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What version of IOS is been used ?

Post output of show version

Did you try:

int fa2
no switchport
exit

> What version of IOS is been used ?
>
> Post output of show version
>
> Did you try:
>
> int fa2
> no switchport
> exit

Cisco IOS Software, C181X Software (C181X-ADVIPSERVICESK9-M), Version
12.4(6)T3, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2006 by Cisco Systems, Inc.
Compiled Fri 21-Jul-06 15:17 by kellythw

ROM: System Bootstrap, Version 12.3(8r)YH8, RELEASE SOFTWARE (fc2)

c1811-turaevo uptime is 4 days, 2 hours, 5 minutes
System returned to ROM by power-on
System image file is "flash:c181x-advipservicesk9-mz.124-6.T3.bin"
---------------
I'm not sure how no switchport helps? I try to change MAC on vlan
interface.
Well, anyway I tried 'no switchport' but it did not help. Just
disconnect fa2 from vlan2.

--
Sem.

Perhaps can be acccomplished using HSRP

interface Vlan99
ip address 99.99.99.98 255.255.255.0
standby ip 99.99.99.99
standby 99 mac-address aaaa.aaaa.aaaa
end

Merv wrote:
> Perhaps can be acccomplished using HSRP
>
> interface Vlan99
> ip address 99.99.99.98 255.255.255.0
> standby ip 99.99.99.99
> standby 99 mac-address aaaa.aaaa.aaaa
> end

So it does!

#sh int vlan1 | inc rotocol|bia
Vlan1 is up, line protocol is up
Hardware is EtherSVI, address is 0019.2f48.xx60 (bia 0019.2f48.xx60)
#sh int gi 0/0 | inc rotocol|bia
GigabitEthernet0/0 is up, line protocol is up
Hardware is BCM1125 Internal MAC, address is 0019.2f48.xx60 (bia
0019.2f48.xx60)

Thing is, this does not usually matter, it is normal
for example for Sun workstations to use the same mac
on all interfaces, there are millions out there.

Since a Cisco router will not normally let you put the same
IP subnet on more than one interface the two interfaces
never "see" each other.

You can also do this:-

interface FastEthernet1/5
description
no switchport
ip address xxx.xxx.98.65 255.255.255.224

In this config the ports get their own individual macs.

FastEthernet1/4 is up, line protocol is up
Hardware is Fast Ethernet, address is 0018.1926.xxbe (bia
0018.1926.xxbe)
FastEthernet1/5 is up, line protocol is up
Hardware is Fast Ethernet, address is 0018.1926.xxbf (bia
0018.1926.xxbf)

This is a NM-16ESW in a 3845.

Why do you think that this is something to worry about?

> Perhaps can be acccomplished using HSRP
>
> interface Vlan99
> ip address 99.99.99.98 255.255.255.0
> standby ip 99.99.99.99
> standby 99 mac-address aaaa.aaaa.aaaa
> end

Great! Thanks! It works.

--
Sem.