Hardcoding Mac Address for STP?

ciscoman2012

I believe it was the instructor from INE that did this and I can't for the life of me remember the series of commands he used. Does anyone know how to do this?

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Forsaken_GA

ciscoman2012 wrote: »

I believe it was the instructor from INE that did this and I can't for the life of me remember the series of commands he used. Does anyone know how to do this?

mac address-table static <mac address> vlan <vlanid> interface <interface>

ciscoman2012

Forsaken_GA wrote: »

mac address-table static <mac address> vlan <vlanid> interface <interface>

Ok so I would do this with an interface that I have trunking with another switch?

Forsaken_GA

ciscoman2012 wrote: »

Ok so I would do this with an interface that I have trunking with another switch?

That depends, what exactly are you trying to do? Your original question was a bit vague, and I answered with what I judged to be most likely what you were looking for, though I could be wrong.

ciscoman2012

Forsaken_GA wrote: »

That depends, what exactly are you trying to do? Your original question was a bit vague, and I answered with what I judged to be most likely what you were looking for, though I could be wrong.

I thought there was a command that let you change the mac address of the switch itself. In this case the switch's mac is 000e.84a4.a480 and I would like to change it to something else.

SW5#sh spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24577
Address 000e.84a4.a480
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 24577 (priority 24576 sys-id-ext 1)
Address 000e.84a4.a480
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300

Interface Role Sts Cost Prio.Nbr Type

---- ---

Fa0/8 Desg FWD 19 128.8 P2p
Fa0/9 Desg FWD 19 128.9 P2p

Rakurai

Been watching the STP videos of INE for the past couple of days, the only thing I've seen him change for MAC address was the interfaces on the router. Was simple mac-address __________ command on the interface.

ciscoman2012

Rakurai wrote: »

Been watching the STP videos of INE for the past couple of days, the only thing I've seen him change for MAC address was the interfaces on the router. Was simple mac-address __________ command on the interface.

I went back and watched the videos and realized that's what he did. That also got me to think about if it was possible to change the hard coded mac addresses that the switches are shipped with?

Forsaken_GA

ciscoman2012 wrote: »

I went back and watched the videos and realized that's what he did. That also got me to think about if it was possible to change the hard coded mac addresses that the switches are shipped with?

Keep in mind that in later IOS versions, Cisco has removed that command. You mess with MAC addressing at your own peril and risk of causing connectivity issues. Changing MAC's to influence STP is far from a normal operation, that's what priority is for.

ciscoman2012

Forsaken_GA wrote: »

Keep in mind that in later IOS versions, Cisco has removed that command. You mess with MAC addressing at your own peril and risk of causing connectivity issues. Changing MAC's to influence STP is far from a normal operation, that's what priority is for.

Thanks for the information Forsaken. I've normally just been doing the spanning tree vlan XX root primary command and that seems to be working. Just wondering in the back of my head if it was possible to change the hard-coded MAC address or not. I believe I have my answer now. Thanks guys!