How do I change my default gateway IP address?

[dassub]

So, a big issue here that I hope can be resolved.

My small business has its Window Server domain and DHCP set up in the 192.168.100.x  range.

There are 20+ devices that use this range, including some set as static IPs, and some port forwards for things like remote surveillance camera access.

When we had Bell internet, our Linksys router worked just fine set up as 192.168.100.1 (we have several models of them that we tried).  Our server has the gateway set up to look at 192.168.100.1.

Now that we have switched to Rogers, the gateway reserves all LAN IP addresses in the 192.168.100.x range.  I tried in Bridge mode and our router, and the router chokes on the IP conflict and assigns itself a different LAN IP.  I tried in Gateway mode but it doesn't let me assign itself in the 192.168.100.x range at all, it says it's reserved.

As you can see, I'm in quite the jam.  I don't want to change the entire Windows server domain to a different subnet to resolve this issue.  Ideally I want to run in Bridge mode and let my own router use 192.168.100.1 as it was before.  Worst case, I thought that I could use the Rogers modem in gateway mode and assign it 192.168.100.1 and open the ports etc from there, but obviously that didn't work.

So, what can I do?  Is it possible that Rogers can exempt my small business's location from the 100.x restriction?  Thankfully for now, we're up and running because a very very old Linksys router chooses to ignore the IP conflict and carry on business-as-usual, but it's old and only has 100mbit ports, while we are paying for gigabit.

Any advice would be greatly appreciated.

***Added Labels***

[RogersAndy]

Hi @dassub!

Welcome to the community!

Sorry to hear you're having issues with your business network setup! I can appreciate wanting to ensure that the necessary subnet is in use to avoid any major changes. I'll provide as much information as I can. Perhaps the others within the community may be able to provide some additional insight.

Can you confirm for me if you're using a residential or a business service? Reason I ask is that with a residential there are modem default gateway address limitations. If you're using a residential account it may be worth it to speak with a Rogers business representative to discuss getting a managed router.

@RogersAndy

[dassub]

Hey there @RogersAndy .

This is a business service.

But, I do notice that it uses the same white Gigabit Wi-Fi Modem that I also have for my home Internet service, which is also Rogers gigabit, but on an entirely different account that's residential.

I've tried to re-create the same scenario at home, and it acts the same way, it kicks off my router when I try to use 100.1, so it's definitely reproducible both at home and at the business location.

Edit: Just so I'm more clear, this is a business service under a business account.

The topology is:

Rogers modem in bridge mode > Router with DHCP disabled and some ports forwarded > Switch > Clients | Windows Server 2016 as the DHCP in the 192.168.100.x range.

I'm willing to remove the router and use the gateway mode, IF I can use 100.x so I can forward the ports I need open.

It would be very very expensive to change the business to not use the reserved subnet of 100.x because it's been set up this way for over a decade (before we signed up for Rogers internet).

[-G-]

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@RogersAndy wrote:

Sorry to hear you're having issues with your business network setup! I can appreciate wanting to ensure that the necessary subnet is in use to avoid any major changes. I'll provide as much information as I can. Perhaps the others within the community may be able to provide some additional insight.

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Don't the Hitron modems route connections to 192.168.100.0/24 internally so that users can connect to 192.168.100.1 to access the modem/gateway's admin UI even when it is in bridge mode?  I'm pretty sure that this is hard-coded and I don't know of any way to change or disable this.

[dassub]

Does Rogers offer a modem that doesn't exhibit this behavior?  A simple modem with no gateway functionality at all?

It would be way too expensive in terms of cost and time to change our business LAN IP/subnet range.

I'm hesitant that calling technical support would even be able to help in such a situation, since this seems to be a reserved LAN IP space as a hardware limitation.  Ideally we'd need some exemption, if that's even possible.

[-G-]

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@dassub wrote:

Does Rogers offer a modem that doesn't exhibit this behviour?  A simple modem with no gateway functionality at all?

It would be way too expensive in terms of cost and time to change our business LAN IP/subnet range.

I'm hesitant that calling technical support would even be able to help in such a situation, since this seems to be a reserved LAN IP space as a hardware limitation.

