[c-nsp] MPLS VPN Problem - EoS conflict

[Oliver Boehmer (oboehmer)]

Ibrahim Abo Zaid <> wrote on Tuesday, December 23, 2008 11:23:

> Hi All
> 
> 
> I was implementing MPLS VPN topology and by mistake i was configuring
> PE-LP used for MP-BGP peering with a worng mask /24 instead of /32
> (remote PE-LP mask is /32) .
> 
> by T.S , i discovered that P router upstream of this PE was dropping
> incoming MPLS packets with the below error message
> 
> tagsw_replace_header: Pkt drop -- EoS conflict, incg label 18 hwinput
> Fa0/0 
> 
> discovering FIB
> 
> 3#sh mpls forwarding-table | in 18
> 
> 18     Untagged    150.1.3.3/32      1230       Se0/1      point2point
> 
> so when the mask was /24 , PE advertise label as untag label so
> incoming traffic over MPLS interface will be conveted to IP traffic
> and looking up in LFIB , it will forward it down MPLS interface to PE
> as native IP packet while it should MPLS packet with label-3

Hmm, the above LFIB shows /32, but you said you configured it as /24?
Are you running OSPF? I guess this would explain it: OSPF advertises
loopbacks with a /32, so remote routers installed the /32, but the local
router installed the connected route with a /24 and advertised an
imp-null for it. No LIB entry existed for the /32, hence the
"untagged"..

	oli