ISP port blocking practice

Lyndon Nerenberg (VE6BBM/VE7TFX) lyndon at orthanc.ca
Fri Oct 23 17:15:23 UTC 2009


> Rogers 
> says they don't do that, and lots of other people seem to be able to
> use port 587 on Rogers (and other ISPs) without problems.

I'm in Calgary right now so I can't check the current behaviour, but
as of June 1st it was still broken.  Broken in the sense that any
connection to port 587 would go through, but the AUTH lines in the
EHLO response get deleted.  They're obviously hijacking the connections
through a broken proxy.  And port 587 without AUTH is useless.

As for outright blockage of port 587, I get this complaint from many of
my clients while they are on the road. It seems hotels love to block it.

--lyndon





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