Remote admin of computer inside a firewall

[diarmuidw]

Hi Guys,
I have Linux computers that are often on client networks inside firewalls . They have access to the internet but I can't access them directly. I don't want to have to get the client to mess with NATing , etc . I have written a system that uses XMPP to allow me to send commands to the computers and run simple console commands which often time is enough. These are things like run a report and ftp up to server, restart a process, give me a process list. It works OK, but some networks even block this (Googletalk is not universally loved for some reason)

I am wondering if there is a prebuilt system that allows me a computer inside one firewall (say a standard adsl modem created one) communicate in some way with a computer inside a network created by another adsl modem. I could see some sort of console like logmein or pc anywhere but as much as I have looked I can't find anything. I have considered writing a cheap and cheerful system in http or even a TCP system using asyncore in python but there must be something existent. I have a server on the web that could be used as an intermediary, relay type thing. Basically some sort of chat server for consoles is what I am thinking about.

Is there some sort of SSH voodoo that I could bridge/tunnel/vpn through.

Any Ideas?

Thanks

Diarmuid

[diarmuidw]

BTW, This isn't me trying to write a trojan or any other rubbish in case it comes across that way

[diarmuidw]

I suppose I could use twitter, because Real Time control is not absolutely required. Not withstanding their stability issues, their clients and all that funding has to be reassuring.

Or one of the clones like laconi.ca or StatusNet (bothe php) or Jaiku (in python so better for me)

Diarmuid

[jledhead]

you could use something like hamachi https://secure.logmein.com/products/hamachi2/
not free but something you can use without messing with client firewalls. unfortunately logmein doesn't work on linux (as far as I know)
also not free
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for free, the best solution would probably be to get an open port and use ssh, but probably not on the default port.