Ethernet interface configuration

[ksheetz]

Cisco 2600. How do I distribute traffic between 3 logical subnets on 1 internal interface, or do i need to buy another ethernet interface? thanks

[pkhatri]

Howdy,

I'm not sure I am totally clear on what you are attempting here... If you mean how you can route traffic between 3 subnets configured on the one interface, then this should happen automatically. The interface will have its primary IP address in one subnet and the other two addresses will be secondary addresses.

If that's not what you were after, pls provide more details.

Paresh.

[ksheetz]

Thanks, I've got it. How many secondary addresses can you operate on 1 interface?

[Georg Pauwen]

Hello,

as an alternative to secondary addressing, you could also configure 802.1Q trunking. Not knowing exactly which router model you have, here is a sample config for a 2611 router with 802.1Q trunking configured on the 10MB Ethernet port:

interface Ethernet0/0

no ip address

full-duplex

!

interface Ethernet0/0.1

encapsulation dot1Q 1 native

ip address 172.16.10.1 255.255.255.0

no snmp trap link-status

!

interface Ethernet0/0.2

encapsulation dot1Q 2

ip address 172.16.20.1 255.255.255.0

no snmp trap link-status

!

interface Ethernet0/0.3

encapsulation dot1Q 3

ip address 172.16.30.1 255.255.255.0

no snmp trap link-status

Obviously you would also need to create the respective VLANs on the switch(es) you have connected to the router...

HTH,

GP

[arvenugopal]

Hi

A maximum of 6 secondary address can given on a router ether interface. hope it helps

[ksheetz]

Thanks!

[Richard Burts]

I have seen a router interface with 20 secondary addresses which worked quite well.

There is not an arbitrary limit on the number of secondary addresses on a router interface.

HTH

Rick