Is this a good firewall?

[Pedro Fernandes Macedo]

Kevin Old wrote:

>Here are a few questions:
>
>1) Is there I can allow a dynamic hostname to have unlimited access to
>the server?  For example, if I'm a Comcast subscriber the hostname to
>my cable modem is 12-134345-112.nashville.comcast.com or something
>like that.  Is there a way I can create a firewall rule to allow all
>*.nashville.comcast.com requests for any port rather than a static IP?
>  
>
I wouldnt enable a wide range like that... What I would do is a little 
shell script magic to open just the necessary IP...
This is how I'd do it:
1 - Register a dynamic DNS entry in any service like dnsalias.org . get 
the autoupdate client and configure it on the machine connected to comcast.
This way , every time your home IP changes , the dns entry will be 
pointing to it.
2 - make a little shell script which does something like this and set it 
to run every 5 minutes on cron:
     get the ip for hostname myhomemachine.dnsalias.org (for example)
     if $HOMEIP is set , compare it with the IP you got on the first 
step . If they are the same , just exit. If they're different:
     set the $HOMEIP var and run the bash script of the firewall

This should be enough , if the firewall script uses the $HOMEIP variable 
to configure the necessary lines..


>2) Are there other restrictions I should place on the 9 ports I have
>open?  If so, what are they?
>  
>
Sorry. Couldnt open your firewall script here.. my provider sometimes 
has issues with some random servers :|

--
Pedro Macedo