tug.ctan.org inaccessible on a specific machine

[Stuart Little]

Thank you very much for all the help!

I have confirmed that as I write this, the block has been lifted (I am getting responses to pings). 

On Fri, Apr 02, 2021 at 09:27:37AM -0600, Nelson H. F. Beebe wrote:
> Stuart Little <achirvasub at gmail.com> reported yesterday on this list
> that he was unable to reach tug.ctan.org from a machine in the
> DigitalOcean cloud, and the block was still in place today.
> 
> I searched incoming connection logs at our site, and found no mention
> of his address.  Next, I checked the campus boundary IP-blocked list,
> and did not find it there either.
> 
> I then spoke to our departmental firewall administrator, and found
> that machines in the DigitalOcean domain 142.93.*.* have been frequent
> sources of ssh login attacks, and so a block against that IP space had
> been imposed in our firewall.  The DigitalOcean block has now been
> removed, but because of the attack patterns, may have to go up again.
> 
> This seems to be a common issue with virtual machines supplied by
> various cloud services: good guys use them to do useful work at low
> cost, but bad guys view them as an untrackable way to launch attacks.
> At present, there does not seem to be a good solution to that problem.
> 
> 
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> - University of Utah                    FAX: +1 801 581 4148                  -
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