I have intervlan routing setup on D1

Hi all,

Basically i have intervlan routing setup on D1 (Layer 3 Switch).

I am wondering what should i configured on D2 (Layer 3 Switch) as both of them are connected to the access layer pc with redundant links.

Confusion:

- If i make a copy of D1, duplicate ip address occured due to the vlan interfaces

my topology are:

D1

---

(Etherchannel) to D2

VLAN 10 connected to D1
VLAN 20 connected to D2
VLAN 10 connected to D1
VLAN 20 connected to D2

I assume here that the Etherchannel between D1 and D2 is configured as TRUNK. (It should be, otherwise it won't work since you will be having two VLAN 10s and two VLAN 20s in different segments). I assume also that ip routing command is enabled on both switches.

If the above it correct, then use different IP addresses for each VLAN interface on each switch. For example, if VLAN 10 has a range 10.1.1.0 /24. Use say 10.1.1.1 on VLAN 10 interface on D1 and use say 10.1.1.2 on VLAN 10 interface on D2. Same goes for VLAN 20.

Ofcourse in this case you will have TWO gateways per VLAN, which you can configure PC's to use either one of them.

Another way, is to simply disable routing on one of the switches and let the other switch do the routing. You can do this using the no ip routing command.

I hope this helps.

Ok, just in case i get confused again. Do i have to setup Intervlan-routing on D2?

Hi Ammar,

Your answer really rocks It is indeed helpful for me too. Well would you mind shed some light on my Question www.firewall.cx/modules.php?name=Forums&...ic&p=37124#37124

Thanks in advance

Ok, just in case i get confused again. Do i have to setup Intervlan-routing on D2?

No, assuming that D1 is doing Intervlan-routing.

rizin: Thanks , will do

Ok, just in case i get confused again. Do i have to setup Intervlan-routing on D2?

No, assuming that D1 is doing Intervlan-routing.

rizin: Thanks , will do

If i setup D1 as primary for stp and D2 as primary for stp, can i do intervlan-routing.. if D1 is down, D2 can take over intervlan-routing..

In this case, i need to setup DHCP pool for D1 and D2? Since the gateway will be different.

For example,

D1 - 10.1.1.1
D2 - 10.1.1.2

PC1 connected to D1

- IP address: 10.1.1.3 ,
- Subnet mask: 255.255.255.0
- Gateway: 10.1.1.1

if D1 is down, PC1 will need to configure the gateway to 10.1.1.2. --> Do i need another DHCP pool for this?