DHCP log full of wan renewal requests

applesalwaysred

Hi, noticed my dhcp log is full of dhcp requests for wan renewal. Message of 'DHCPREQUEST on mvneta0...'.
When I force refresh wan dhcp, log is empty for number of hours until, I assume, lease renewal time. Using kea dhcp, 24.11 release.
What steps to review this?
Thanks

stephenw10

If it's on the WAN that should be from the dhclient process like:

 Dec 16 11:31:55 	dhclient 	7311 	DHCPREQUEST on mvneta0.4090 to 192.168.126.1 port 67
Dec 16 11:31:55 	dhclient 	7311 	DHCPACK from 192.168.126.1
Dec 16 11:31:55 	dhclient 	87209 	RENEW
Dec 16 11:31:55 	dhclient 	88106 	Creating resolv.conf
Dec 16 11:31:55 	dhclient 	7311 	bound to 192.168.126.10 -- renewal in 3600 seconds.

You should only see those each time it renews.

That's independent of the DHCP server on internal interfaces.

Steve

applesalwaysred

@stephenw10 I see the dhcpack response Dec 15 at 04:36:36 and the rest of what you mentioned. The renewal is ~17 hours (61825 seconds).
Then Dec 15 21:47:01, the renew requests start again, after 16 hours of the last renewal.
The dhcprequests continue until wan is manually refreshed.
wan dhcp question.png

stephenw10

And they just continue until eventually the server responds with dhcpack?

The dhclient will start to try to renew at half the lease time. It looks like the server is just ignoring it though. That's the upstream dhcp server at the ISP?

applesalwaysred

@stephenw10 Yes, upstream dhcp server at the isp. Is this then an issue on the isp, why they don't supply a renewal in a timely manner?

stephenw10

Good question. It's harmless log spam as long as they do respond before the lease ends.

You could try some custom dhcp options to reduce it if you need to.

applesalwaysred

@stephenw10 Please advise those custom options as it is renewing the log file due to cycling.

stephenw10

Enable dhcp advanced options. Then you can add custom send options like:
dhcp-lease-time xxx
Or override the lease time passed in the option modifiers like:
supersede dhcp-lease-time xxx

The server may or may not just ignore what ever lease time you request in the send options.

johnpoz

You have some disconnect between your renewal time and when the server thinks it should give you a renewal? Multiple leases in your lease file?

What should happen is say you get a 2 hour lease, approx 1 hour later your client should renew and the server should answer, then another hour later it would renew again.

If the sever is not answering then yes the client will start going crazy asking more and more often until it either gets the renewal - or it finally times out at which time it would then send out a discover.

Normally the server will not answer if the request for renewal is too early into the lease.

My isp hands me a really long lease, 7 days you can see here

Where the renew time is 3.5 days and from the lease file on pfsense

Might want to look in your dhclient.leases.interface in /var/db and clean up any old leases.. Could release your IP, then go into that file and clear it out..

applesalwaysred

@stephenw10 @johnpoz thanks!