[c-nsp] Cisco ME3600X MPLS OSPF balanced LSP, non LSP drop packets

[Dan Peachey]

On 15 September 2015 at 14:18, Brett . <brett8192 at hotmail.com> wrote:

> My network has deployed mpls on ciscos on a trial basis on only a small
> subsection of our network.
>
> I have a cisco tac case opened for the situation where Cisco ME3600X has
> balanced path and is dropping traffic.
> - in the balanced path One path is a label switched path and the other is
> non label switched.
>
> Traffic is dropped by the ME3600X when trying to push a packet it received
> with a label out the non label switched path.
>
> It only impacts traffic it receives traffic with a label, it does not
> impact traffic the router generates.
>
> this impacts all the IOSs available for the ME3600X.
>
> ME3600X-2#sho ip route 5.5.5.5
> Routing entry for 5.5.5.5/32
>   Known via "ospf 100", distance 110, metric 20
>   Tag 66000, type extern 2, forward metric 11
>   Last update from 10.200.3.3 on Vlan2003, 2d15h ago
>   Routing Descriptor Blocks:
>   * 10.200.4.4, from 5.5.5.5, 1w6d ago, via Vlan2004
>       Route metric is 20, traffic share count is 1
>       Route tag 66000
>     10.200.3.3, from 5.5.5.5, 2d15h ago, via Vlan2003
>       Route metric is 20, traffic share count is 1
>       Route tag 66000
>
> ME3600X-2#show mpls forwarding-table 5.5.5.5
> Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
> Label      Label      or Tunnel Id     Switched      interface
> 21         20         5.5.5.5/32       0             Vl2003     10.200.3.3
>            No Label   5.5.5.5/32       0             Vl2004
>  10.200.4.4 << traffic would be dropped when this path chosen
>
>
>
Out of interest, what happens if you shut down Vl2003? Does traffic get
forwarded via Vl2004? So, without ECMP, does traffic get forwarded?

Cheers,

Dan