topic ASA5505 MAC Address in Network Security

ASA5505 MAC Address

angel-moon — Tue, 12 Mar 2019 03:24:49 GMT

Weird question but does anyone know if the MAC addresses on an ASA5505 is on the label on the box anywhere? I am pretty sure the serial number is there. I have an ISP that needs the MAC address and the device has already been shipped to non-techies.

All replies rated. Thanks in advance

Re: ASA5505 MAC Address

Jouni Forss — Fri, 03 Jan 2014 21:17:50 GMT

Hi,

I have a couple of ASA5505 units at home and they dont have any information of the MAC address and to be honest I am not sure if the MAC address can always be the same. The MAC address visible to the ISP will be the MAC address of the Vlan interface that is facing the ISP.

I would imagine that the ISP can see the MAC address of the unit when they have connected it to the local WAN connection even if it doesnt get an address.

You might also be able to connect to some network device that acts as a DHCP server and remotely check the DHCP server so you can find out the MAC address of the ASA unit.

- Jouni

Re: ASA5505 MAC Address

angel-moon — Fri, 03 Jan 2014 22:03:47 GMT

Thanks for the response. I meant the box that teh ASA comes in and not the unit itself. The ISP can indeed see the MAC address but want me to verify what they see before they activate the modem.

Re: ASA5505 MAC Address

johnlloyd_13 — Sat, 04 Jan 2014 13:36:18 GMT

Hi,

To my knowledge no. The stickers on the box usually tells the product and serial number of the device.

You'll need to ask a tech guy to console and do a 'show version' command to get the MAC addresses.

Sent from Cisco Technical Support iPhone App

ASA5505 MAC Address

Jouni Forss — Sat, 04 Jan 2014 14:52:55 GMT

Hi,

I guess there is no "easy" way to get the MAC address then other than to have the people that got the device console into the device as John said. That is if they have a laptop with the proper port. Then they can just get Putty for example and console into the ASA. Should not really be hard for anyone.

Seems to me that my ASA for example uses the Internet-Data0/0 interfaces MAC address for all the Vlan interfaces and this will be the MAC address which shows to the ISP if it for example wants to bind your ASA MAC address to a IP address that the DHCP server will always allocate to this device only.

Some output from my ASA5505 for example (partial outputs)

ASA# sh ver

0: Int: Internal-Data0/0 : address is 0025.45f4.0aa2, irq 11

ASA# sh interface Vlan 10 | inc MAC

MAC address 0025.45f4.0aa2, MTU 1500

ASA# sh interface Vlan 1 | inc MAC

MAC address 0025.45f4.0aa2, MTU 1500

ASA# sh interface Vlan 20 | inc MAC

MAC address 0025.45f4.0aa2, MTU 1500

- Jouni