Jon Marshall Sun, 05/13/2007 - 22:47


Without a bit more detail it's difficult to say. Are you talking about routing on a Cisco router, switch or end device.

What devices arfe between the subnets that your are routing from to. And are you just concerned with using static routes or are you running a routing protocol.

Jon Mon, 05/14/2007 - 05:10

it's a 6500 series core switch. All the 3000 series switches are connected to the 2 core switch. There's no routing protocol used.

What would be the different in this case if it's a static route or routing protocol?


Jon Marshall Mon, 05/14/2007 - 05:17


Using a routing protocol allows you to add a new subnet and have it automatically propogated to other L3 devices. If the subnet becomes unavailable it will also be removed from the routing table.

You don't get this with static routes. If you add another subnet you need to remember to add another static route. If the subnet becomes unavailable the static route will still be there in your configuration.

Do your 3000 switches have L3 vlan interfaces on them ?. If they are just layer 2 switches and all the inter-vlan routing is done on the 6500's then you don't need to add static routes other than maybe a default route to a WAN router.

If the 3000 switches are layer 2 only then you just need to add a default gateway so you can remotely manage them.



mohammedmahmoud Sun, 05/13/2007 - 23:11


A more specific route is preferred, especially when you have many subnets, a default gateway is used as a last resort route for packets that don't have an exact match, accordingly i'll recommend that you do it via a more specific ip route.

HTH, please do rate all helpful replies,

Mohammed Mahmoud.

sundar.palaniappan Mon, 05/14/2007 - 05:19

If your core switches are routing between the VLANs then you don't need to any static routes at all or you don't need any routing protocol. All the routes will show up as directly connected routes in the routing table. The only thing that's needed is the layer 2 switches have to be configured with a 'ip default-gateway' command to point to their respective VLAN int IP of the core switch.


Sundar Mon, 05/14/2007 - 07:40


What should be added into the core switch if i want to enable the client to be able to access a public static ip address? should i use the ip default-gateway on the router or ip route to route traffic to the public ip address? Can i use default route command in this case? What's the different between this 3 commands?


Richard Burts Mon, 05/14/2007 - 08:26


ip default-gateway is configured when the device is not routing ip. It is typically used on layer 2 switches can not route ip. It can be configured on layer 3 switches but would not be used unless the switch was not routing ip (could be the case if "no ip routing" is configured, or could happen if boots into (boot) mode rather than normal mode).

So for your core switches you would need to configure ip route statements for the various destinations (probably including an ip route to allow users to access outside/public addresses.




This Discussion