Cat 3560 show mac-address-table

Answered Question
Oct 14th, 2009
User Badges:

I have a Catalyst 3560-48TS-S running IPBASE ver 12.2(35)SE5 IOS.


When I do show mac-address-table dynamic it only shows the addresses it is learning via its uplink port Gi0/1. No addresses are shown for any of its Fast Ethernet interfaces.


I haven't had this issue with the other switches in my network. I've looked in the Bug Tool Kit but can't find anything related. Does anyone have a suggestion as to how I can see the MAC addresses on the Fe interfaces?


regards,


Mark

Correct Answer by Giuseppe Larosa about 7 years 7 months ago

Hello Mark,


>> MAC addresses on the switch ports are showing as static. I do have port security turned on, would this be the reason?


yes it is for port security.


the command syntax may have changed two times:


it was

show mac-address-table on older devices

then became

show mac address-table


now in newer devices that are installed in our network is again

show mac-address-table


Hope to help

Giuseppe


Correct Answer by ross.wood about 7 years 7 months ago

Hey,


The commmand you will need is:


show mac address-table interface fast 0/1


This will show you what mac addresses are on the local interface. Keep in mind if it doesn't show a mac address for the interface even though the interface is up it could be because no traffic has passed through the switchport. Best thing to do is ping the IP address of whats connected to the switchport then use the above command to see the mac address.


HTH


Ross.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (2 ratings)
Loading.
Correct Answer
ross.wood Wed, 10/14/2009 - 17:25
User Badges:

Hey,


The commmand you will need is:


show mac address-table interface fast 0/1


This will show you what mac addresses are on the local interface. Keep in mind if it doesn't show a mac address for the interface even though the interface is up it could be because no traffic has passed through the switchport. Best thing to do is ping the IP address of whats connected to the switchport then use the above command to see the mac address.


HTH


Ross.

Lucien Avramov Wed, 10/14/2009 - 18:14
User Badges:
  • Red, 2250 points or more

Mark,


What do you get from just a show mac-address command?



Ross,

Show mac address-table dynamic encompass the command show mac address-table interface.



markrawson Wed, 10/14/2009 - 18:59
User Badges:

Ahh, a change of syntax for the command has occurred somewhere along the line.


On all my other switches to get the dynamic MAC addresses I enter either:


show mac-address-table dynamic


to get all of the addresses or:


show mac-address-table dyn int fas 0/1


to get the particular interface.


If I enter the command as above with this version of IOS it comes back with no entries, however, if I enter:


show mac-address-table int fas 0/1


I get the dynamic MAC addresses appearing.



Edit: I just noticed that what I thought would be dynamic MAC addresses on the switch ports are showing as static. I do have port security turned on, would this be the reason?


I have the same port security settings on some 3550's but they don't exhibit the same behavior.


Correct Answer
Giuseppe Larosa Thu, 10/15/2009 - 00:05
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Mark,


>> MAC addresses on the switch ports are showing as static. I do have port security turned on, would this be the reason?


yes it is for port security.


the command syntax may have changed two times:


it was

show mac-address-table on older devices

then became

show mac address-table


now in newer devices that are installed in our network is again

show mac-address-table


Hope to help

Giuseppe


Actions

This Discussion