What is the impact of removing RIP configuration

darren-carr · ‎11-06-2008

Hi guys,

I have recently taken over the role of the network administrator in our organisation and have worked with networks for several years however I am unsure regarding a configuration that has been applied on two of our switches.

The environment I have is made up of 9 switches. I have a stack made up of four 3750e switches, two 2960Gs, one 3550 and two 3560s. The environment is made up of four VLANS and the routing between these is done by the 3560s. (the 3750 stack will soon take over this role). I have HSRP enabled on the 3560s which works well.

In two weeks time I will be replacing our current firewall solution. The routing of traffic on the network will be impacted by the change. I have carefully planned out and tested the changes and impact however I noticed a rather odd configuration on the two 3560s. The previous guy has enabled RIP! I really do not think we need it as we are a small business with around 100 users, 60 servers (small but a financial institution) 15 printers, etc. I really think that all I need to use for now is the routing capabilities of the 3560s (which is enabled).

So I guess my question is how can I be sure that RIP is not being used? Is there anyway to monitor what it is doing on the switches?

Thanks

Darren

arianto.wibowo · ‎11-06-2008

hi Darren,

You must check first about the function of RIP.

You can check with "sh ip route rip" command to see available routing in the switch.

If there is not shown anything, just remove the configuration.

If there is a routing table with RIP, In my opinion it is used for connecting to server farm or WAN or anything.

For connecting between VLAN in 3560(VLAN termination) just use "ip routing" command and no need any routing.

But to connecting to another IP segment we need routing protocol, RIP one of it.

hope this help,

aw

darren-carr · ‎11-06-2008

Hi,

Many thanks for the prompt reply.

No RIP routes exist. At present all we do is InterVlan routing here. Anything outside of the internal network is forwarded to the PIX firewall and is sent out of the business.

By enabling routing on the 3560 (which is what is currently enabled) this works well.

I really don't know why this was applied?

Any how thanks for your reply, you confirmed my suspicions! :)

Thanks again

Darren

Richard Burts · ‎11-07-2008

Darren

One other thing you might check to verify this is to do show ip protocol. It should indicate that the routing protocol is rip (no surprise) and what you really want to look for is at the bottom where it lists Routing Information Sources. If it lists any address under the Gateway heading then there is another device running rip and you might want to check what it is.

When I was teaching Cisco classes I had some students who assumed that to do routing that you must have a routing protocol running. If all you are doing is routing connected subnet (connected VLANs for intervlan routing) then you do not need a routing protocol. But the person who did the initial config may have thought that a protocol was required.

HTH

Rick

HTH

Rick

darren-carr · ‎11-07-2008

Hi Rick,

Thanks for the valuable information.

I can confirm that there are what appear to be two gateway address (there are several but physicall they all point to two switches). One of the switches is a 3550 which used to have routing enabled, the other is the combination of two 3560 with HSRP enabled.

As I stated all I am trying to achieve on the LAN is InterVlan routing which I know you can achieve by enabling routing on the two 3560's. I really want to remove RIP from the switches as I only want to have configurations applied that we actually use. My plan is to remove RIP from the switches and test the InterVlan routing to ensure all works as expected.

Does having RIP enabled add any overhead to the switches? We are only a small business with a limited VLAN configuration.

Thanks

Darren

Richard Burts · ‎11-08-2008

Darren

If you can account for all the devices in the Gateway Address which are the devices which have sent you RIP routing updates, and if all the routes in your show ip route are "C" routes and there are no "R" routes then it is safe to remove RIP from the configuration.

HTH

Rick

HTH

Rick