03-12-2010 09:59 AM - edited 02-21-2020 04:32 PM
Trying to load balance 2 DMVPN tunnels from one remote router back to our headquarters site. The remote router is a 2811 running 12.4.24. It has two DSL connections and I have built two DMVPN tunnels back to my headquarters site with each tunnel going to a seperate router. I am running EIGRP across the WAN and LAN. Please see attached drawing.
When I set two equal default routes and simply let EIGRP do the balancing the router favors the 180.7.250.1 route and very little traffic goes across the 180.7.249.1 route.
The reason I am trying this is because this site is in kind of a remote area and I can only get a 500KB up and 1.5MB down DSL circuit. So to boost performance a little I wanted to try running two circuits.
I am open to any suggestions or hints on how to get a little more bandwidth to this site.
Thanks in advance.
Solved! Go to Solution.
03-15-2010 01:24 PM
EIGRP metrics are determined by Delay, Bandwidth, Reliability and Load. You have the same router, same tunnel interface. All interfaces involved in eigrp need to match exactly the same if you want to load balance across it. See how the composite metrics are different below. If you can make them match your traffic will load balance.
03-12-2010 10:43 AM
Hi,
DMVPN reply on routing for load balancing; is your hub site advertising out default route only? On your spoke router, you can configure offset-list under eigrp process to manipulate eigrp metric per prefix base. That way you can load balance the traffic leaving the spoke site, but you cannot control the return path on spoke router.
HTH,
Lei Tian
03-12-2010 11:17 AM
I've done this in the past by using bandwidth statements on your branch tunnel interefaces and adjusting the delay on the lan side of the router. I'd start by just using eigrp again and then issuing a "sh ip route" on your spoke routers. Does each spoke router just want to go over it's own tunnel or does it pass over to the local network from one of the spokes?
03-12-2010 11:58 AM
03-12-2010 12:21 PM
On the spoke I think you have a different eigrp group then you do on the two hubs. I'd try dropping the static routes and see if it's load balancing on the spoke. You should see something like this sh ip route 180.7.3.161
Heres the results from one of my routers running a GRE tunnel and using eigrp
Test# sh ip route 172.22.9.1
Routing entry for 172.22.9.0/24
Known via "eigrp 100", distance 90, metric 297246976, type internal
Redistributing via eigrp 100
Last update from 10.2.13.1 on Tunnel2, 06:30:32 ago
Routing Descriptor Blocks:
10.2.13.1, from 10.2.13.1, 06:30:32 ago, via Tunnel2
Route metric is 297246976, traffic share count is 1
Total delay is 500100 microseconds, minimum bandwidth is 9 Kbit
Reliability 255/255, minimum MTU 1006 bytes
Loading 56/255, Hops 1
* 10.1.13.1, from 10.1.13.1, 06:30:32 ago, via Tunnel1
Route metric is 297246976, traffic share count is 1
Total delay is 500100 microseconds, minimum bandwidth is 9 Kbit
Reliability 255/255, minimum MTU 1006 bytes
Loading 82/255, Hops 1
Test#
both tunnels have equal metrics and are load balancing
03-12-2010 12:34 PM
Yes, the EIGRP group on the spoke is a mis-type on my part. It should be 180 and I checked that it is 180 in the current running config. having said that I will try dropping the static routes and see what happens
03-15-2010 12:35 PM
Thanks for the help everyone, still not working right. Here is what I see when I remove all static routes. 180.7.2.220 is a FTP server , inside my network.
spoke#sho ip route 180.7.2.220
Routing entry for 180.7.2.0/24
Known via "eigrp 180", distance 90, metric 2818816, type internal
Redistributing via eigrp 180
Last update from 180.7.250.1 on Tunnel0, 07:47:43 ago
Routing Descriptor Blocks:
* 180.7.250.1, from 180.7.250.1, 07:47:43 ago, via Tunnel0
Route metric is 2818816, traffic share count is 1
Total delay is 10110 microseconds, minimum bandwidth is 1000 Kbit
Reliability 255/255, minimum MTU 1400 bytes
Loading 1/255, Hops 2
here is my eigrp config...........
router eigrp 1707
network 170.7.0.0
network 170.7.249.0 0.0.0.255
network 170.7.250.0 0.0.0.255
03-15-2010 01:02 PM
What are the results of "sh ip ei top all"
03-15-2010 01:12 PM
spoke#sho ip ei top 180.7.2.0/24
EIGRP-IPv4 Topology Entry for AS(180)/ID(180.7.250.3) for 180.7.2.0/24
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2818816
Descriptor Blocks:
180.7.250.1 (Tunnel0), from 180.7.250.1, Send flag is 0x0
Composite metric is (2818816/28416), route is Internal
Vector metric:
Minimum bandwidth is 1000 Kbit
Total delay is 10110 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1400
Hop count is 2
180.7.249.1 (Tunnel1), from 180.7.249.1, Send flag is 0x0
Composite metric is (2819072/28672), route is Internal
Vector metric:
Minimum bandwidth is 1000 Kbit
Total delay is 10120 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1400
Hop count is 3
03-15-2010 01:24 PM
EIGRP metrics are determined by Delay, Bandwidth, Reliability and Load. You have the same router, same tunnel interface. All interfaces involved in eigrp need to match exactly the same if you want to load balance across it. See how the composite metrics are different below. If you can make them match your traffic will load balance.
03-15-2010 01:31 PM
Thank you so much for your help, yes I see how the two routes differ, I am going to try some different
scenarios to try and make them equal.
Steve
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide