Firewall file transfer problem

[nachobel]

Hey guys

Alright, so here's my problem. I am at school and am protected by a firewall. A friend of mine is at another school and is also protected by a firewall. I was trying to send him a file over AIM's file transfer service, but it wouldn't connect. So I tried to FTP to his machine (we are both running OS X) and it coouldn't find his IP. This is because of the firewall. How can we get around the both of them so that we can transfer files? Is this possible?

nachobel

[xchanyazy]

Don't know what's blocked between the two of you, but have you tried afp://hisip, or starting web sharing and having him use his browser to download from you?

[ld50]

both of you wouldn't by any chance be behind a NAT'ed firewall?

its common for LANs to use NAT (Network Address Translation) in these days of diminishing IP addresses. If this is the case it would explain why you couldn't find their IP address, because it would ba a private address and no route to it on the internet.

mh

[Novajo]

If either of you is behind a firewall (but not both), you should be able to issue a passive request command to the ftp server. Assume you are behind a firewall, he is not. Then you should use the PASSIVE mode when you transfer files. If he is behind a firewall, you should be in ACTIVE mode. Fetch, and others have an option for PASSIVE mode. Interarchy has one to, but it does not work: it's always active. The command line tool "ftp" goes to passive mode when you type PASV. If you are both behind a firewall, then that will not work.

The other option is to use secure ftp. You can use sftp from the terminal or get a limited copy of MacSFTP (http://www.versiontracker.com/moreinfo.fcgi?id=12685&db=mac) on versiontracker.com. To use secure ftp, you must have an account on the machine and it must be running ssh. This works flawlessly through firewalls.