Merlin Firmware 380.57: Log Message Every 10 Minutes

[salieri]

Merlin Firmware = 380.57
Router = AC68U

I keep getting this message several times in my system log every 10 minutes and would like to understand why:

Dec 30 13:11:25 dnsmasq-dhcp[452]: DHCPDISCOVER(br0) <snip mac address>
Dec 30 13:11:25 dnsmasq-dhcp[452]: DHCPOFFER(br0) 192.168.2.7 <snip mac address>

Please advise, thanks...

 

[Nullity]

That is someone on your network being offered an IP and them accepting the offer.

DHCP is one the the most ubiquitous computer networking protocols. Your log seems absolutely normal to me.

You are using 192.168.2.* (192.168.2.0/24) as your DHCP pool?

 

[salieri]

Correct, that's my DHCP pool.

Guess that's a new system logged item for me and threw me off. I recently upgraded from Asus's stock firmware version 3.0.0.4.380.1031 and hadn't seen those messages until I upgraded to the merlin version.

 

[Nullity]

Actually, I think I got it wrong with my first post.

The discovery is the client requesting a DHCP server.
The offer is the DHCP server telling the client what is available.

Every 10min is not too often, but if it is 24/7, I might be concerned.

 

[Ronv42]

iPad's, Wii's, Playstations and Xbox's all seem to get into the multiple requests process when they are sleeping, waking up, using low power mode etc. Having a nosiy system log for DHCP is normal. Heck a laptop in connected standby will connect every 5 minutes depending on the needs of the operating system.

I blame a lot of this on the devices that connect that aren't well programmed. There is this one email app that follows Apple's power saving to the exstream that was causing the wifi on a phone to connect every minute and Apple's power management on their phones is super agressive to turn off and on.

 

[bits]

Do you happen to have a CCTV system in the network.

My swann brand system does dhcp request constantly.

 

[darkstalker]

Go to the LAN-DHCP server configuration and change the following setting to Yes:
Hide DHCP/RA queries

Profit

 

[eddiez]

Go to the LAN-DHCP server configuration and change the following setting to Yes:
Hide DHCP/RA queries

Profit

This will not prevent the calls. It will just not show them

I have them too, my UPC mediabox is generating a call like this every minute. Not even a reboot of the mediabox makes it go away.

 

[tomislav]

It's normal. My Wi-Fi iPad Air 2 does it every 10 minutes... Xbox One will also connect often. Basically anything with just Wifi that's sleeping.

Ideally, if the DHCP lease time is set to 24h, they should do a request after 12h. But hey... unless you have a few hundred devices connected it doesn't matter much.

 

[sfx2000]

Something is wrong if one is getting multiple DHCP Discover messages from the same client...

See the finite state machine below...

 

[salieri]

Do you happen to have a CCTV system in the network.

My swann brand system does dhcp request constantly.

I do have a Foscam and notice a lot of the messages are triggered from that device as well as Apple products it seem

iPad's, Wii's, Playstations and Xbox's all seem to get into the multiple requests process when they are sleeping, waking up, using low power mode etc. Having a nosiy system log for DHCP is normal. Heck a laptop in connected standby will connect every 5 minutes depending on the needs of the operating system.

I blame a lot of this on the devices that connect that aren't well programmed. There is this one email app that follows Apple's power saving to the exstream that was causing the wifi on a phone to connect every minute and Apple's power management on their phones is super agressive to turn off and on.

Yep noticed the other set of queries comes a lot from Apple devices.

Go to the LAN-DHCP server configuration and change the following setting to Yes:
Hide DHCP/RA queries

Profit

Good to know, thank you.

---

Appreciate the replies and explanations. Another new thing I've learned...