To: cisco-nsp@qual.net
cc: noc-backbone@forthnet.gr, vfyr@forthnet.gr
Subject: Load Balancing and Backup with OSPF
From: Vicky Fyrigou <vfyr@forthnet.gr>
Hello all,
We have tried to implement load balancing and backup, by using simply
ospf on two links. In fact, we had 2 links of 64kbps on two routers
with different networks on area 0. The links were of the same speed,
thus the ospf cost was the same and the test worked just fine.
Note that both interfaces had frame-relay encapsulation and we used
>>sub-interfaces for the connections. All sub-interfaces had ospf
network broadcast. We also used authentication for the area 0.
The problems started when we tried to use the same scenario with 2
lines of different speed: one of 64Kpbs and one of 128Kbps. I found
from Cisco FAQ that Ospf will only load share if the paths are the same
and that in order for Ospf to think that, you have to change the ospf
cost on the interfaces. So I did (once I changed the ospf cost to the
lowest speed -1562 on all interfaces and then I changed to the highest
speed- 800 on all interfaces).
The point is that load-sharing seemed to be working, but under full load
the interface with the highest bandwidth would only work up to 64Kbps!
What I could see from the ospf routes was that the traffic share count
was 1 for both interfaces.
Do you know whether there is a possibility to change somehow the traffic
share count for the interfaces, or any other way to make this work?
Thanks in advance,
Regards,
Vicky
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:13:13 EDT