[c-nsp] BGP load balancing with dCEF

[Ihsan Junaidi Ibrahim]

Hi,

The peer interfaces are all located on the same router and so do us.
It's an eBGP peering. and the problem is that traffic always flow
heaviest on the fourth interface. Most of the time, the first 3 links
are idle.

Here's the required output:
---
rtr-2#sh ip bgp 202.75.130.4
BGP routing table entry for 202.75.128.0/19, version 48155320
Paths: (3 available, best #2)
  Advertised to peer-groups:
     ibgp-neighbor
  6453 9534, (received & used)
    216.6.121.9 from 216.6.121.9 (66.110.0.81)
      Origin IGP, localpref 100, valid, external
  9534, (received & used)
    202.75.134.1 from 202.75.134.1 (202.75.134.1)
      Origin IGP, metric 0, localpref 100, valid, external, best
  2914 9534, (received & used)
    203.78.193.57 from 203.78.193.57 (203.78.192.1)
      Origin IGP, metric 0, localpref 100, valid, external
      Community: 190972314 190974311 190975304
---

rtr-2#sh ip route 202.75.130.4
Routing entry for 202.75.128.0/19, supernet
  Known via "bgp 9930", distance 20, metric 0
  Tag 9534, type external
  Last update from 202.75.134.1 00:08:35 ago
  Routing Descriptor Blocks:
  * 202.75.134.1, from 202.75.134.1, 00:08:35 ago
      Route metric is 0, traffic share count is 1
      AS Hops 1, BGP network version 48155320
---

rtr-2#sh ip route 202.75.134.1
Routing entry for 202.75.134.1/32
  Known via "static", distance 1, metric 0
  Tag 1
  Redistributing via ospf 100, bgp 9930
  Advertised by bgp 9930
  Routing Descriptor Blocks:
    203.121.99.2
      Route metric is 0, traffic share count is 1
    203.121.99.6
      Route metric is 0, traffic share count is 1
    203.121.99.10
      Route metric is 0, traffic share count is 1
  * 203.121.99.14
      Route metric is 0, traffic share count is 1

On 10/10/06, Oliver Boehmer (oboehmer) <oboehmer at cisco.com> wrote:
> cisco-nsp-bounces at puck.nether.net <> wrote on :
>
> > Hi all,
> >
> > We're having trouble doing per-destination load balancing on outgoing
> > BGP traffic over 4 x E1 links. It's a 7507 (12.0(26)S) with dCEF
> > enabled (globally and on the interfaces). Whenever I do a show ip cef
> > xxx.xx, there's only 1 next-hop entry instead of 4. How do I get all 4
> > next-hop entries to be installed?
>
> Are you installing multiple BGP paths into your RIB, i.e. did you
> specify "maximum-paths 4" in your BGP config, or how is your setup?
> Please show a "show ip bgp <prefix>", "show ip route <bgp-prefix>" and
> "show ip route <bgp-next-hop-of-this-prefix>".
>
>         ol
>


-- 
Thank you for your time,
Ihsan Junaidi Ibrahim