apt-get issue(s)

[Kenneth Pronovici <pronovic@skyjammer.com>]

I'm cross-posting this to user and security, because there are really two
(possibly-related) issues here.  Feel free to take replies to just one list
or the other.

On my firewall (running potato), I have been using these apt sources.list 
entries:

   deb http://security.debian.org potato/updates main contrib non-free
   deb http://http.us.debian.org/debian/ potato main non-free contrib
   deb http://non-us.debian.org/debian-non-US/ potato/non-US main contrib non-free

However, suddenly, 'apt-get update' started failing with errors of the form:

   Err http://security.debian.org potato/updates/main Packages
     Could not connect to security.debian.org (132.229.131.40).

for each of the entries.  I've finally worked around this by using these
sources.list entries:

   deb ftp://security.debian.org/debian-security potato/updates main contrib non-free
   deb ftp://http.us.debian.org/debian/ potato main non-free contrib
   deb ftp://non-us.debian.org/debian-non-US/ potato/non-US main contrib non-free

First question: any idea why the original http source.list entries suddenly 
stopped working?  The URLs that apt-get complains about seem to be available
via lynx, so connectivity is apparently not the issue.  Running strace on 
'apt-get update' shows me an error "400 URI Failure", but I'm not sure where 
that leads me.  I can go dig through the code next, but...

Second question: what's up with the security URL that I needed for FTP?  I 
would have expected to use "ftp://security.debian.org";, but the "dists" 
directory exists under "ftp://security.debian.org/debian-security"; instead.

Thanks in advance for the information.  I guess I've worked around this for
now, but I'd like to know what happened.

KEN

-- 
Kenneth J. Pronovici <pronovic@ieee.org>
Personal Homepage: http://www.skyjammer.com/~pronovic/
"I have zero tolerance for zero-tolerance policies."