Connecting a hardware firewall to Virgin cable modem

[iggypop]

Hi all,

This is question to any network experts using virgin cable media, any help much appreciated :)!

I am trying to network a firewall (ethernet using standard DHCP) to the ethernet port on an Virgin media Ambit cable modem.

The modem networks fine when connected to various computers using ethernet and DHCP.

When connected to the firewall it wont issue an address, it times out despite reloading devices at various times to force the address lease.

My question is do virgin Ambit cable modems only issue dynamic addresses to certain Mac address classes? The firewall is a Fortigate 60 with ext eth 00:09:0F

Thanks

[zing_deleted]

you are rebooting the modem ?

[iggypop]

Hi zinglebard, thanks for your reply - Yes I hard reset it and sw reloaded it, its a full blown firewall with up down commands as per cisco ios. I am going to rig up a dhcp server from a switch and see if the firewall nic can pickup an address from that as a test..

[zing_deleted]

By the look of your post I did not actually think you would miss that out but as you know the modem would only assign an IP to the firewall after a reboot but you didnt mention it so I had to ask :)

[Jon T]

you are rebooting the modem ?

As Zing says, you need to reboot your CM to allow it to associate with another client MAC address.

I've connected Cisco, Stonegate and Watchguard equipment to my cable modem and never had a problem.

[iggypop]

I that case I will give it another try. I just tested the firewall nic with a standard dhcp server and it worked fine!

How long did it take for the cisco kit to get an address after you rebooted the cm?

[indie1982]

How long did it take for the cisco kit to get an address after you rebooted the cm?

I've done it with a PIX 501, it had no trouble picking up an address, don't know exactly but I'd think no longer than a few seconds.

[iggypop]

Thanks everyone, your were correct and it did eventually work. The firewall finally got an address after a careful sequence of rebooting devices and a few minutes wait. It gets a new address instantly now so its good to go!