FW: router startup behavior

["Borchers, Mark" <mborchers () splitrock net>]

Forwarded to the list:

-----Original Message-----
Subject: RE: router startup behavior

On Tue, 15 Jan 2002, Borchers, Mark wrote:

Mark, I don't have nanog post so, if you could pass this along for me, I
believe that it may be "obvious" advice and it seems that the obvious is
what escapes us most often.

> Yeah, (c) seems most likely to me.  Ratul, a script like
> this or some variant could cause what you are seeing:
>
> config-router#  no neighbor <a>
> config-router#  no neighbor <b>  
> config-router#  no neighbor <c>
> (script to rewrite filters executes)
> config-router#  neighbor <a> remote-as <x>
> config-router#  neighbor <b> remote-as <y>
> config-router#  neighbor <c> remote-as <z>
> (sessions start coming up)
> config-router#  neighbor <a> route-map <A> out
> config-router#  neighbor <b> route-map <B> out
> config-router#  neighbor <c> route-map <C> out
> config-router#  Ctrl-Z
> # clear ip bgp external soft out
>
> Just guessing - you're seeing these events between midnight 
> and 5 am?

Wouldn't it be wiser to do the following:

config-router# no neighbor <a>
config-router# no neighbor <b>
config-router# no neighbor <b>
 (script to rewrite filters executes)
config-router# neighbor <a> remote-as <x>
config-router# neighbor <a> shutdown
config-router# neighbor <b> remote-as <y>
config-router# neighbor <b> shutdown
config-router# neighbor <c> remote-as <z>
config-router# neighbor <c> shutdown
config-router#  neighbor <a> route-map <A> out
config-router#  neighbor <b> route-map <B> out
config-router#  neighbor <c> route-map <C> out
config-router# no neighbor <a> shutdown
config-router# no neighbor <b> shutdown
config-router# no neighbor <c> shutdown
config-router#  Ctrl-Z
# clear ip bgp external soft out

This way, the neighbor has much less time to come up without filters since
we're immediately putting it in admin idle after naming it.

---
John Fraizer
EnterZone, Inc