DHCP Lease with Cable Modem

[IPOfficeNewUser]

I am using the IP Office 500 as the router with Cable Modem. It does not renew the DHCP lease. Once the lease expires, I lose the connection if the modem changes my IP address. I need to restart my IP Office to get the updated IP Address. Any thoughts ?

 

[ProviderReborn]

Put the IP Office on fixed IP and add all the DNS settings under the system tab.

ACA - IP Office Implement
ACA - IP Telephony
ACS - IP Office Implement (Aug 30th)

 

[IPOfficeNewUser]

My Cable Modem gives out IP Address through DHCP. If I put IP Office on fixed IP, the modem is going to change the IP on its own.

I think the problem is with IP Office. It does not bother to look at the expiry time and renegotiate the IP address

 

[tlpeter]

I think you need to buy a good modem instead of this one


ACA - Implement IP Office
ACA - Voice Services Management
______________
Women and cats can do as they please and men and dogs should relax and get used to the idea!

 

[SuperJenks]

I dont think there is any mechanism for the IPO to know that the IP has changed. It works like a pc. A pc will hold the dhcp address until it is changed manually or the system is rebooted.. IPO works the same. It should be set to client mode under dhcp settings in system>lan1 tab.

 

[ProviderReborn]

I would make you IP Office the DHCP server and get the IP office to route to the gate way (Cable Modem)

Then the PCs will get the lease off the IP Office and the IP Office will route to the Modem.

Again the IPO is not an ideal DHCP but least that way you will not get your above problem.

ACA - IP Office Implement
ACA - IP Telephony
ACS - IP Office Implement (Aug 30th)

 

[DavidCT]

IPOfficeNewUser,

DHCP Clients (the IPO) are suppose to go back to their DHCP server (Cable Modem) and ask to renew their lease half way through the lease duration. So if your cable modem issues a DHCP lease with an expiration of 24 hours, then at 12 hours the DHCP client should ask to renew.

I presume you have the WAN/LAN2 port of the IPO on the Cable Modem and set as DHCP Client, and the LAN1 port of the IPO going to your LAN Switch?

Where are you located? In my area cable modems use DHCP, but the IP address never changes unless the device plugged in to the modem changes (thereby the modem seeing a new MAC address).

If it becomes a big problem, stick a NAT Firewall/Router in between the IPO and the Cable Modem and let the Firewall/Router deal with the DHCP on the Cable Modem... our get a Static IP if available.