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New Member

Switch MAC address questions

a layer 2 catalyst switch with 24 10/100 port like 2960,

1- this guy has 24 mac addresses for each physical layer 2 interfaces

and

the switch itself has one independent MAC address right?

2- if that is right, which MAC address is the visible one to the PCs? MAC address of the port PC is connected to or the MAC address of the switch?

3- if we create 3 vlans with 3 ip addresses for each vlan, do we get 3 mac addresses?

I assume answers to above question will not change on layer 3 switches.

tx for helping

3 REPLIES
Hall of Fame Super Silver

Re: Switch MAC address questions

1) The switch will have a MAC address for each interface. There is not an independent MAC for the switch.

2) The MAC that is visible to the PC is the MAC for the interface.

3) No matter how many VLANs you create, or how many IP addresses you assign to the VLAN interface it does not change the number of MAC addresses or the way that the MAC is used.

It would not change if it were a layer 3 switch.

HTH

Rick

New Member

Re: Switch MAC address questions

tx Rick.

so there isn't such a thing as switch's MAC address. it is Port's MAC address.

but,

'show spanning-tree command' shows MAC address of the root bridge.

all switches within the network shows the same MAC address as the MAC address of the root bridge. altought those switches are connected to root switch through different ports.

i am little confused.

tx for helping

Re: Switch MAC address questions

Hello,

for spanning tree purposes there are other MAC addresses found on the switch, besides the port MACs.

There is a discussion here at

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Career%20Certifications&topic=Training&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40%40.1dd9fb71

about where a switch takes MAC addresses for spanning tree, which should answer all your questions.

Hope this helps! Please rate all posts.

Regards, Martin

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