BGP Soft-Reconfiguration command not found

[ShaikatAhmed99]

Hi,

I am facing a problem. Would appreciate to have suggestions. 

When I am trying to write the command "neighbour ***** soft-reconfiguration inbound" in ASR 1000, it is not taking the command, Searched for suggestion but not showing any command like this. I am confused here.

Thank you.

[Peter Paluch]

Hello,

It is possible that you are using the address-family style of BGP configuration. There, the general configuration of a neighbor is at the router bgp level but a per-AF behavior, including the soft reconfiguration, has to be enabled in the address family section, like this:

router bgp 1
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 192.0.2.1 remote-as 2
 !
 address-family ipv4
  neighbor 192.0.2.1 activate
  neighbor 192.0.2.1 soft-reconfiguration inbound
 exit-address-family

Can you try this out?

Best regards,
Peter

[Georg Pauwen]

Hello,

make sure you got the syntax right:

neighbor x.x.x.x soft-reconfiguration inbound

not

neighbour

[paul driver]

Hello
Just like to add, The rtrs should also be able to support the bgp route-refresh capability which would enable you soft reset for NLRI updates as such soft reconfiguration wouldnt really be required and is a older way of storing unfiltered/edited copy’s of bgp routes which is actually more resource intensive to the rtr.  

You could way to check if your rtrs supports RR by:
sh ip bgp neighbors x.x.x. | s neighbor capabilities

[Peter Paluch]

Hi Paul,

100% agree. In my experience, every BGP implementation I've worked with already supports the RFC 2918 Route Refresh, and it's on by default.

This being said, it seems that quite a few customers want to keep using Soft Reconfig as a diagnostic tool - to see what routes came from the neighbor in the first place, even before they're subject to inbound routing policies. From this point of view, I have to admit that the Soft Reconfig is a very useful diagnostic and troubleshooting tool. But exactly as you pointed out, it comes at a price of a higher memory footprint which may be, depending on the amount of routes to store, quite significant.

Best regards,
Peter

[MHM Cisco World]

I think ASR has different than IOS, 

under neighbor config soft.

[Peter Paluch]

Hello,

Perhaps you mean ASR9000 series that runs IOS-XR. However, the original poster mentioned ASR1000 which is definitely running IOS-XE.

Best regards,
Peter