IP Conflict... GL-AR750S

Technical Support for Routers
1

Problem, devices connected to the Cisco 240AC have internet (via the WiFi bridge), but devices can not see/communicate with one another. When I connect to the Cisco CBS350 via ethernet cable, I can reach other devices and also reach the switch on 192.168.1.254. The switch only has 1 vlan (VLAN 1)

Cisco CBS350 Switch (192.168.1.254)

∟ Cisco 240AC (01.84.9a.40.e0.48.ae | 192.168.1.1) <-> Wireless devices on the network

∟ GL-AR750S WiFi Bridge using OpenWrt 18.06.1 (94:83:C4:0C:6B:62 | 192.168.8.1) <-> Starlink Router <-> Internet

∟ Other devices such as PoE cameras, NAS, TVs…

I have not made many settings changes on the CBS350 switch other than:

The WiFi Bridge web interface can be accessed via http://192.168.8.1/, which I don’t entirely understand. The 192.168.8.1 is the default that the bridge uses – and it works somehow.

I am fairly certain that the WiFi bridge is the culprit. My laptop, when I’m connected to the Cisco AP, has an IP address of 192.168.8.110 which it shouldn’t if it got the IP address from the Cisco CBS350 which is on 192.168.1.x.

2

It sounds like you have 2 DHCP servers on the network, with the Cisco CBS350 running one DHCP.

I am unclear on how you have set up the GL-AR750S as a “WiFi Bridge” and what is the Network mode (see Admin Panel → MORE SETTINGS → Network Mode). If it is in “Router” mode and WWAN is connected as Repeater to Starlink, then it would be running DHCP also.

I do not work for and I do not have formal association with GL.iNet

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3

Thank you for your help! I REALLY appreciate it.

The device is in “router” mode, should I change it to another mode?

And I’m pretty sure I figured out how to disable the DHCP server on the GL-AR750S. It didn’t solve the issue, but having multiple DHCP servers on the network… seems like a bad idea in any case.

2022-09-02 at 5.57 AM
2022-09-02 at 5.57 AM1183×877 102 KB

4

Is there a specific reason to run DHCP server on the Cisco CBS350 managed switch? The DHCP server normally runs on the network gateway, which is the GL-AR750S in your setup.

To disable DHCP server on the GL-AR750S, go to LuCI → Network → Interfaces → LAN → Edit → DHCP Server → General Setup → turn on “Ignore interface”, then restart.

If you temporarily turn off DHCP on the Cisco CBS350 and client devices are still getting IP addresses, then there is another DHCP server still running.

5

I like the GL-AR750S, but it’s not anywhere near as robust as a Cisco Switch. I can’t have the GL-AR750S be “responsible” for all the IP address assignments… the security cameras, the boat-data gateway, the navigation data access, the TVs… that’s really something the cisco switch should take care of.

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