OSPF Equal Cost (multiple links) but unbalanced traffic

[asakurahao]

Hi!

I would like to ask about OSPF.

We are using 4 links running OSPF point to point with equal cost to load balance MPLS L2 traffic between our two routers.

And from what we are experiencing right now is that it didnt balance the load the way it should have.

The first link always catches up the bulk of the traffic, while the remaining 3 links load balances, I would like to inquire on steps to mitigate the issue.

Appreciate if I could receive some help to solve the issue

Thank you very much  in advance!

Best Regards,

asakurahao

[Peter Paluch]

Hello Jayson,

load balance MPLS L2 traffic between our two routers

Can you please elaborate on this? What exactly do you mean by this statement? I am asking because equal-cost routes installed by OSPF will primarily load-balance pure IP traffic. Load balancing MPLS traffic is more intricate. Perhaps a depiction of your network topology would be helpful.

Best regards,

Peter

[asakurahao]

Hi Sir Peter,

Sorry for the confusion, allow me to send a copy of a sample topology depicting our scenario later (ill just need to finish the diagram).

The 4 links I mentioned are 4 point to point ospf links with equal cost to load balance but unfortunately one of the links carries a higher share of traffic compared to the 3 other links.

The said 4 point to point parallel links are used to transport MPLS traffic.

thanks!

[arunkv1980]

I do have almost the same problem.

i have 2 x 20 Mbps Point to Point ethernet links configured with equal ospf cost and both links terminated on the single router at both ends.

interface FastEthernet0/0/0

 bandwidth 20000
 ip address x.x.x.x y.y.y.y
 load-interval 30
 duplex auto
 speed auto
 traffic-shape rate 20000000 500000 500000 1000
!
interface FastEthernet0/0/1
 bandwidth 20000
 ip address x.x.x.x y.y.y.y
 load-interval 30
 duplex auto
 speed auto
 traffic-shape rate 20000000 500000 500000 1000

FastEthernet0/0/0 is up, line protocol is up
  Internet Address 135.254.193.53/30, Area 0.0.0.1
  Process ID 3435, Router ID 135.254.0.95, Network Type BROADCAST, Cost: 5

FastEthernet0/0/1 is up, line protocol is up
  Internet Address 135.254.193.45/30, Area 0.0.0.1
  Process ID 3435, Router ID 135.254.0.95, Network Type BROADCAST, Cost: 5

I see majority of the traffic using the link F0/0/0 and only 30% traffic using the second link F0/0/1.

I used per-packet load-sharing on these interfaces which caused throughput problems, so i removed that from the interface. Should i add some CEF commands or should try per-destination load sharing to see equal traffic on both links ?