layer 2 switch - ip routing

[suthomas1]

Hi,

This is a very naive question but i am posing this out of curiousity.

I have a 2960 which is only layer 2 ( the route table shows nothing ) switch connected in the network as an edge switch with its default gateway

set to core switch ip. i only have one layer 2 vlan configured on this 2960 which is the management interface for this switch.

if i were to enable ip routing command on this switch , what will be the effect.

Appreciate all inputs!

[kcnajaf]

Hi Thomas,

When you enable ip routing ip default-gateway command is ignored as this works only with L2 devices and you need to have a default route (which points to core switch) to have ip reachability to your 2960 switch.

Hope this is what you are looking for.

Regards

Najaf

Please rate when applicable or helpful !!!

[paul driver]

Hello

Dont think you can its L2 switch!

Res
Paul


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[kcnajaf]

Hi Pdriver,

The 2960 is a Layer 2 switch but it does support basic static routing/default routing on SVI interfaces only.  This is from the 12.2(55)SE SCG:

Hope that helps

Regards

Najaf

[suthomas1]

Thanks. So if ip routing is enabled on this switch, the 2960 shouldn't be accessible from the lan network( assuming the administrative workstation is connected on vlan 15 with ip 1.1.15.15 & the 2960 has management vlan 25 with ip 2.2.2.25.

Is this correct ? If so, will it then be accessible from the core network device which will have its vlan25 SVI?

thanks again!!

[paul driver]

Hello
After checking the cco docs it does look like its supported but not by default - you may need to change the sdm template to enable it

http://www.cisco.com/en/US/docs/switches/lan/catalyst2960/software/release/12.2_55_se/configuration/guide/swipstatrout.html

Res
Paul

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[kcnajaf · Accepted solution]

Hi Thomas,

It depends.

If you have a defualt route on you 2960 which point to your core that is all you need for your device to be accessed from any VLAN. Also if you are using vlan 25 as managment on 2960 then this vlans has to be trunked all the way to core for your 2960 to reach its gateway.

The point to be noted here is that the actual routing is done by your core device. So if vlan 15 user try to reach 2960 managment the request would initially come to the Core and core will the MAC address for 2.2.2.25 (2960 managment ip) and traffic will be send to that MAC address.

Hope i'm clear here.

Regards

Najaf

Please rate when applicable or helpful !!!

[Ravi Singh]

The 2960 is a Layer 2 switch but it does support basic static  routing/default routing on SVI interfaces only.  This is from the  12.2(55)SE.

When you enable ip routing ip default-gateway command is ignored as this  works only with L2 devices and you need to have a default route (which  points to core switch) to have ip reachability to your 2960 switch.