"Creating resolv.conf" every minutes

wxop

I'm using a WAN, LAN, and WLAN ports, Captive Portal on the WLAN and DHCP servers on the LAN and WLAN.

Here is what i get in /var/log/system.log:


Dec 17 10:31:18 gate dhclient: Creating resolv.conf
Dec 17 10:32:18 gate dhclient: RENEW
Dec 17 10:32:18 gate dhclient: Creating resolv.conf
Dec 17 10:33:18 gate dhclient: RENEW
Dec 17 10:33:18 gate dhclient: Creating resolv.conf
Dec 17 10:34:18 gate dhclient: RENEW
Dec 17 10:34:18 gate dhclient: Creating resolv.conf
Dec 17 10:35:18 gate dhclient: RENEW
Dec 17 10:35:18 gate dhclient: Creating resolv.conf
Dec 17 10:36:18 gate dhclient: RENEW
Dec 17 10:36:18 gate dhclient: Creating resolv.conf
Dec 17 10:37:18 gate dhclient: RENEW
Dec 17 10:37:18 gate dhclient: Creating resolv.conf
Dec 17 10:38:18 gate dhclient: RENEW
Dec 17 10:38:18 gate dhclient: Creating resolv.conf
Dec 17 10:39:18 gate dhclient: RENEW
Dec 17 10:39:18 gate dhclient: Creating resolv.conf

I've observed this behaviour on all screenshots i've upgraded to during the last two Months.
Current version: 2.0-BETA4 Built On: Thu Dec 16 14:34:04 EST 2010

More Infos:


# ls -l /etc/resolv.conf
lrwxr-xr-x  1 root  wheel  20 Dec 15 08:28 /etc/resolv.conf -> /var/etc/resolv.conf
#ls -l /var/etc/resolv.conf
-rw-r--r--  1 root  wheel  56 Dec 17 10:27 /var/etc/resolv.conf
#more var/etc/resolv.conf
 domain lo.lo
 nameserver 10.1.10.1
 nameserver 10.1.10.11

Is this normal? If not, Where should I investigate?

jimp

Looks like your upstream DHCP provider has a one-minute lease timeout. Your DHCP client is renewing every minute, and when it does, it rewrites the DNS servers based on the DHCP reply.

Such a ridiculously short lease time is bound to cause other issues… If your ISP is open to fixing that, it has to be fixed on their side.

wxop

Jimp, Thank you for the reply

Yes my ISP DHCP server may renew its Lease every minutes. I could bypass this by assignign the static IP given by my ISP instead of using DHCP on WAN: In my current configuration, it would not be the most convenient.

But Is it normal that pfSense rewrite the resolv.conf file every time, despite I tell him NOT to use my ISP DNS servers.
(Systeme/General Setup/"Allow DNS server list to be overridden by DHCP/PPP on WAN" is NOT ticked)?

Theses line in resolv.conf:
domain lo.lo
nameserver 10.1.10.1
nameserver 10.1.10.11

are my own internal DNS servers…Absolutely not related to the ISP.

jimp

Not sure what the logic for updating DHCP received DNS servers looks like (I haven't looked at the code for that in 2.0 in quite a while), but if you have the allow override boxed unchecked it should probably not be updating that file.