Not getting a WAN IP address from Cox Cable

[hish747]

Connecting my OPNsense router to the Cox cable modem and can never get an IP address on the WAN side. I do get one to a computer connected to the OPNsense LAN port. I have tried rebooting the modem while OPNsense connected, restarting OPNsense while the modem is up and restarting them both. Never able to get an address.

If I connect the OPNsense WAN port to an internal LAN port, I do get an address via DHCP (192.168.0.x) and the LAN sets up as 192.168.1.x.

This was not a problem with pfsense on the same box or with my current ASUS router. What am I missing? I would welcome any suggestions.
Thanks!

[newsense]

How many ports on OPNsense ? Did you try connecting the WAN cable to those ports and see if you get an IP ?

[hish747]

4 ports. Tried the possible ports and as I wrote above, when I connect the WAN port to an internal LAN, I do get a normal LAN IP address. However, when I connect the same port to a cable modem, I get nothing.

[dseven]

Are you replacing an old router? A bit of Googling suggests that Cox like to limit you to specific MAC addresses. You might be able to get around that by spoofing the MAC address of your old router (WAN interfaces).

[someone]

Did you open ports 443 and 53 on the wan in the firewall rules on WAN, unblock bogons, then the modem or router should assign an address I would think

[someone]

Also most ISPs let you in via a mac address, if you change connected router probably will have to call them and put in the new device mac address

[newsense]

4 ports. Tried the possible ports and as I wrote above, when I connect the WAN port to an internal LAN, I do get a normal LAN IP address. However, when I connect the same port to a cable modem, I get nothing.

Try a different cable between modem and OPNsense.  If still not getting anywhere try setting the WAN port speed to 1GB - which is likely what's on the other end of the cable as well.

[hish747]

I really appreciate all the replies. However, can the problem really be the port/cable/mac address? If I install pfsense on the same box instead of OPNsense and use the same port & cable, I get a valid address from Cox.

[someone]

check firewall rules
Does your ISP use DHCP or a static IP
Both of those are settings