Re: Amcheck and amdump port usage?

Sorry for the long delay in response, I've been busy....

--On Monday, September 13, 2004 16:54 -0400 KEVIN ZEMBOWER<KZEMBOWE AT jhuccp DOT org> wrote:

Michael, thank you for taking the time to try to help me. Please see my
further questions below.

Michael Loftis <mloftis AT wgops DOT com> 09/13/04 03:04PM >>>


--On Monday, September 13, 2004 14:24 -0400 KEVIN ZEMBOWER
<KZEMBOWE AT jhuccp DOT org> wrote:

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.

Your steps are pretty wrong so lets start over......

1. tapehost makes 'start backup, estimate/etc' call to amandad over UDP
on  remote (usually 10080) client sends back response(s) to udp port
(udpportrange).


The UDP packet is sent from the tapehost from which port? Is it correct
that it always goes to port 10080 on the client, no matter what is
defined in the compilation of amanda with --with-portrange
--with-udpportrange or --with-tcpportrange?

From an ephemeral port, IE it varies depending on your OS. And it always

goes to the 'amanda' service, which is usually defined as 10080/udp. Andyes the compile time options do not control the source port for these.

Which port on the client does the response come from?

Same, ephemeral, but it goes TO one of the UDP Ports specified byudpportrange parameter. Later TCP data connections may be attempted on thetcpportrange, as well as the amandaidx and amidxtape services (for restoresthough)

2. after response/receipt of estimates (Assuming backup run) at some
point  later the server sends start backup, this packet contains a tcp
port to  connect to on the server in the tcpportrange/portrange (these
are the  same).  the client may also connect to amandaidx on the tape
server as well  to transmit indices at this time (I can't remember, and
it does depend on  the index option in the dumptype config).  Once
connected the client begins  transmitting backup data to the server.


Is it correct that the packet of 'start backup' from the tapehost is sent
UDP?  From which port on tapehost? What port on the client is it
addressed to? Is it the same ports on both tapehost and client as the
ports in step 1?

Yes correct, sent UDP from an ephemeral port to 10080/udp on the client.All operations are basically two-step, a request going out from the tapeserver to amanda (usually 10080/udp) on the client, which responds back toa port selected by the server (one inside of --with-udpportrange) when itcompletes the operation.

Is the amandaidx port on the tapehost always 10082/tcp, regardless of the
--with-???portrange switches?

Yes, all of the services are, I've gone ahead and pasted the entries below,your installation won't use the kamanda ports.


amanda          10080/udp                       # amanda backup services

kamanda 10081/tcp # amanda backup services(Kerberos)kamanda 10081/udp # amanda backup services(Kerberos)

amandaidx       10082/tcp                       # amanda backup services
amidxtape       10083/tcp                       # amanda backup services


Sorry it took so long to get back to you.