Solved: Switch MAC Address

Urfan Khaliq · ‎01-02-2008

Hi, Can anyone please help...I am trying to find out the MAC address that a 3560G would use for DHCP requests as it turns out it is not the base mac address you get from a show ver....

Is there a command to see the mac address(es) associated with a 3560G?

Much apprecieated

Urfan

Jon Marshall · ‎01-02-2008

Urfan

Are you talking about the switch itself getting an IP address to use ?.

If so it should be the vlan interface that you are using for management of the switch - vlan 1 by default unless you have changed it.

Jon

View solution in original post

Jon Marshall · ‎01-03-2008

Hi Urfan

Apologies if i am still not understanding but the following command "sh int | include line protocol | Hardware" (note NOT "sh int | include line | EtherSVI) gives the following

SW1#sh int | include line protocol | Hardware

Vlan1 is up, line protocol is up

Hardware is EtherSVI, address is 0019.060d.1c40 (bia 0019.060d.1c40)

FastEthernet0/1 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c03 (bia 0019.060d.1c03)

FastEthernet0/2 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c04 (bia 0019.060d.1c04)

FastEthernet0/3 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c05 (bia 0019.060d.1c05)

FastEthernet0/4 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c06 (bia 0019.060d.1c06)

FastEthernet0/5 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c07 (bia 0019.060d.1c07)

FastEthernet0/6 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c08 (bia 0019.060d.1c08)

FastEthernet0/7 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c09 (bia 0019.060d.1c09)

FastEthernet0/8 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c0a (bia 0019.060d.1c0a)

FastEthernet0/9 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c0b (bia 0019.060d.1c0b)

FastEthernet0/10 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c0c (bia 0019.060d.1c0c)

FastEthernet0/11 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c0d (bia 0019.060d.1c0d)

FastEthernet0/12 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c0e (bia 0019.060d.1c0e)

FastEthernet0/13 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c0f (bia 0019.060d.1c0f)

FastEthernet0/14 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c10 (bia 0019.060d.1c10)

FastEthernet0/15 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c11 (bia 0019.060d.1c11)

FastEthernet0/16 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c12 (bia 0019.060d.1c12)

FastEthernet0/17 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c13 (bia 0019.060d.1c13)

FastEthernet0/18 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c14 (bia 0019.060d.1c14)

FastEthernet0/19 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c15 (bia 0019.060d.1c15)

FastEthernet0/20 is down, line protocol is down (notconnect)

Hardware is Fast Ethernet, address is 0019.060d.1c16 (bia 0019.060d.1c16)

FastEthernet0/21 is up, line protocol is up (connected)

Hardware is Fast Ethernet, address is 0019.060d.1c17 (bia 0019.060d.1c17)

FastEthernet0/22 is administratively down, line protocol is down (disabled)

Hardware is Fast Ethernet, address is 0019.060d.1c18 (bia 0019.060d.1c18)

FastEthernet0/23 is administratively down, line protocol is down (disabled)

Hardware is Fast Ethernet, address is 0019.060d.1c19 (bia 0019.060d.1c19)

FastEthernet0/24 is administratively down, line protocol is down (disabled)

Hardware is Fast Ethernet, address is 0019.060d.1c1a (bia 0019.060d.1c1a)

GigabitEthernet0/1 is down, line protocol is down (notconnect)

Hardware is Gigabit Ethernet, address is 0019.060d.1c01 (bia 0019.060d.1c01)

GigabitEthernet0/2 is down, line protocol is down (notconnect)

Hardware is Gigabit Ethernet, address is 0019.060d.1c02 (bia 0019.060d.1c02)

Jon

View solution in original post

Jon Marshall · ‎01-02-2008

Urfan

Do you mean the switch forwarding on DHCP requests with the "ip helper-address" command.

If so the mac-address will be the one that is on the L3 interface connected to DHCP server vlan.

Or did you mean something different.

Jon

farkascsgy · ‎01-02-2008

Hello,

show interface vlan 10 shows the MAC address of your VLAN10 interface, also you can check the connected devices' (like PC) MAC addreses with show mac-address-table command.

bye

FCS

Please rate me if I helped.

Urfan Khaliq · ‎01-02-2008

mmm Im not sure....What im trying to find out is the mac address that the switch will use to request an IP address in order for the DHCP based auto configuration and the DHCP Client Request Process...

We have a DHCP server which is based on mac addresses and hands out IP addresses pre assigned to every MAC address...it is for this that I need the MAC address that the switch will request an IP against..

http://www.cisco.com/en/US/products/hw/switches/ps5528/products_configuration_guide_chapter09186a0080878d41.html

Urfan

Jon Marshall · ‎01-02-2008

Urfan

Are you talking about the switch itself getting an IP address to use ?.

If so it should be the vlan interface that you are using for management of the switch - vlan 1 by default unless you have changed it.

Jon

Urfan Khaliq · ‎01-02-2008

Aah yes your Right. Thanks Jon...so am I right in thinking that the only way to find out that mac address is sho int vlan 1? is there a command that will give me all the mac addresses that the switch has?

Urfan

farkascsgy · ‎01-02-2008

If you issue the show mac-address-table command you will see

Vlan Mac Address Type Ports

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

All 00xx.xxxx.xxxx STATIC CPU

These belongs to the switch itself and not to the connected devices.

For DHCP concern you need to see the management vlan's address in the DHCP server's log. Not a good idea to use VLAN1 as management VLAN.

bye

FCS

PLease rate me if I helped.

Urfan Khaliq · ‎01-02-2008

Hi Thanks for that but thats not quite what I am looking for...I am after a complete list of MAC addresses associated with a switch....so at the very least that would be one for each port and the vlans etc?

Urfan

farkascsgy · ‎01-02-2008

Sir,

show mac-address-table command shows the CAM atble of the switch which contains all MAC addresses which is connected to the switch, including the local VLAN interfaces.

Please check it on a device.

bye

FCS

Please rate me if I helped.

Urfan Khaliq · ‎01-02-2008

Hi,

Im afraid you are mistaken or you are not understanding the question...I am wanting the complete list of Mac addresses available to the switch so taht would be one for each port I would imagine at the least? I have done the show mac-address-table command and output is attached. As you can see it is not what I am after...

Urfan

farkascsgy · ‎01-02-2008

Was there any connected device when you issued the show mac-address-table command?

show ip interface brief shows the port status (should be up up)

I am sure that your friend is the show mac-address-command

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat4000/12_18a/command/show1.htm#1024439

http://articles.techrepublic.com.com/5100-1035_11-6125413.html

bye

FCS

Please rate me if I helped.

Urfan Khaliq · ‎01-02-2008

hi nothing is connected to the switch and as I am just connectd via a console cable.

I am stuck with this as this is really bugging me! I thought there was a command which would give me all the mac addresses that the switch uses (not the mac addresses of devices connected to the switch)

Urfan

farkascsgy · ‎01-02-2008

Urfan,

From the output you can see the STATIC and CPU label, these MACs belong to the switch the DYNAMIC ones are learned from the connetced devices, you can also add static mac addresses to the swithcport if you want.

bye

FCS

Please rate me if I helped.

Urfan Khaliq · ‎01-02-2008

Then how is it that the base mac address is not in the list neither is the vlan1 mac address?

Urfan

farkascsgy · ‎01-02-2008

Look at this page:

http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00801c9b4e.shtml#topic1

bye

FCS

Please rate me if I helped.