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The XB6 gateway does not use 192.168.100.0/24 internally; it uses 10.0.0.1 for its admin web UI while in bridge mode.  However, I don't know if this device is available to business accounts.  It was designed by Comcast to be the hub for their Connected Home offerings.

FYI, many cable modems, including pure modems with no gateway functionality (used by TPIA providers) also route connections to 192.168.100.1 internally so that users can log in to view signal levels and error stats.

[dassub]

Interesting information about cable modems, thanks. All my home cable setups use 1.1 so I never encountered it. Our business used Bell internet for a decade, so the issue never occurred.

[dassub]

I guess my obvious next question is if anyone here has an XB6 and can confirm that you can use 192.168.100.1. Either with your own router while in bridge mode, or assigning it that LAN IP while in gateway mode.

It's likely easier to argue for a hardware exception if I know it would actually resolve my issue first.

[-G-]

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@dassub wrote:
I guess my obvious next question is if anyone here has an XB6 and can confirm that you can use 192.168.100.1. Either with your own router while in bridge mode, or assigning it that LAN IP while in gateway mode.

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Actually, I am currently (temporarily) using 192.168.100.0/24 on my internal LAN without any issues.  Granted, I do not run an Internet-accessible server farm, VPN server, or anything else that you would see in a typical business so this may not be confirming very much.

I think that it would be better (and easier) to see if Rogers can either change the "bridge mode" provisioning for your CODA modem or inquire if they have any other suggestions or recommendations on how this addressing conflict can be resolved.  The XB6 is rather quirky (to put it kindly) and I would try to avoid using it if at all possible.

[dassub]

I appreciate you doing some of the legwork for me.  Are you using bridge mode and your own router, or are you able to assign the XB6 the 100.x LAN address?

Our business only uses router rules to forward a few ports for the surveillance cameras.  No VPN, and most of the heavy lifting re: network management is done in Windows Server.

Sounds like I'll need to contact rogers tech support eventually, unless they can directly reach out to me from here (since there's more obvious context in this post than I can describe verbally).

[-G-]

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@dassub wrote:

I appreciate you doing some of the legwork for me.  Are you using bridge mode and your own router, or are you able to assign the XB6 the 100.x LAN address?

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No problem.  Actually, I have been in this configuration for the last few days, by happenstance, for a completely different reason.  As I said before, I have not run into any issues from an IP routing perspective.

Yes, my XB6 is in bridge mode, and I use my own router, and I support users in the Community who also wish to use their own router and 3rd-party network gear with Ignite TV.

Our business only uses router rules to forward a few ports for the surveillance cameras.  No VPN, and most of the heavy lifting re: network management is done in Windows Server.

Sounds like I'll need to contact rogers tech support eventually, unless they can directly reach out to me from here (since there's more obvious context in this post than I can describe verbally).

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The XB6 is a primarily residential device and was designed to be the hub for a "Connected Home".  It's an all-in-one gateway with special support for Ignite TV, Home Phone, and Home Monitoring services.  It also supports Parental Controls, Protected Browsing, and has integrated support for Ignite WiFi Pods, and all this can be managed through a mobile app.

Your setup probably will work, if you use your own router and with the XB6 in bridge mode.  However, I still strongly recommend sticking to a solution that is fully supported by Rogers for their business customers.  I don't think that anybody from Rogers will follow up with a post here but feel free to reach out to @CommunityHelps  -- click on the username link, then click on the "Send this user a Private Message" button.  They can open a support ticket on your behalf and consult with other experts internally to find a more viable solution for you.

[dassub · Accepted solution]

So for anyone who ends up Googling this issue and finding this post, the resolution is that there really isn't anything that can be done on Rogers end, and no router hardware will cooperate with the 192.168.100.1 LAN IP.  The only hardware that might support it (XB6 from this thread) is unavailable to business customers.

The resolution is that we have reached out to our IT vendor to change our LAN IP, along with our Windows Server DHCP scope, etc.  It's a costly and timely solution, but ultimately the only solution.  This entire situation could have been avoided had our (different) IT vendor not chosen this LAN IP over a decade ago, but that's just how it goes sometimes.