thanks for your reply Giuseppe! That means ifwe have(multilayer switch) distribution switches d1 and d2,connected to layer 2 core switch c1 by f0,f1 i.e

d1f0---------c1------------f0 d2

f1------- ------------f1

Then we can't use single vlan say 2 to put d1 and d2 interfaces f0,f1,f0,f1 because:

1)f0, f1 both require different ip subnet, 2)the best design practise dictates one to one correspondence between vlan and ip subnet.our options are:

1) remove the redunant link say f1 from switches d1,d2 and use single subnet for f0 on both d1 and d2 and use one vlan to put f0 on both d1 and d2.

or

2) use two vlans and put f0 on switches in one vlan say vlan 1 and use other vlan say vlan 2 to put f1 on both d1 and d2 in that vlan and use two subnets, one for each port f0,f1.

Am i right?

thanks a lot!

Hello Sarah,

your understanding is correct.

Actually the correction I had suggested was this: two vlans, two subnets, two interfaces on each router

Hope to help

Giuseppe

Thanks a lot Giuseppe!

Sarah, when you discuss multilayer switches, rather than your initial post's reference to router, your options may change. Most multilayer switches can have the same IP address appear on multiple ports. You also have, with most mutlilayer switches, the option of using L2 or L3 connections between devices. What is it you're really trying to accomplish and with what type of devices?

Thanks for your reply Josephoherty!

I was actually reading a cisco guide on switching( i am preparing for ccnp) about how the access layer , distribution layer and core layer are implemented . It says how distribution switches can be connected to layer 3 core and layer 2 core. I was just wondering about the layer 2 core as to how distribution switch, a mulilayer switch can be connected to layer 2 core.

thanks a lot!

Sarah:

Giuseppe and Joseph are 100% correct. See below:

NJLEO2CH-WR02#sh run int GigabitEthernet0/0

Building configuration...

Current configuration : 159 bytes

!

interface GigabitEthernet0/0

ip address 192.168.59.21 255.255.255.248

duplex auto

speed auto

end

NJLEO2CH-WR02#

NJLEO2CH-WR02#

NJLEO2CH-WR02#conf t

Enter configuration commands, one per line. End with CNTL/Z.

NJLEO2CH-WR02(config)#int GigabitEthernet0/1

NJLEO2CH-WR02(config-if)#ip address 192.168.59.22 255.255.255.248

% 192.168.59.16 overlaps with GigabitEthernet0/0

NJLEO2CH-WR02(config-if)#