to do a soft in reset depending on the neighbour capabilities.

HTH

Jon

UTVi-NetAdmin · ‎06-02-2008

Hi Jon,

I realise this post is old but I'll try any way.

I am having difficulty finding out the capabilities of a remote, external BGP router. What part of the output of the following confirms both routers are capable of route refresh?

Thanks,

Mark

router#sh ip bgp neighbors AAA.BBB.CCC.DDD

BGP neighbor is AAA.BBB.CCC.DDD+1, remote AS 1, external link

BGP version 4, remote router ID AAA.BBB.CCC.DDD

BGP state = Established, up for 9w2d

Last read 00:00:10, hold time is 180, keepalive interval is 60 seconds

Neighbor capabilities:

Route refresh: advertised and received(old & new)

Address family BGP IPv4: advertised and received

Message statistics:

InQ depth is 0

OutQ depth is 0

Sent Rcvd

Opens: 47 44

Notifications: 23 21

Updates: 0 15611157

Keepalives: 411956 411852

Route Refresh: 0 0

Total: 412072 16023101

Default minimum time between advertisement runs is 30 seconds

For address family: BGP IPv4

<...output ommitted...>

Jon Marshall · ‎06-02-2008

"Route refresh: advertised and received(old & new)"

The above line tells you that this router and the peer router can both support route refresh.

Jon