ip refresh, resolv.conf and local scripts on startup?

[RW]

On Tue, 8 May 2007 16:11:21 -0500
"Jack Barnett" <jackbarnett at gmail.com> wrote:

> I have a script that updates some dynamic DNS records (can be run as
> non-root if needed).
> 
> It needs to be run on startup - after network is configured and after
> rc.firewall (it'll get blocked if it's run before the firewall is
> setup).
> 
> What is a good place to put this?  I could put it at the end of
> rc.firewall, but is there a better place to put it?

This is a problem that people see when they need to update a local
dhcp server on a machine that gets its own settings by dhcp. Try google.


> Also how do I refresh a dynamic IP without rebooting?
> 
> Sometimes my cable modem gets messed up and under windows I just do:
> ipconfig /release
> ipconfig /renew
> 
> and it gets new IP and sets everything up.  In FreeBSD is there a way
> to reconfigure everything without rebooting?

/etc/rc.d/dhclient restart

should do it

> (rc.firewall uses this to get network info:
>         onet=`ifconfig xl0 | grep "inet " | awk '{print $6}'`
>         oip=`ifconfig xl0 | grep "inet " | awk '{print $2}'`
> Meaning, rc.firewall would also have to be re-ran if the IP is new).
> [also to make things more complicated, I think I need a rule in
> rc.firewallto allow for DHCP clients to go out?  It gets blocked on
> external interface
> when firewall comes up??]

I doesn't appear to matter, I think dhclient bypasses the firewall. at
least that's my experience with PF.

> Also how do I override /etc/resolv.conf?  DHCP client configures it I
> think and sets it up to point to my ISP DNS servers (which suck) and
> would like to give it mine instead of there, but it keeps getting
> over written on startup when it gets a DHCP lease?

See dhclient.conf(5) for how to control what DHCP does to resolv.conf,