SB6141 Internal Network IP Address Question

[icericedice]

I have to be missing something simple...
I have a new SB6141 for replacing my comcast rental modem.
Easy to switch it out and get working, but what I can't figure out is how to change the default internal IP Address (default is 192.168.100.1). My internal network has a bunch of static assigned IP addresses for various programs and automations I have. Re-IPing my LAN will be a lot of work.
I find it hard to believe that one can't change the address (I need it in the 192.168.0.X range). However when I connect to the management console, it seems to be __read only__. There was no login challenge for authentication either. One of my first moves with any equipment I install is to change the password and set the IP address to what I want for my LAN. I see no way to do either in the management console. Is that just how it is, or am I missing something? I think I have to be missing something.

Since these devices are so popular, I'm hoping someone else may have some wisdom that I am missing.

Other details that may not matter: For the management console I was connected directly from a laptop to the modem by ethernet cable. I tried various browsers, in case the system required some specific browser - Edge, Chrome, Firefox. Laptop is a few year old enterprise grade HP running Win10. I read the user guide, it mentions nothing about changing the IP address.

 

[BuddhaSkoota]

I have to be missing something simple...
I have a new SB6141 for replacing my comcast rental modem.
Easy to switch it out and get working, but what I can't figure out is how to change the default internal IP Address (default is 192.168.100.1). My internal network has a bunch of static assigned IP addresses for various programs and automations I have. Re-IPing my LAN will be a lot of work.
I find it hard to believe that one can't change the address (I need it in the 192.168.0.X range). However when I connect to the management console, it seems to be __read only__. There was no login challenge for authentication either. One of my first moves with any equipment I install is to change the password and set the IP address to what I want for my LAN. I see no way to do either in the management console. Is that just how it is, or am I missing something? I think I have to be missing something.

Since these devices are so popular, I'm hoping someone else may have some wisdom that I am missing.

Other details that may not matter: For the management console I was connected directly from a laptop to the modem by ethernet cable. I tried various browsers, in case the system required some specific browser - Edge, Chrome, Firefox. Laptop is a few year old enterprise grade HP running Win10. I read the user guide, it mentions nothing about changing the IP address.

Your router should be managing DHCP, so there should be no need to change the IP scheme of your LAN or change the modem GUI address.

The modem IP 192.168.100.1 is used only to view its GUI. The modem should only be providing the public IP to your router.

 

[icericedice]

They don't see each other because the router's ip range is 192.168.0.X and the cable modem is preset at 192.168.100.1. If the cable modem is set at an internal address at 192.168.0.2 (like my current rental), they can communicate.

 

[BuddhaSkoota]

They don't see each other because the router's ip range is 192.168.0.X and the cable modem is preset at 192.168.100.1. If the cable modem is set at an internal address at 192.168.0.2 (like my current rental), they can communicate.

Not clear about what you mean by "don't see each other". Is your router not getting the public address, or are you just not able to access the GUI from your LAN?

If it's simply a GUI access issue, that wouldn't affect LAN-WAN connectivity.

I am able to access my modem at 192.168.100.1 from 192.168.1.x, so it may be that your router is not directing devices to private addresses via WAN.

 

[icericedice]

For example, I can't ping from a 192.168.0.X device to the cable modem at 192.168.100.1, so no internet access either.

Since you are experienced with the modem in question, can one change the internal IP? Is it fixed in the firmware?

 

[BuddhaSkoota]

For example, I can't ping from a 192.168.0.X device to the cable modem at 192.168.100.1, so no internet access either.

Since you are experienced with the modem in question, can one change the internal IP? Is it fixed in the firmware?

The internal IP is fixed on mine, but this is dependent on the ISP. Your ISP may push a configuration change that allows or prevents addressing changes.

My understanding is that the 6141 does have a DHCP server, but this isn't implemented when on Comcast service.

Was your rental modem configured with DHCP enabled, and you are not using your router as a gateway?

Did you reboot your router after connecting it to the new modem?

 

[icericedice]

The rental modem allows full configuration. I had reset the IP address to a 192.168.0.X address and turned off its DHCP, as I used the DHCP on my wireless router. Thanks for the info, sounds "impossible" to do what I want. I did try to talk to comcast about the firmware capabilities, but none of the drones working there has any idea how things work and just kept saying the manufacturer must be contacted, even though comcast pushes the firmware. Tried multiple calls and chats with the same reaction. OEM no help, because comcast controls the firmware - which makes perfect sense to me. I guess I have three choices: (1) Re IP my LAN, (2) Keep renting the current modem, or (3) establish some type of gateway to link the 192.168.0.x subnet to the 192.168.100.x subnet. I'd need to do some research on #3.