AT&T blocking port 123
halmurray at sonic.net
Fri Aug 5 20:09:54 UTC 2022
Does anybody have an AT&T residential account?
Google gets lots of hits on the subject.
Their forums have several comments similar to this one:
> No, Port 123 is restricted both ways on residential AT&T accounts because
> it's a known DDoS risk.
With no help at all for how to get time.
That links to:
Down at the bottom is a table of the ports they block which says they block
port 123 in both directions.
>From another thread:
> AT&T performs source port blocking for port 123 for traffic coming from
> endpoints in its network. It allows requests to go to servers on port 123.
> NTP peers use both a source and a destination port of 123, so this would
> typically block traffic.
[But if you go through NAT, the internal source port gets translated so it
I'm a bit surprised I haven't heard about this before. Is this well known and
I just, somehow, missed it?
These are my opinions. I hate spam.
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