How can I silence WAN dhcp logging messages

Installing and Using OpenWrt Network and Wireless Configuration
1

My WAN connection is setup to use dhcp. The ISP issues IP addresses with a lease time of 10min . No idea why. I'm curious why, using both ipv4 and 6 means every 5 min the router starts asking for a new address. If this is none by every customer they have, it must create quite a bit of traffic.
The syslog file keep filling with renew messages. Is there a way to silence these logging messages. Lots of parameters for logging on LAN side for local DHCP server but cannot find any option parameters for the WAN client side.

2

RFC 2131
When a DHCP client starts and 50% or 87.5% of its IP address lease has passed, the DHCP client sends a DHCP Request message to the DHCP server to renew the lease.

3

You're right... but that's on their side -- customers cannot control it. They must have a reason... or maybe they don't realize that it's stilly to have such short leases for a whole bunch of reasons.

I might be wrong, but AFAIK, you would need to build your own firmware from source to be able to disable this logging... there should be some switches in the udhcpc related code to enable/disable logging, but I don't believe that it is accessible post-compile.

1 Like
4

This question has already been asked and there is no satisfactory answer.
If this is so annoying for you, replace logd with syslog-ng and set a filter.

#/etc/syslog-ng.conf
...

destination messages {
        file("/var/log/messages");
};

# udhcpc renew filter start

filter drop_dhcp_renew {
match ("sending renew") or match ("lease of")
};
log { source(src); filter(drop_dhcp_renew); flags(final); };

# udhcpc renew filter end

log {
        source(src);
...
1 Like
5

What is your ISP?
I had once one in France which indeed sets a DHCP lease to 10 min.

6

Highland Broadband in UK

1 Like
7

Looking at the Status->Overview page, the data in the network port for ipv4 and ipv 6 show different expiry times, each have a 10 min interval, but they are not running in sync with each other