ISP DHCP + ASA5505 = no ip

rwagner · ‎04-06-2010

The title says it all.

I have an ASA5505 connected to a residential ISP provider. I configured the WAN port as a DHCP client. The ASA recieved no IP address from the ISP.

I then put in a netgear router as my border device and configured the WAN port as a DHCP client. It recieved a IP address from the ISP. Then I configured the LAN port with a DHCP server and connected the ASA WAN port directly to the netgear LAN. The ASA recieved the IP address from the netgear router.

I would like to remove the netgear router and put the ASA as my border device, but the ISP (comcast) residential support people are pretty much useless.

NOTE: I will double check my current ASA IOS, but i am aware of the version update for 7.2.(2).22 and how the ASA wasn't sending a client-id. I already did that update and set the client-id for the ASA mac-address. That didn't resolve the issue.

rtjensen4 · ‎04-06-2010

You might have to call your ISP and have them release your IP... some ISPs only alot you 1 DHCP address with a relatively annoying lease timeout. You can probably wait for it to timeout by having NOTHING attached for a while, maybe reboot your modem OR you could call the ISP OR you could put the MAC address of your Netgear onto your ASA. I did that with my FiOS Service... works fine. HTH

rwagner · ‎04-06-2010

Well the good news is that I got it fixed.

SOLUTION:

1) need ASA IOS 7.2.(2).22 or higher

2) DO NOT USE 'Cisco-interfaxce_name-' as the client-id

3) perform the command:

Interface vlanX
        dhcp client route distance 1
        ip address dhcp setroute
      dhcp-client client-id interface outside

with vlanX being the correct vlan for your outside interface.

I actually had to do it twice before it would work right. My current IOS is 8.0(4)

NOTE: running the command "dhcp-client client-id interface outside" is not enough by itself