Thank you, Comcast.
swmike at swm.pp.se
Fri Feb 26 06:20:28 UTC 2016
On Thu, 25 Feb 2016, Jared Mauch wrote:
> Make sure you permit TCP/53 for DNS queries so if TC=1 lookups work.
Speaking of which, historically ISPs have been blocking TCP/135, TCP/445
and a few others towards customers (at least that's what I know). TCP/25
seems to be blocked as well.
Why isn't UDP/53 blocked towards customers? I know historically there were
resolvers that used UDP/53 as source port for queries, but is this the
I know providers that have blocked UDP/53 towards customers as a
countermeasure to the amplification attacks. As far as I heard, there were
no customer complaints.
Mikael Abrahamsson email: swmike at swm.pp.se
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