[c-nsp] BGP load balancing with dCEF

[Ihsan Junaidi Ibrahim]

This is getting weird, suddenly i'm getting cef not running messages:

rtr-2#sh ip cef 202.75.134.1
%CEF not running
%Prefix not found

any clues on how I should treat this symptom? reload the router?

On 10/10/06, Oliver Boehmer (oboehmer) <oboehmer at cisco.com> wrote:
> Hi,
>
> thanks for the info.. In your case, you're doing ebgp-multihop with
> equal-cost statics over the links, so no need to enable maximum-paths,
> you're right. It should work.
> Can you check "show ip cef 202.75.130.4 internal" and check the
> adjacencies of the 16 hash buckets? You should see all the interfaces.
>
>         oli
>
> Ihsan Junaidi Ibrahim <mailto:ihsan.junaidi at gmail.com> wrote on Tuesday,
> October 10, 2006 1:31 PM:
>
> > Previously BGP maximum-path is not enabled but I've enabled that just
> > before I took the configuration snapshot. My understanding is that
> > multipath is only used for peers connected via multiple routers which
> > is not the case here.
> >
> > On 10/10/06, Ihsan Junaidi Ibrahim <ihsan.junaidi at gmail.com> wrote:
> >> 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
> >>
> >
> >
> > --
> > Thank you for your time,
> > Ihsan Junaidi Ibrahim
>


-- 
Thank you for your time,
Ihsan Junaidi Ibrahim