[c-nsp] 6506 unusual behavior

Arie Vayner (avayner) avayner at cisco.com
Wed Aug 27 13:06:20 EDT 2008


Adam,

One thing to consider is to reduce the BGP view.
Do they really need the full view, or can actually take a partial view
from each provider (for example each providers originated networks, and
maybe their direct customers), and then use a default route for the rest
of the Internet (the best alternative is to actually ask the providers
to advertise a default route).

I most stub (as in non transit) ASs this should be a valid solution.

Another alternative could be to introduce another set of border routers,
such as 7201 routers. 7201 is a 7200/NPE-G2 in 1RU form factor with
4x1GE ports.
It can easily take a full BGP view, but traffic sizing should be
performed so that we can actually handle the load.
Actually, I am not sure if the upgrade to Sup720-3BXL would be much more
expansive than the 7201, but I suggest you explore these options with
your customer.

Arie

-----Original Message-----
From: Adam Korab [mailto:adam.korab at gmail.com] 
Sent: Wednesday, August 27, 2008 19:56 PM
To: Arie Vayner (avayner)
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] 6506 unusual behavior

On Wed, Aug 27, 2008 at 11:15 AM, Arie Vayner (avayner)
<avayner at cisco.com> wrote:
> Adam,

Hi Arie,

> I think you have a bit too many routes on this box...

Probably...sup2 is kind of old.

> Can you please share the outputs of:
>
> - show ip route summary

edge1#sh ip ro sum
IP routing table name is Default-IP-Routing-Table(0)
Route Source    Networks    Subnets     Overhead    Memory (bytes)
connected       0           5           400         800
static          0           2           224         320
ospf <removed> 0           123         8064        19680
  Intra-area: 5 Inter-area: 0 External-1: 0 External-2: 118
  NSSA External-1: 0 NSSA External-2: 0
bgp <removed>       130413      130722      16712640    41818320
  External: 5090 Internal: 256045 Local: 0
internal        2642                                3117560
Total           133055      130852      16721328    44956680
Removing Queue Size 0

> - show mls cef summary

edge1#sh mls cef sum

Total CEF switched packets:  0000000825744817
Total CEF switched bytes:    0000440372791097
Total routes:                261292
    IP unicast routes:       261292
    IPX routes:              0
    IP multicast routes:     0

> - show mls cef maximum-routes

edge1#sh mls cef maximum-routes
                   ^
% Invalid input detected at '^' marker.

So if that is indeed the case and this box has 261k routes while
supporting 192k...what can be done to mitigate it?  I don't believe the
end customer has the budget to upgrade to sup720-3bxl.  It's a pair of
6506s, each with an upstream provider; each box is taking full views and
they iBGP peer with each other.

Thanks!

--Adam


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