BGP behavior on route-map

[Roel Reyes]

Hi all, 

It's strange what happen to my BGP router, 

i have route map set local preference to 110 applied on both of my Ustream so they would balance my outbound traffic, 

what happen is i tried to adjust my local preference on other ISP to a value of 150 and my BGP teared down, re-establish and prefix was reloaded again, why is that it applied automatically? 

i thought, it can only be applied after i reset BGP session or  do clear ip bgp soft in to prevent BGP tearing down. 

[Georg Pauwen]

Hello,

interesting. Do you have soft reconfiguration configured ? Can you post the configs of both ends ?

Also, check with 'show ip bgp neighbor x.x.x.x' if both ends support route refreshing, if they do, you should find a line like the one below:

Neighbor capabilities:
Route refresh: advertised and received(new)

That said, soft reconfig would take precedence...

[Roel Reyes]

Yes i have that configurations, 

Im not sure regarding the other side configurations since this is a live config.

This also happen during AS prepending to the other upstream, Route-map take effect immediately and more inbound traffic is received from this upstream as expected, BUT BGP was not tear down, 

I dont know if this is hardware issue, since im getting full routing table on my upstreams, and when i try to adjust local pref on route map, both of my upstream went down but immediately established its peering on both of them, Remember i haven't yet done "clear ip bgp neighbor x.x.x.x" to let the route map take effect 

Thanks Sir.