How to access the web interface of a router in bridge mode? - Page 1
Forum section: electronics / general

author: icafree
author_rank: Newbie
timestamp: August 17, 2025, 05:47:32 pm
content: T-Mobile 5G Box ODU This is an outdoor unit - a modem where the SIM card is inserted.Hello experts. My problem is that I wanted to minimize latency in my setup by putting the ODU into bridge mode using the MPDN Management settings. The APN name was "internet", and the IP type was "IPv4 & IPv6".This ODU is powered by PoE. The power supply has an "OUT" port (which goes to the ODU) and an "IN" port (from which traffic flows when the ODU is on). Initially, everything worked perfectly - the cable went to the router's WAN port, and the router provided internet access. When I connected the power supply directly to my computer, the PC automatically got an IP and had internet access.After I enabled bridge mode, the internet worked, but after a few minutes, the router lost its connection to the network (the 5G indicator went off), and only the power light remained on. It blinks every few minutes, probably because it can't connect to the network. It seems that enabling bridge mode also disabled the router's DHCP, and now my computer sees the network as "unidentified."I tried to manually set the default gateway and IP address to 192.168.0.1 (which I used to log in before this problem). It's worth noting that I could only access the settings viahttps://192.168.0.1/;just typing the numbers didn't work. Now, this doesn't work at all. I also tried 192.168.1.1 and 192.168.100.1, but none of them worked.Naturally, before all this, I tried a simple RESET. Unfortunately, it seems that bridge mode isn't reset. I've pressed the button for 10 seconds and held it for over a minute. I also tried holding the button while powering on the device - nothing helps. I cannot restore it to full factory settings.I thought I could find its gateway IP address to access the web interface and disable bridge mode, but the device is not sending any packets. I've tried using arp-scan and Wireshark.As I understand it, the most likely way to get out of this situation is to access the device's web interface, but the problem is that I can't find its address because DHCP is disabled. The device also has Bluetooth for configuration via a phone, but after scanning the QR code and trying to configure it, an error appears at the very beginning due to the lack of a SIM card connection. The SIM card is 100% functional and was working. Everything broke after I set it to bridge mode.I still hope for some hidden, strong factory reset option, that would also be a great help. I'm out of ideas.The device manual is here:https://www.t-mobile.pl/c/binaries/content/assets/lp/internet-5g-home-office/pdf/internet_5g_homeoffice_user_manual_odu.pdf

author: Halcyon
author_rank: Unknown
timestamp: August 18, 2025, 09:43:34 am
content: It depends on the router. It's not unusual that once you put a router into bridge mode, it disables everything, including the web GUI used for admin. Only a factory reset will bring that back. I have used some Dreytek routers, where the web GUI is still functional in bridge mode, but most routing, firewall etc... is disabled.If you're plugging in a modem (or router in bridge mode) directly into an end-user device (like a computer), then the WAN IP is essentially exposed directly to that device. It's a terrible idea! Don't do it! You want a router and basic firewall (at least) in between the modem and your devices. A router on your LAN should not introduce any noticeable latency at all.I'm also not familiar with how the USA does things. I wouldn't be surprised if your ISP disallow you from connecting "non-approved" devices to their networks, I've heard all kinds of horror stories.

author: icafree
author_rank: Newbie
timestamp: August 18, 2025, 03:27:23 pm
content: Yes, I understand that connecting such a modem in bridge mode directly to a computer is a bad idea. This modem comes with a router. The issue is, they both have a NAT function, and when I disable it, the internet seems to stop working. But when it's enabled on both devices, I end up with NAT type 3, which is why I wanted to remove at least one of these obstacles. Now I'm left with nothing at all...Maybe someone knows some hidden ways to factory reset the router, since the RESET button isn't working...?

author: icafree
author_rank: Newbie
timestamp: August 18, 2025, 07:39:22 pm
content: I apologize for the confusion. To put it simply, this is a T-Mobile Internet 5G Home Office kit, which includes an ODU and an IDU.I'm only interested in the ODU, as it serves as the modem where I can insert a SIM card to get internet access. Naturally, I want to connect it to the IDU, which can then distribute Wi-Fi. However, something in my head got mixed up, and I decided to test some settings, as I've always relied on the Reset button in the past.This time, it led to me putting the ODU into bridge mode, and now I can't reset it, nor can I access its settings to turn off this mode.Yes, I tried giving my computer the IP address 192.168.0.2 and pinging 192.168.0.1 - there's no response.Contacting T-Mobile hasn't helped either. They advise me to factory reset it, and when they understand that it's not working, they just suggest buying a new device.

author: Hogwild
author_rank: Regular Contributor
timestamp: September 01, 2025, 02:20:42 pm
content: If this gateway/modem is a rental as part of your ISP ToS, then it is extremely like that T-Mobile are obliged to find you a solution. That would be part of their contract. I would ask them to send me another device instead of going to all this trouble.

author: paulca
author_rank: Super Contributor
timestamp: September 15, 2025, 12:52:52 pm
content: The few modems I have had which did bridged broadband, the layer 2 bridge was VLANed. However that is location specific and in the UK most of ours goes via BT IP Stream and the "internet" is via VLAN 101.The older ADSL model, when bridged, just did a literal bridge connecting all of it's interfaces into one bridge. So I had public layer two traffic along side the web interface and for it to work the modem needed to be on the RIPE range assigned to me and thus public. Not ideal. This is why you don't use £50 routers on production sites.My Vigor VDSL modem the web interface appears on VLAN 1. It had it's default 192.168.0.1 address. This conflicted, but as it was out side the firewall it needed NAT anyway, so I made it to a free range 192.168.1.0/24I don't know how T-Mobile do their gateway boxes though.How would you find it? Not that easily without the IP. You can tcpdump or wireshark the link and look for traffic, if you get lucky and it's broadcasting you can get it's MAC and/or IP. Beyond that you get into Kali-Linux territory with arp scans, arp cache floods etc. To force everyone on the link to identify.Bail out plan?Most routers have a hardware reset mechanism. It usually involves you holding the button in for 30 seconds, then while still holding, power cycle the device and continue to hold. This will usually reflash the config with the factory default. Different vendors differ. Some for example want you to power cycle it 5 times at a 10 second interval. The manual is your friend.

author: madires
author_rank: Super Contributor
timestamp: September 15, 2025, 01:59:33 pm
content: It depends on the specific router model. Some keep their LAN address, sometimes on a specific ethernet port or VLAN. Others drop IP completely and do only bridging (requires factory reset for configuration changes, and switching back to bridge mode again). There's also no general rule for modems. Some modems have an IP address, sometimes hidden (not noted in the user guide).