My purpose here is to allow dynamic dns updates via nsupdate from a dhcp clients where addresses are subject to change. I have a solution that will remain stable so long as the !command hook in hostname.if remains stable. This is not as good as the dhclient.conf script interface as it can't exclude calls that don't change the interface, but hey...
# more /etc/hostname.nfe0 dhcp !/usr/local/sbin/dydns.sh $if more /usr/local/sbin/dydns.sh #!/bin/ksh #rdate to make sure we're sync'd with the dydns server echo $@ >> /tmp/ddns.log date >> /tmp/ddns.log /usr/sbin/rdate -o 192.168.1.22 export ADDR=`ifconfig $1 | grep "inet "| cut -d ' ' -f 2` echo "server 192.168.1.22 zone indx.ca key u32.indx.ca 7U6+9Bqymcyn21vLHIlf9DWVIYvljkn/GIMqNhg3YpaSxUDoarpBPz/J Pm52kWD9GG1mpewiiKsYCcarWF2wUg== update delete u32.indx.ca. A update add u32.indx.ca. 86400 A $ADDR send " | nsupdate exit 0 where key is the shared private key produced by the output of dnssec-keygen -a HMAC-MD5 -b 512 -n USER u32.indx.ca. found in the output file Ku32.indx.ca.+157+08659.private and added to /var/named/keys.conf on the named server in the form key "u32.indx.ca" { algorithm hmac-md5; secret "7U6+9Bqymcyn21vLHIlf9DWVIYvljkn/GIMqNhg3YpaSxUDoarpBPz/J Pm52kWD9GG1mpewiiKsYCcarWF2wUg=="; }; and an entry to etc/named.conf zone "indx.ca" { ... allow-update { . . key u32.indx.ca ; . . }; }; Dhu On Mon, 29 Sep 2014 14:13:48 +0200 Bruno Flueckiger <inform...@gmx.net> wrote: > On 29.09.2014 13:39, Duncan Patton a Campbell wrote: > > On Mon, 29 Sep 2014 05:28:27 -0600 > > Duncan Patton a Campbell <campb...@neotext.ca> wrote: > > > >> /etc/dhclient.conf used to contain a > >> > >> script "tosomfile" ; > >> > >> option that could, amongst other things, be used to > >> set a dynamic assigned dns address to a named server. > >> > >> This functionality has been removed and I am trying to > >> figure out if there was some other mechanism to accomplish > >> this but I can't find any refs to it in the changes > >> between 5.1 and 5.5. > >> > >> Any info would be appreciated. > >> > >> Thanks, > >> > >> Dhu > >> > >> -- > >> Ne obliviscaris, vix ea nostra voco. > >> > >> > >> > > > > I found it in the 5.3 changes.. > > > > "Removed dhclient-script(8) and dhclient.conf(5) "script" directive. > > Do all interface and route configuration via ioctl's and routing > > sockets. " > > > > Unfortunately this mechanism was used for more than just routing. And > > without a dhclient-script to > > hack I don't see how a dynamic address can be updated vi the named/key > > mechanism. > > > > Dhu > > If your goal is to set entries in DNS for a machine which acts as DHCP > client there are two other possibilities I know of: > > 1. Use a reservation in DHCP server together with fixed entries in DNS > > 2. Get ISC DHCP from ports and configure it to make dynamic updates to > BIND > > Depending on your exact setup there may be other ways to achieve the > same as you did with the script. > > Bruno > > -- Ne obliviscaris, vix ea nostra voco.