I'm attempting to connect a NV 1335 to a Charter/Spectrum cable modem Arris Tm1602. This is just a modem, not a router, so there are no settings in it. I previously had a Netgear router connected to the modem, and it retrieves the dynamic IP from the modem just fine. I then reboot the modem, connect the 1335, and it will never get an IP address.
- Rebooting and reconnecting the Netgear or a laptop will retrieve an IP address, so I know the modem is working.
- Plugging the designated WAN port from the 1335 into a LAN port on the Netgear will retrieve an IP address, so I know my config on the 1335 is working.
A couple of interesting things:
- This modem allows access for viewing of status on a local IP, 192.168.100.1, though you can't change any settings. This in spite of the fact that when you connect to it via a laptop, you are assigned the external IP.
- On rare occasions of rebooting one, then the other, modem and 1335--I tried for hours yesterday--I did get it to show an IP in the AOS web GUI of 192.168.100.x (it varied), but it never showed Bound.
When I ran "debug ip dhcp client vlan 2", it showed that the DCHPDISCOVER would be sent, but the DHCPOFFER would never be received. Then when I plugged it into the Netgear, it did receive the DHCPOFFER and the rest of the negotiation. I never caught the times it got a 192.168.100.x, but I assume it got the offer but not the rest of the negotiation.
The question is, based on the apparently odd way the Arris modem is set up, is there something I can change in the 1335 setup to accommodate this and make the DHCP work?
Relevant config snippet:
interface gigabit-switchport 0/1
no shutdown
switchport access vlan 2
!
!
interface vlan 2
description Public
ip address dhcp
ip mtu 1500
ip access-policy Public
ip crypto map VPN
qos-policy out vlan2QosWizard
no awcp
no ip route-cache express
no shutdown
