WAN Interface only connects on 100baseT not Gigabit

[plc101man]

I just got a new Arris T25 Cable modem that I registered fine with Xfinity, but the WAN interface only connects on 100baseT not gigabit. I take the cable from the cable modem and plug it to another interface it connects fine to gigabit speeds. I have checked the interface speed and duplex settings and they are set to default on the WAN interface and also the others. Do I have a bad port ?

Any ideas ?

Any help will greatly appreciated.

[Fright]

you  can try to set mediatype through shell and see if it help

[bartjsmit]

Replace the cable modem with a switch and confirm that the cable and WAN port negotiate at gigabit. Check the cable for crimp defects, especially if you crimped it yourself and swap it out for a manufactured one if you can.

Once you're convinced that the mechanics are fine, set your WAN adapter speed and duplex in the web GUI rather than rely on autoselect.

What is the NIC type?

Bart...

[plc101man]

The NIC is an Intel I211-AT- 10/100/1000 Controller.

Thanks for the quick responses guys.

I did a power cycle on both cable modem and Firewall and the speed of the WAN nic in the firewall is Gigabit now.

Let's hope that it continues to work fine.

Thanks