DSL and NAT'ed customer addresses

[Joshua Bergland]

I am using ddclient as my dyndns client, and it has an option in its 
configuration file to have it use 'web based IP detection' ... it 
checked the information returned by http://checkip.dyndns.org and then 
uses that to set the ip address for your chosen domain :-)

Make sure to set it to only change your dyndns settings at the dyndns 
only if your ip address changes, as doing it more frequently is 
considered abuse according to dyndns.org

http://clients.dyndns.org/unix.php?service=dyndns

Just my two cents,
Josh

Hanasaki JiJi wrote:

> NAT
>
> MyLinuxBox(ip=ip1) <== NATer ==> outside world (ip=ip2)
>
> dyndns does a great job for dynamically assigned/changing IPs but how 
> does it help when the insideIP!=outsideIP?
>
> Jason Clinton wrote:
>
>> Hanasaki JiJi wrote:
>>
>>> Any thoughts on how he might run a server that can have connections 
>>> initiated to it from anywhere on the net?
>>>
>>
>> If he's behind a NAT he needs two things:
>>
>> 1. The ability to update the IP address of the router to a dyndns 
>> service like dyndns.org so that no matter what his IP address is at 
>> any given time, you can still find it from outside his NAT.
>>
>> 2. The NAT needs to be able to 'port forward' the port the particular 
>> server would run on. IE: port 80 for HTTP, 21 FTP, 22 SSH, 23 Telnet, 
>> 25 SMTP.
>>
>> If you have the ability to let people know you're running on some odd 
>> ports then you'll be better capable of avoiding your ISP's probes for 
>> users running service (which is a violation of most end user 
>> agreements). In the case of SMTP, you don't have a choice because all 
>> SMTP servers look at port 25. In the case of HTTP, however, you could 
>> distribute a URL that contains the port number it in like this:
>>
>> http://archemides.homeunix.org:8888/
>> (i don't actually have an http server running here)
>>
>