Date: Sun, 9 Dec 2001 11:57:59 -0500 From: "Oliver, Michael W." <oliver.michael@gargantuan.com> To: "'jacks@sage-american.com'" <jacks@sage-american.com> Cc: "'freebsd-questions@freebsd.org'" <freebsd-questions@freebsd.org> Subject: RE: Scripting help Message-ID: <1DA741CA6767A144BAA4F10012536C27A923@LKLDDC01.GARGANTUAN.COM>
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Jack,
I just tried this on my server, and had to make a couple of tweaks.... This
might be better....
#!/bin/sh
while [ 1 ]
do
LAST_KNOWN_IP=`cat last_known_ip_file`;
CURRENT_IP=`ifconfig sis0 | grep inet | grep -v inet6 | awk ' { print
$2; } '`;
if [ -z "$LAST_KNOWN_IP" ]
then
# run your dns ping program here using $CURRENT_IP
echo $CURRENT_IP >last_known_ip_file;
continue
fi
if [ "$LAST_KNOWN_IP" = "$CURRENT_IP" ]
then
sleep 30;
continue
else
# run your dns ping program here using $CURRENT_IP
echo $CURRENT_IP >last_known_ip_file;
fi
done
EOF
Of course, you would have to change the 'sis0' interface name to the one you
are looking to monitor. HTH....
===========
Michael Oliver
> -----Original Message-----
> From: jacks@sage-american.com [mailto:jacks@sage-american.com]
> Sent: Sunday, December 09, 2001 11:51 AM
> To: Oliver, Michael W.; freebsd-questions@freebsd.org
> Cc: Oliver, Michael W.
> Subject: RE: Scripting help
>
>
> Thanks Michael, will work on it....
>
> At 11:32 AM 12.9.2001 -0500, Oliver, Michael W. wrote:
> >Jack,
> >
> >Well, this will be my first script written from scratch, so
> please be kind
> >if I dork it up! Try this:
> >
> >
> >
> >
> >
> >
> >#!/bin/sh
> >
> >while [ 1 ]
> >do
> >
> > LAST_KNOWN_IP=`cat last_known_ip_file`
> > CURRENT_IP=`ifconfig tun0 | grep inet | awk ' { print $2; } '`
> >
> > if [ -z "$LAST_KNOWN_IP"]
> > then
> > # run your dns ping program here using $CURRENT_IP
> > echo $CURRENT_IP >last_known_ip_file
> > continue
> > fi
> >
> > if [ "$LAST_KNOWN_IP" = "$CURRENT_IP" ]
> > then
> > sleep 30
> > continue
> > else
> > # run your dns ping program here using $CURRENT_IP
> > echo $CURRENT_IP >last_known_ip_file
> > fi
> >
> >done
> >
> >EOF
> >
> >
> >
> >
> >
> >
> >
> >
> >Please let me know how it turns out ;-)
> >
> >===========
> >Michael Oliver
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >> -----Original Message-----
> >> From: jacks@sage-american.com [mailto:jacks@sage-american.com]
> >> Sent: Sunday, December 09, 2001 11:02 AM
> >> To: freebsd-questions@freebsd.org
> >> Subject: Scripting help
> >>
> >>
> >> I have just set up an experimental FBSD 4.4-STABLE server
> >> using DSL with
> >> dynamic ip. Using ZoneEdit DNS services, the DNS can be
> >> updated with a cron
> >> script to still point to the proper name. I'm doing that now
> >> using cron to
> >> run the update script every 8 hours (the connection usually
> >> runs for weeks
> >> at a time without disconnect).
> >>
> >> However, I had rather have a script that runs every so often
> >> (xminutes) and
> >> doesn't bother the DNS server unless and ONLY if a changed in
> >> the dynamic
> >> IP has occured as a result of disconnect/reconnect. Here are
> >> the functions
> >> I see needed, but scripting language is not yet a decent
> >> skill of mine. I
> >> suspect others using dynamic IPs have this same need: Any guidence
> >> appreciated once again. (I've looked at the ipcheck that uses
> >> Python, but
> >> rather not go that route if possible to do the simple
> >> approach below).
> >>
> >> BEGIN (my crude) SCRIPT:
> >> #!/bin/sh
> >> PATH=/usr/local/bin:/usr/bin:/bin
> >> ## This script would be run by cron every x_minutes
> >> ## (files needed: "last_known_ip" and "my_current_ip")
> >> ## Contents of last_known_ip (placed there manually at for
> >> first output
> >> ## by running ifconfig tun0 > last_known_ip
> >>
> >> tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1492
> >> inet 64.xxx.xx.20 --> 64.xxx.xx.254 netmask 0xffffffff
> >> Opened by PID 149
> >>
> >> ## Run update to my_current_ip file
> >> # function: ifconfig tun0 > my_current_ip
> >>
> >> ##.... so the "my_current_ip" file would contain output of:
> >> tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1492
> >> inet 64.xxx.xx.20 --> 64.xxx.xx.254 netmask 0xffffffff
> >> Opened by PID 149
> >>
> >> ## Now make comparison to see if dynamic ip has changed and
> >> update DNS if
> >> changed.
> >> # function: look in my_current_ip and find the current ip
> >> (64.xxx.xx.20)
> >> # function: look in last_known_ip file and find ip (64.xxx.xx.66)
> >> # function: if not same, then run DNS_ping_program to update
> >> (ping command
> >> here)
> >> ## If change detected, update comparison file
> >> # function: ifconfig tun0 > last_known_ip
> >> # function: if same ip, then do nothing
> >> END OF SCRIPT
> >>
> >> The above may be a crude approach, but best way I can define
> >> the job for
> >> now....
> >>
> >> Best regards,
> >> Jack L. Stone,
> >> Server Admin
> >>
> >> Sage-American
> >> http://www.sage-american.com
> >> jacks@sage-american.com
> >>
> >> To Unsubscribe: send mail to majordomo@FreeBSD.org
> >> with "unsubscribe freebsd-questions" in the body of the message
> >>
> >
> >
>
> Best regards,
> Jack L. Stone,
> Server Admin
>
> Sage-American
> http://www.sage-american.com
> jacks@sage-american.com
>
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