Problem: nntp-open-via-rlogin-and-telnet (how to debug?)

[Gernot Hassenpflug]

I am using No Gnus v0.4 with x86 Debian/Linux Sarge at
home. (Behaviour is same when using Gnus v.10.5.7)

I used to be able to connect via an intermediate host to a newsserver
at university, as follows:

(setq gnus-select-method 
      '(nntp "news.media.kyoto-u.ac.jp"
             (nntp-open-connection-function nntp-open-via-rlogin-and-telnet)
             (nntp-via-address "rasc6.rish.kyoto-u.ac.jp")
             (nntp-via-user-name "ismail")
             (nntp-via-rlogin-command "ssh")
             (nntp-via-rlogin-command-switches ("-C"))
             (nntp-telnet-command "telnet")
;;           (nntp-telnet-switches ("-8"))
;;           (nntp-port-number "119")
             (nntp-address "news.media.kyoto-u.ac.jp")
             (nntp-end-of-line "\n")
            ))

This worked with the nntp-via-rlogin-command-switches set to various,
such as ("-C") or ("-C" "-2" "-x" "-t" "-e" "none"). Also, the
nntp-telnet-switches and nntp-port-number settings are optional, since
they represent the default in gnus (set in nntp.el).

I have ssh-agent running, and use assymetric keys, one of which is
copied to the ~/.ssh directory on the intermediate host.

Occasionally, the server would not be reachable. This was not
surprising, since the machine is sometimes down. However, recently I
cannot connect at all from home. This is strange, because I do not
think I changed any settings (but I cannot say for sure). What I have
is a router connected to a DSL line, and my home machine is hanging
off the router with a 192.168.X.X address while the router does NAT. I
do not tell gnus about this, perhaps that is in error?

I can do from the shell prompt of my home machine the following:

ssh -C -l ismail rasc6.rish.kyoto-u.ac.jp telnet -8 news.media.kyoto-u.ac.jp 119
Trying 130.54.14.3...
Connected to news.media.kyoto-u.ac.jp.
Escape character is '^]'.
200 news.media.kyoto-u.ac.jp InterNetNews NNRP server INN 2.4.1 ready (posting 
ok).
quit
205 .
Connection closed by foreign host.

So clearly the connection does work via ssh and telnet. If I leave out
the -8 the connection still works fine. There does not seem to be any
explicit "telnet>" prompt though, which is something it seems the
nntp-open-via-rlogin-and-telnet waits for.

I then tried to debug using edebug (first time user, so I am still
confused by how to do this well), using M-x edebug-defun RET in the
nntp-open-via-rlogin-and-telnet function in nntp.el, and then using
SPC to go through the connection line by line. I get to the point
where nntpd is started, with the arguments given by the parameters (I
note that the nntp-port-number, and nntp-address are not given as
arguments to nntpd) but nntpd returns a "cannot open
nntp:media.kyoto-u.ac.jp go offline: y/n" type message.

Now I am not sure how to proceed. edebug showed me that my parameters
are set up and passed on, but I can still not find out the
error. Nothing in the *Messages* buffer.

Any comments and idea on how to proceed are welcome!
Many thanks,
     Gernot
-- 
G Hassenpflug RASC, Kyoto University