Strange System Log

[xMaN73]

I've noticed in my System Log, I've been getting this every 5 minutes. I tried to search by MAC and can't find a vendor and my ASUS RT-AC68U is on fw 384.17, running FreshJR QOS. Anyone know what that is? BTW, my router is using MAC filtering so it won't dish out the DHCP IP below to that MAC device. Thanks for any info!

Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d

 

[Zastoff]

I've noticed in my System Log, I've been getting this every 5 minutes. I tried to search by MAC and can't find a vendor and my ASUS RT-AC68U is on fw 384.17, running FreshJR QOS. Anyone know what that is? BTW, my router is using MAC filtering so it won't dish out the DHCP IP below to that MAC device. Thanks for any info!

Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:45:30 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPDISCOVER(br0) 00:45:b9:26:54:8d
Jun 4 10:50:33 dnsmasq-dhcp[241]: DHCPOFFER(br0) 192.168.1.30 00:45:b9:26:54:8d

This may help:
LAN/DHCP-server: Hide DHCP/RA queries =Yes

 

[xMaN73]

This may help:
LAN/DHCP-server: Hide DHCP/RA queries =Yes

Hmm...that's one way around getting those messages filling my system logs but I won't be able to see the other requests if I need to reference.

 

[jpthsd]

looks for that ,,,every 3s with those DHCP request/offer ...it happened to me quiet years ago on AC68U from Zmodo NVR. My case was severe every 1s with many of those logs generated UNTIL router admin site inaccessible. For some reason I did years ago, the Zmodo NVR stopped sending out the DHCP requests.

Now it happened two days ago with my new AC86U as router (DHCP server of course). Twice, it took the admin portal of AC86U inaccessible. I had to disconnect that NVR, enough for so long 3 years of operation NVR/wifi security camera system.

Now it's happening from the MAC,,,this problem needs to be taken care of or your router's admin will be inaccessible.

I know for sure this issue isn't from the Router's DHCP server but DHCP client! You might try reserve assignment for that IP address to that MAC, (mine didn't work but your case is MAC computer,,,perhaps it would work!)

 

[xMaN73]

Here's a monkey wrench. I allowed that MAC address to pickup the IP that the DHCP was trying to dish out but it never picked it up. I looked in my DHCP server of manual IPs being dished out and it's not in there either. I continue to get that message every 5 minutes on the dot.

I guess I could factory reset my router and see if it was a previous setting that was in there that never got cleared or showing in the GUI. If I run a backup, factory reset, and then restore, will it bring it back? Hmmm...

 

[ColinTaylor]

I'm not sure what you mean by "have it MAC filtered". If you are talking about blocking it with the Wireless MAC Filter then the device won't be able to connect at all. So it won't get as far as being able to request an IP address from DHCP.

Are you using any WiFi repeaters or range extenders?

You could try changing your SSIDs and/or passwords and then update your clients one at a time until you find the rogue device. Alternately, turn off all of your WiFi devices and then turn them back on one at a time.

Of course it might not be a WiFi device at all in which case you need to examine your wired devices. Do you have any PCs running VMs?

 

[xMaN73]

I'm not sure what you mean by "have it MAC filtered". If you are talking about blocking it with the Wireless MAC Filter then the device won't be able to connect at all. So it won't get as far as being able to request an IP address from DHCP.

Are you using any WiFi repeaters or range extenders?

You could try changing your SSIDs and/or passwords and then update your clients one at a time until you find the rogue device. Alternately, turn off all of your WiFi devices and then turn them back on one at a time.

Of course it might not be a WiFi device at all in which case you need to examine your wired devices. Do you have any PCs running VMs?

Yes, I am using the wireless MAC filter to Allow only devices in my MAC table.

I don't have any repeaters or extenders.

I think I figured out what is happening. I rebooted my ASUS RT-AC68U and the DHCP server stopped trying to assign an IP to the 00:45:b9:26:54:8d. BUT, now it's trying to assign IP address to 3 other devices that already have IPs assigned to it already. It has something to do with the DHCP server keeping the lease on the MACs. I have the lease time set to 86400 sec. Is there a way to force a clear on the DHCP table?

 

[ColinTaylor]

BUT, now it's trying to assign IP address to 3 other devices that already have IPs assigned to it already. It has something to do with the DHCP server keeping the lease on the MACs. I have the lease time set to 86400 sec. Is there a way to force a clear on the DHCP table?

Rebooting the router should clear any lease information the router has. You can see them at System Log - DHCP leases.

You should power off the troublesome devices, reboot the router, and when the router is fully up turn the devices back on.

 

[xMaN73]

Rebooting the router should clear any lease information the router has. You can see them at System Log - DHCP leases.

You should power off the troublesome devices, reboot the router, and when the router is fully up turn the devices back on.

Yeah, I think just rebooting the router works sometimes on clearing the DHCP lease. If I left it off for a while, it would probably clear it. Rebooting the devices does help it. It's just harder when your IOT device is a light switch that's causing the issue.

Thanks for the help!