Router ip address resets to 192.168.1.1

[CockneyUSA]

Every now and then my router resets to 192.168.1.1

I get a message when I get back into it that there was an ip address conflict with my ISP. I have been usiung the 192.168.100.x range for many years and this is the first time I've seen this. It runs fine for weeks and then ... reset... I change it back to the 192.168.100.x subnet and it works fine again for several weeks.

Any ideas?

A

[Mars Mug]

The IP address range 192.168.100.x is used by many cable modems as a default range when contact with the ISP may be lost, or for configuration of the modem (typically at 192.168.100.1). When the Netgear router detects that range on its WAN (Internet) side if you have already configured the LAN for the same range then there will be IP addressing conflicts. That’s why the router automatically changes the LAN side subnet.

[CockneyUSA]

Thank you, that is usefull to know. This is the only router to pick that up.

I'll check my modem to see what address it's using. You say it only uses this address when the cable connection drops?

A

[Mars Mug]

Normally yes, when that happens the modem will typically allocate an IP address from the same range to the connected computer e.g. 192.168.100.2. So if a router is connected which has already been configured to use that range on the LAN side then there will most likely be clashes.

Otherwise, the modem can be accessed at 192.168.100.1, but you may need a direct connection from the PC to the modem to do this.

[jmizoguchi]

simply check the WAN IP of the router under router status.

usually if this is cable modem, it will always pushes public IP so using same LAN subnet as cable modem device IP such as 192.168.100.x may effect but should not although issue may coming from when ISP has technical difficulties, your WAN IP may becomes 192.168.100.x therefore netgear router is avoiding conflict from WAN and LAN IP subnet becomes same.

simply avoid using common subnet on router's LAN subnet.
below are few of commonly used IP with may devices

192.168.1.x
192.168.0.x
192.168.100.x
192.168.254.x
10.0.0.1
10.10.10.x