Solved: successor and feasible successor to remote-routers

rizwanr74 · ‎12-04-2009

Hi there,

Can someone tell me, how to influence two equal cost load-balancing routers (i.e. 6500 switches) to become successor and feasible successor to remote-routers. Right now, I have two 6500 switches connected to our provider’s cloud, in which case all routes are being advertised from both 6500 switches (routes local to both 6500 switches). in which case neighboring routers doing load-balancing as these routes with equal cost, due to only one 6500 switch has WAAS connected, I do not want EIGRP doing equal cost load- balancing.

I have one interface from both 6500 switch connected to provider’s cloud switch.

thanks in advance.

Jon Marshall · ‎12-05-2009

rizwanr74 wrote:

Thanks Reza,

I am familiar with changing the metric value but the question is on which interface?

As you can see in my diagram, I cannot go and change metric value on each interfaces from each module on 6500 switch (where many servers are connected), as there are too many of them from on each switch.

So I am wondering, changing metric on one interface, would make the difference on other branch office routers to make one switch as a successor and other one as feasible-successor.

changing the K value on one switch and keeping K value default on primary switch and on other branch routers will make adjacencies go down, right? as K-value mismatch.

Look forward to hear from you.

thanks

There are a couple of potential approaches depending on your IP addressing

1) If you can summarize the local networks you could advertise the specific subnets from the 6500 you wanted to use as the path and then use the "ip summary-address eigrp ..." on the interface on the other 6500 that connects to the provider cloud.

2) if you can't summarise the local networks then you could use an EIGRP offset list on the interface that connects to the provider cloud -

EIGRP offset-list

Jon

View solution in original post

Reza Sharifi · ‎12-04-2009

If you want to prefer one link over the other, you will have to change the bandwidth and delay by using the command "metric weights" under EIGRP routing protocol. I would be very careful in changing these parameters as they can have adverse effects in your network.

Here is the link to 6500 commnad reference guide:

http://www.cisco.com/en/US/docs/ios/iproute/command/reference/irp_eig2.html#wp1011716

HTH

Reza

rizwanr74 · ‎12-04-2009

Thanks Reza,

I am familiar with changing the metric value but the question is on which interface?

As you can see in my diagram, I cannot go and change metric value on each interfaces from each module on 6500 switch (where many servers are connected), as there are too many of them from on each switch.

So I am wondering, changing metric on one interface, would make the difference on other branch office routers to make one switch as a successor and other one as feasible-successor.

changing the K value on one switch and keeping K value default on primary switch and on other branch routers will make adjacencies go down, right? as K-value mismatch.

Look forward to hear from you.

thanks

Jon Marshall · ‎12-05-2009

rizwanr74 wrote:

Thanks Reza,

I am familiar with changing the metric value but the question is on which interface?

As you can see in my diagram, I cannot go and change metric value on each interfaces from each module on 6500 switch (where many servers are connected), as there are too many of them from on each switch.

So I am wondering, changing metric on one interface, would make the difference on other branch office routers to make one switch as a successor and other one as feasible-successor.

changing the K value on one switch and keeping K value default on primary switch and on other branch routers will make adjacencies go down, right? as K-value mismatch.

Look forward to hear from you.

thanks

There are a couple of potential approaches depending on your IP addressing

1) If you can summarize the local networks you could advertise the specific subnets from the 6500 you wanted to use as the path and then use the "ip summary-address eigrp ..." on the interface on the other 6500 that connects to the provider cloud.

2) if you can't summarise the local networks then you could use an EIGRP offset list on the interface that connects to the provider cloud -

EIGRP offset-list

Jon

rizwanr74 · ‎12-13-2009

Thanks Jon.

It works. Thanks a million for your input.

I found a doc from Cisco site as well...

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800c2d96.shtml

Kind Regards