[c-nsp] bgp slow prefix learning

[Jason LeBlanc]

I know one end is Cisco, a 7600/Sup720, no idea what code.  The other 
end I have no clue.  I added the mtu, no change as of yet.  In 2.5 hrs 
I've gotten 1087 prefixes on one, in 1 hr I've gotten 631 on the other.  
I've never seen this move so slowly.

Jared Mauch wrote:
> On Tue, Aug 21, 2007 at 12:42:14PM -0400, Jason LeBlanc wrote:
>   
>> I'm wondering if I have something that is by design or if something else 
>> is slowing my routers down.  I have two 2811s with 768 megs running 
>> 12.4(4)T3, each connected to different upstreams via fast ethernet.  I'm 
>> using prefix lists to limit them to /22, but I should have enough ram 
>> for a full /24 view.  My problem is that anytime I clear a neighbor it 
>> takes them hours to learn all the prefixes again, which has forced me to 
>> add static defaults to compensate.  My cpu is 2-4% during this, so I 
>> can't see how its cpu bound.  Anyone have any ideas?
>>     
>
> 	Enable "ip tcp path-mtu-discovery" globally.
>
> 	that should help.  If they're also using a Juniper,
> some much older code had some odd propogation properties.  They
> may need to upgrade code.  I think this was back in 4.x or 5.x.
>
> 	- Jared
>
>