I have a misbehaving firewall device that I’m going to have to take offline until a replacement arrives. I’ll be stuck depending on the firewall in the ISP modem. (Bother). I need to minimize the downtime while I reconfigure the modems LAN IP address.
I want to change the LAN address of the modem to be the same as the LAN address of the bad firewall and turn off the modems DHCP serving. Then unplug the modem from the firewall device WAN port, and unplug our network from the firewall LAN port. Then plug the network directly into the modem LAN port. On our internal network DHCP is served from another server and not the firewall device.
Is there any reason that this won’t work? I figure that network downtime while I unplug and plug in cables to be about 30 seconds.
Incidentally, the problem with the firewall device is that it is occasionally disconnecting from the modem without the modem or firewall logs shedding any light as to why. Our ISP has already replaced the modem without solving the issue. We’re a church and have a major event streaming in a few days. The connection cannot be allowed to drop during the event!
