C7800 doesn't like LAN Range IP change

[MMC2019]

I have a customer with a C7800 modem/router.    I have a large amount of network gear there, so I changed the LAN IP range to 192.169.1.x.   The router default was 192.168.0.x.    When I change it,   I cannot get into the router via the new IP address locally, but with remote management on,  I can get in from outside the network via my hotspot.

Like any other router I've worked with,  you change the LAN range and you are done.  This thing doesn't seem to like the 192.168.1.X address range and I really don't want to change all the static IP addresses that I have in place. 

Tonight, the router failed, or at least I cannot access it remotely, and anything online has stopped.   Might be a Comcast issue, but the issue with the LAN address puzzles me.

[antinode · Accepted solution]

> [...] router no longer accessible locally via the 192.168.1.1 address,
> [...]

   Regarding "no longer", see "not a useful problem description", above.

>    After you changed whatever you changed, did you restart the
> (unspecified) computer where you were doing this work?  What is its IP
> address?

   Still mysteries.

> [...] should not be required to do so. [...]

   I agree, but that doesn't answer any of the pending questions.

[MMC2019]

Can't figure out how to edit post.   The range that I prefer is 192.168.1.x.  Not as I posted above.

[antinode]

> [...] When I change it, [...]

   What, exactly, did you change, from what, to what?

> [...] I cannot get into the router via the new IP address locally,
> [...]

   "cannot" is not a useful problem description.  It does not say what
you did.  It does not say what happened when you did it.  As usual,
showing actual actions (commands) with their actual results (error
messages, LED indicators, ...) can be more helpful than vague
descriptions or interpretations.

   After you changed whatever you changed, did you restart the
(unspecified) computer where you were doing this work?  What is its IP
address?

> [...] This thing doesn't seem to like [...]

   "seem"?  "like"?  See "not a useful problem description [...]",

above.

[MMC2019]

Changed the default LAN range to 192.168.1.x.    Gave the router an address of 192.168.1.1,  router no longer accessible locally via the 192.168.1.1 address, but IS accessible if I connect outside of the network, using the external WAN address and port to connect to the web gui.

Router does not function correctly when using this LAN range.    I have 23 devices that have static IP addresses,  would prefer to not have to change everything over, and should not be required to do so.    Advised customer to get rid of this router and get a better one.

[antinode · Accepted solution]

> [...] router no longer accessible locally via the 192.168.1.1 address,
> [...]

   Regarding "no longer", see "not a useful problem description", above.

>    After you changed whatever you changed, did you restart the
> (unspecified) computer where you were doing this work?  What is its IP
> address?

   Still mysteries.

> [...] should not be required to do so. [...]

   I agree, but that doesn't answer any of the pending questions.