I'm still trying to troubleshoot my problem getting Amanda to work though
a firewall. I've read John Jackson's  port usage document and the FAQ at
http://amanda.sourceforge.net/fom-serve/cache/139.html. I'd like someone
to comment on whether or not I have the overall communication sequence
correct below. Then, I'd like information on how this is different if
amcheck rather than amdump is run.

In compiling amanda, I used these options: "--with-portrange=10080,10083
--with-tcpportrange=10080,10083 --with-udpportrange=850,854".

This is what I understand concerning the sequence of port usage in making
an amanda backup:

1. The tapehost makes a 'start backup' request of the client, originating
on port 850-854 to port 10080-10083 using UDP. The contents of the packet
contain a port number in the range 850-854 which is open on the tapehost,
listening for TCP connections.

2. The client responds by sending a UDP packet from any (?) port to port
850-854 on the tapehost. [Q: Can ports 850-854 on the tapehost be open to
receive both UDP and TCP packets at the same time?] The contents of the
packet are port numbers in the range 10080-10083 on the client which are
listening for TCP packets from the tapehost.

3. The tapehost responds by sending a packet from port 10080-10083 using
TCP to port 10080-10083 on the client. This packet starts the
transmission of the backup data from the client to the tapehost, using
the same port numbers just used.

Thanks for reviewing this and letting me know whether I've got it right.
I appreciate your patience and help.

-Kevin Zembower


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E. Kevin Zembower
Internet Systems Group manager
Johns Hopkins University
Bloomberg School of Public Health
Center for Communications Programs
111 Market Place, Suite 310
Baltimore, MD  21202
410-659-6139

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