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RBR40 and RBS40 generate different subnets for attached devices
I use RBR40/RBS40 mesh. Despite the fact that I have defined the subnet (192.168.0.x) for the LAN TCP/IP and directed to use Router as DHCP server with the starting and ending IP addresses within the same subnet, somehow the wireless devices connected to the LAN get not only the addresses in the abovementioned range, but also in the range of subnet 172.27.35.x.
Why is this, and how I may prevent it from happening?
I have found the "rogue" DHCP. My VoIP device had the internal DHCP server enabled. I turned it off, and the issue went away.
Thank you very much for your help.
16 Replies
Does the RBS show fully synced to the RBR on the RBRs web page?
Has a factory reset and setup from scratch with a wired PC and web browser been performed?
https://kb.netgear.com/22697/How-do-I-install-my-NETGEAR-router-using-the-router-web-interface
Might try this with the RBS in same room or near the RBR and setup from scratch using this process:
Fully Sync means the status shown on the RBRs web page shows GOOD or Wired for RBS that are ethernet connected.
Can you log into the RBS web page at it's assigned 192.168.0.# IP address?
Which devices are getting the different IP address from 192?
What Firmware version is currently loaded on the RBR and RBS?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?
PFi wrote:
FURRYe38
Thank you for your response.
I am not sure what the "fully synced" means. The attached devices tab shows devices connected to both the router RBR-40 and the to the satellite RBS-40. Moreover, the devices with IP addresses from both subnets appear connected to both router and satellite.
There are several groups of IP addresses reserved for private networks:
https://en.wikipedia.org/wiki/Private_network
The most common reason for this is another DHCP server on the network. When devices broadcast a DHCP request, they accept the first response.
Is is always the same devices that get the unexpected IP address? Do they have anything in common (such as all being Sonos speaker units)? Do they sometimes get the expected IP address?
Testing this hypothesis is not trivial. This article presents some options:
https://serverfault.com/questions/8526/how-do-i-find-if-there-is-a-rogue-dhcp-server-on-my-network
Probably the quickest is to disable the router DHCP service temporariliy and see if devices continue to get IP address assignments.
PFi
- Turned on DHCP server on a Raspberry Pi on the network Using a DHCP pool of 192.168.1.201 to 192.168.1.251 The Pi has two network interfaces: 192.168.1.29 (WiFi) and 192.168.1.30 (Ethernet)
- Started Wireshark to capture every packet going through my PC's Ethernet port.
- Ran the same command (
ipconfig /all | find /i "DHCP Server"and got NOTHING. - Then I ran the command ipconfig /renew, and Wireshark recorded this:
The Orbi (192.168.1.1) and both Raspberry Pi network connections responded with DHCP offers. Because the Orbi offer was received first, it was the one the PC accepted.
-
So, I am somewhat at a loss to understand the situation. (Like, why does that command work for you and not for me.) Most of the internet hits I got on searching for DHCP servers are at least 10-12 years old. (There were a bunch of programs written about 2009!)
These devices with the strange IP addresses:
- They have only a single network adapter?
- They show up in the Orbi Attached Devices list only once?
- This strange IP address shows up in the Orbi Attached Devices list?
