Some servers on a server provider won't connect to a site

Fluffy asked:

I have a bunch of servers on online.net, and while debugging a certain issue, I’ve found that some of them won’t connect to some websites, which are online and reachable from the other servers.

For example, this one: baniancitynews.com. I can open it locally, isup.me also shows it as “up”, but every server on online.net that is in 163.172.*.* IP range won’t open it (other servers by online.net work fine). Here’s an example output of mtr --report:

HOST: sssss                       Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 163-172-80-1.rev.poneytel  0.0%    10    0.2   0.3   0.2   0.4   0.0
  2.|-- 195.154.2.131              0.0%    10    0.4   0.5   0.4   0.7   0.0
  3.|-- a9k1-pni-th2.dc3.poneytel  0.0%    10    0.7   0.7   0.4   0.9   0.0
  4.|-- be4751.rcr21.b022890-0.pa  0.0%    10    0.8   0.8   0.7   1.0   0.0
  5.|-- be3190.ccr31.par04.atlas.  0.0%    10    1.2   1.2   1.1   1.5   0.0
  6.|-- be3183.ccr41.par01.atlas.  0.0%    10    1.6   1.6   1.5   1.7   0.0
  7.|-- be3092.ccr21.mrs01.atlas.  0.0%    10   12.3  12.4  12.2  12.7   0.0
  8.|-- 149.6.155.182              0.0%    10   12.2  12.2  12.2  12.4   0.0
  9.|-- 182.79.175.45              0.0%    10  152.1 153.0 152.1 159.9   2.4
 10.|-- 182.74.51.222              0.0%    10  152.4 151.8 149.3 166.1   5.2
 11.|-- ???                       100.0    10    0.0   0.0   0.0   0.0   0.0

I was told that the problem is not in online.net’s network, so there is nothing they can do.

How should I understand it? The remote network for some reason doesn’t like requests from 163.172.*.*, so it doesn’t handle them?

My answer:


If the remote server blacklisted that IP address range in its firewall, then nothing from that IP address range will be able to connect. This is not something that Online.net can fix. You should send email to the site webmaster.


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