Ghost entry in CAM table.

[chandra_rc16]

Hi All,

Here is my topology and i configured etherchannel using the two Fa0/1,Fa0/2 ports.

Here is the output from "show mac-address-table"

Switch1#show mac-

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   1    0001.4235.89de    DYNAMIC     Po1

   1    000a.4162.e601    DYNAMIC     Fa0/1

   1    000a.4162.e602    DYNAMIC     Fa0/2

   1    0090.0cd2.b55e    DYNAMIC     Po1

   1    00d0.d303.c598    DYNAMIC     Fa0/15

Switch2>show mac-a

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   1    0000.0ca2.138b    DYNAMIC     Po1

   1    0003.e467.9001    DYNAMIC     Fa0/1

   1    0003.e467.9002    DYNAMIC     Fa0/2

   1    0040.0b5b.6c9e    DYNAMIC     Po1

   1    00d0.d303.c598    DYNAMIC     Po1

Switch2>ex

From where did the bolded interface come into play. Can someone please let me know ? I'm i missing anything basics?

Regards,
Chandu       

[chandra_rc16]

Forgot to bold the ghost MAC's

Switch1#show mac-

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   1    0001.4235.89de    DYNAMIC     Po1

   1    000a.4162.e601    DYNAMIC     Fa0/1

   1    000a.4162.e602    DYNAMIC     Fa0/2

   1    0090.0cd2.b55e    DYNAMIC     Po1

   1    00d0.d303.c598    DYNAMIC     Fa0/15

Switch2>show mac-a

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   1    0000.0ca2.138b    DYNAMIC     Po1

   1    0003.e467.9001    DYNAMIC     Fa0/1

   1    0003.e467.9002    DYNAMIC     Fa0/2

   1    0040.0b5b.6c9e    DYNAMIC     Po1

   1    00d0.d303.c598    DYNAMIC     Po1

Switch2>ex

Are these two the mac address of the port-channel interfaces ? If yes, then how can i see that ?

Regards,
Chandu

[Rolf Fischer]

Chandu,

you can try 'show interfaces Po1', the second line of the output should show the MAC address.

If PT supports it, you can also try 'show interfaces | include line pro|bia' to see all interfaces MAC addresses.

HTH

Rolf

[chandra_rc16]

Hi Rolf,

It seems like PT is not supported to show interfaces po 1 and also the show interfaces command didn't show up the portchannel interface.. it just showed all the physical interfaces & Vlan interface.

So i think this is one more of the limitiation of PT.

And so finally, to conclude those MAC where of portchannels only right ?

Thanks for you help.

Regards,
Chandu

[Rolf Fischer · Accepted solution]

It seems that the c3560 in PT shows the portchannel-interface but the c2960 does not:

c3560# show interfaces

(...)

Port-channel 1 is up, line protocol is up (connected)

  Hardware is Lance, address is 0001.9681.e02c (bia 0001.9681.e02c)

(...)

c2960# show mac address-table dynamic

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   1    0001.639b.7801    DYNAMIC      Fa0/1

   1    0001.639b.7802    DYNAMIC      Fa0/2

   1    0001.9681.e02c    DYNAMIC      Po1

HTH

Rolf