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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...
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.
CrimpOn
Thank you for your response.
I ran
ipconfig /all | find /i "DHCP Server"and received a single row response
DHCP Server . . . . . . . . . . . : 192.168.0.1
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?
This was an example of documenting multiple DHCP servers on a network. Although the topic of "how to find rogue DHCP servers?" has been around for a LONG time, there appear to be few options. When I tried using the Windows feature on my computer, it failed to report ANY DHCP servers at all, even though there obviously is one.
As a test, I deliberately set up a DHCP server and used a packet capture program (Wireshark) to record what happened when the PC asked to renew the IP assignment. Sure enough, DHCP offers were recorded from the Orbi router and from this other DHCP server. Thus, a packet capture process appears to document "who is out there serving DHCP?"
Wireshark is free for Windows, Mac, and Linux.
Internet search finds other programs specifically devoted to documenting DHCP servers on a network, but when I tried to download them, most are no longer available.
Since it is impractical to turn off all 30 devices, it is probably NOT one of the devices which has been assigned an incorrect IP address.
I am still confused about how these devices show up in the Attached Devices display. Does the Orbi actually display them with that rogue IP address?