Cannot Connect To Roundcube Webmail. Various Errors On Login With RAX120 Router.

[BelowTheBelt]

Router:  Model# RAX120-100NAS   AX6000

Gateway/Router To Internet:   TMobile 5G Gateway

Incompatible/Problem:  Cannot Login To Roundcube Webmail with router connected to gateway

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I have TMOBILE internet services provided via a 5G Wireless gateway.

Without the RAX120 connected via ethernet to the gateway, I can connect to my Roundcube Webmail service without issue.

However, the 5G Gateway does not offer USB drive support.   As a result, I added the   RAX120-100NAS   for network drive support.

Almost all is good.   I can connect to:

Network Printer

Streaming Services

Gmail

Ymail

Network drives.

ISSUE

I cannot login to ROUNDCUBE webmail services with RAX-120 connected to gateway.  

From my laptop, I can connect if I:

1.  Switch from RAX-120 WIFI connection to my mobile hotspot, I can login. 

2.  Remove RAX-120 ethernet connection to gateway, and wifi to gateway, I can login.

3.  Disconnect my wifi connections and utilize my laptops modem, I can login.

I have tried all 3 browsers:

1.  Edge

2.  Chrome

3.  Firefox

I have tried another laptop.

All to no avail.

These are the 2 error messages I receive ONLY WITH THE RAX120 connected to the gateway:

[michaelkenward]

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@BelowTheBelt wrote:

Router:  Model# RAX120-100NAS   AX6000

Gateway/Router To Internet:   TMobile 5G Gateway

Incompatible/Problem:  Cannot Login To Roundcube Webmail with router connected to gateway

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It sounds like you are piling router on router. That is an invitation to chaos.

Two routers on your network can cause headaches. For example, you can end up with local problems with addresses on your network. Among other things, the other router can misdirect traffic to addresses that the Netgear router usually handles, such as routerlogin.net or the usual default IP address for a router, 192.168.1.1.

I suspect that this is what gets in the way of your webmail services.

This explains some of the other drawbacks of NAT conflicts.

What is Double NAT? | Answer | NETGEAR Support

It is often easiest to use just one router and to set up the second router as a wifi access point (AP) with a wired connection to the main router. Netgear advises this, as does just about every site you will visit.

How do I change my NETGEAR router to AP mode? | Answer | NETGEAR Support

But that has its own drawbacks:

Disabled Features on the Router when set to AP Mode | Answer | NETGEAR Support

It may be possible to put the modem/router into modem only (bridge) mode and then to use the second device as the router.

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Just another user with time on their hands.

[BelowTheBelt]

In an attempt to troubleshoot, my friend lent me an older TP Link Router....Archer C90 AC1900.

This worked like a champ right from the get go.  No issues with any webmail site.  No issues with access to the network storage.

So, maybe I am sticking with the TPLINK router and sacrificing some speed.

[FURRYe38]

I would give the DMZ on the host gateway router a try with the RAX120 and see if this helps. 

Your double NAT condition will impact how the RAX120 and your web mail services work in that condition which should be avoided, either by using the DMZ or in AP Mode with the RAX120. 

[0i]

I am not an expert in these matters, but i am also not a novice.   Nevertheless...

1.  I do not know what DMZ ON THE HOST GATEWAY ROUTER means.   I have tried to disable WIFI on the gateway, but my gateway does not provide this option.   Apparently the 5 GHZ band must be up on "reboot" or the router hangs, so the disabling feature of wifi is disabled.

2.  I do not know what AP MODE on the RAX120 means.  

In the past, I would login to my routers via a browser.  Unless I am mistaken, there is no browser interface for the RAX120, and only the app(in my case Android) can be used for a connection.

If it is correct the APP is my way into the router, I can tell you the app is crap. Although all of my PC's find the RAX120, my Android finds the RAX120, the APP has a hard time and typically shows the router as being connected to the app.   My best chances so far with the app have been to uninstall, than reinstall and start from scratch.   Suggestions in this regard would be appreciated.

[michaelkenward]

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@0i wrote:

1.  I do not know what DMZ ON THE HOST GATEWAY ROUTER means. 

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DMZ is one of those terms thrown around by people who assume that everyone else knows all about networks. My take is that this stuff should be easy, and we need clear and simple explanations of what that stuff means.

This longish piece has a reasonably clear explanation of what we are talking about:

How to Use Your Router and ISP’s Modem/Router Combo In Tandem

I have done the DMZ thing with the modem/router that my ISP (BT in the UK) supplied. That does not allow me to use it in modem-only (bridge) mode.

The key is to set up the ISP's device with a local IP address that does not clash with whatever you have the Netgear router on. That is usually 192.168.1.1.

By default local IP address my modem/router squats on 192.168.1.254. That clashes with the Netgear router. I wanted to keep 192.168.1.1 for everything already on my local network. All those fixed and reserved 192.168.1.XXX addresses.

I set my modem/router to use 192.168.2.1 as its local IP address.

After I connected things and rebooted the network, I went into the modem/router and looked for the IP address it had allocated to the Netgear router.

Use that IP address as the DMZ address in the modem/router. (You'll have to find out where that setting is for your device.)

Then you can set the Netgear on 192.168.1.1.

Since doing that all has been well. No conflicts between the two routers.

I have turned off the redundant wifi from the modem/router. It is odd that you can't do that, but you can always give the wifi settings that don't clash with the Netgear's.

Both routers are accessible using the a web browser and the graphical user interface (GUI) aimed at their IP addresses. So you can get into them and play with their settings with wrecking everything.

This is from memory a few months ago. It still works, but you may have to tweak if for your setup. You should also read the article at the end of the link above.

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Just another user with time on their hands.