Dynamic DNS (DDNS)

J. Seth Henry jshamlet at comcast.net
Wed Jun 11 09:04:04 PDT 2003

I'm on Comcast in MD, and my DHCP lease is a bit longer - on the order of 3 
months. Not sure if that is because I am a holdover of @Home or what. Just a 
note of caution, though. Comcast doesn't technically allow any kind of 
server. They will tolerate SMALL servers that don't generate a lot of 
bandwidth "under the radar" though. I have a *very* private FTP server, sshd 
and telnet (to my UPS). The rest is firewalled off. As unfair as it may seem, 
getting busted for running an FTP/HTTP server is worse than for running Kazaa 
or some other P2P crap. (despite the fact the latter tend to use more 

I get around the dhcp problem by having my system send me an email every 
morning - and looking at the headers. It's also a great way to get morning 
status from my systems.

I thought about going to the DDNS route, until I heard stories of Comcast 
dropping customers who did this. There is also the fact that Comcast, unlike 
Millenium, doesn't actually block any ports (yet). (I think 25 may be an 
exception). I fear if very many people start trying to run servers and attach 
them to DNS records, Comcast may start blocking inbound ports as well.

Yes, this warning is self-serving. If Comcast starts blocking ports, the only 
choice left is DSL - and I HATE verizon with a passion. They have screwed me 
over so many times, I lost count; and I dread the day I have to sign up for 
DSL because Comcast actually starts enforcing the "no server" rule strictly.

Seth Henry

Hello. I am on Comcast CABLE and the DHCP lease is
only 4 days to expire, all the time. So my IP changes
every four days. I was wondering in FreeBSD
(FreeBSD4.8) how I can set up Dynamic DNS. I checked
the online docs and I could not find anything on DDNS,
is it some rc.x file or a file in /etc for me to edit?
I would be more than happy if you got back with me
A.S.A.P. Thanks.

- Jay Buhrt

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