i think i almost have the default pass, i have to understand one more function

verb/fs.sbin/config-dns.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+#
+# $Id: config-dns.sh,v 1.2 2007-10-15 08:26:00 winfred Exp $
+#
+# usage: config-dns.sh [<dns1>] [<dns2>]
+#
+
+fname="/etc/resolv.conf"
+fbak="/etc/resolv_conf.bak"
+
+# in case no previous file
+touch $fname
+
+# backup file without nameserver part
+sed -e '/nameserver/d' $fname > $fbak
+
+# set primary and seconday DNS
+if [ "$1" != "" ]; then
+  echo "nameserver $1" > $fname
+else # empty dns
+  rm -f $fname
+fi
+if [ "$2" != "" ]; then
+  echo "nameserver $2" >> $fname
+fi
+
+cat $fbak >> $fname
+rm -f $fbak
+