[c-nsp] Unintentional load balancing of traffic

[Daniel Dib]

-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
CiscoNSP List
Sent: den 18 september 2015 01:58
To: cisco-nsp at puck.nether.net
Subject: [c-nsp] Unintentional load balancing of traffic

Hi Everyone,


Have a PE that has 2 "interpop" connections back to 2 other PE's...both
links running ospf+mpls.


Link 1 (primary) has ip ospf cost 201

Link 2 (secondary has ip ospf cost 202



But traffic egressing from this PE is load balancing(per session) across the
2 links?



If I do a sh ip route foo, it displays both paths, known via OSPF and route
metric of 205?



Hoping someone can explain why? (Are the ospf costs too close, and "other"
attributes/metrics come into play, and the links are seen as equal?)



Cheers.

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Please give us a show ip route x.x.x.x and show ip ospf data x.x.x.x so that
we can analyse the routing.

How is your OSPF setup? Is each POP in its own area or are you running
everything in area 0?

Daniel
Senior Network Architect
CCIE #37149