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Re: Firewall with dynamic IP

Which DHCP client are you running? If you use dhcpcd, it will run a script
(/etc/dhcpc/dhcpd-eth*.exe, replacing * with the appropriate interface
number) when it gets a lease change. Use that mechanism to notify yourself
of the lease change somehow.

What "somehow" to use depends on what you have available. 

If you have a facility for sending *outgoing* mail available (mail doesn't
have to be "running", in an inetd-like sense, to do this), a short perl or
shell script will send a copy of the lease file (/etc/dhcpc/dhcpd-eth*.info,
I believe) to wherver you want it to go.

If you have ssh running, do you have scp as well? You could scp the lease
file to someplace useful.

There are several services that provide dynamic DNS. I've never looked at
how they get their information about lease updates, but they must have
developed some method(s). You might see what they do and if you can adapt it
to your requirements.

At 05:30 PM 8/11/00 +0200, Julien Stern wrote:
>I have a stupid problem with my firewall.
>It's very simple (no DMZ) and it has a dynamic IP.
>Everything works fine. However, I would like to be
>able to know what's the new IP of my firewall when I'm
>Nothing runs of the firewall except ssh2 and syslogd
>(oh, well there is cron, portmap, tcplogd and a few others, but
>no ftp, telnet, web, rlogin, mail... no services basically).
>So, how to get the firewall new IP when it changes?

------------------------------------"Never tell me the odds!"---
Ray Olszewski                                        -- Han Solo
Palo Alto, CA           	 	         ray@comarre.com        

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