Fkiws with destination port 0 and TCP SYN flag set

Marcin Cieslak saper at saper.info
Wed Jun 17 09:30:47 UTC 2015


On Wed, 17 Jun 2015, Maqbool Hashim wrote:

> It is always the same destination servers and in normal operations
> these source and destination hosts do have a bunch of legitimate flows
> between them.  I was leaning towards it being a reporting artifact,
> but it's interesting that there are a whole set of Ack Reset packets
> from the destination hosts with a source port of 0 also.

So the destination host is sending ACK+RST with the *source* port
set to zero, or the *destination* port?

> Does this not indicate that it probably isn't a reporting artifact?

I would just tcpdump on one of the source machines to find out.

~Marcin



More information about the NANOG mailing list