nanog mailing list archives

Re: where to go to understand DDoS attack vector


From: Roland Dobbins <rdobbins () arbor net>
Date: Tue, 26 Aug 2014 20:58:08 +0700


On Aug 26, 2014, at 8:37 PM, John York <johny () griffintechnology com> wrote:

In this case, 17 is both the protocol and port number. Confusing coincidence :)

Not in this output which the OP sent to the list:

8:33:58.482193 IP (tos 0x0, ttl 56, id 0, offset 0, flags [DF], proto UDP (17), length 29) x.x.x.x.2072 > 
x.x.x.x.27015: UDP, length 1
               0x0000: 4500 001d 0000 4000 3811 088c cf9a 3b8c E.....@.8 <mailto:E.....@.8>.....;.
               0x0010: 405e eebf 0818 6987 0009 10f8 4300 0000 @^....i.....C...
               0x0020: 0000 0000 0000 0000 0000 0000 0000       ..............


18:33:58.482193 IP (tos 0x0, ttl 56, id 0, offset 0, flags [DF], proto UDP (17), length 29) x.x.x.x.2072 > 
x.x.x.x.27015: UDP, length 1
               0x0000: 4500 001d 0000 4000 3811 088c cf9a 3b8c E.....@.8 <mailto:E.....@.8>.....;.
               0x0010: 405e eebf 0818 6987 0009 10f8 4300 0000 @^....i.....C...
               0x0020: 0000 0000 0000 0000 0000 0000 0000       ..............
18:33:58.484625 IP (tos 0x0, ttl 56, id 0, offset 0, flags [DF], proto UDP (17), length 29) x.x.x.x.2072 > 
x.x.x.x.27015: UDP, length 1
               0x0000: 4500 001d 0000 4000 3811 088c cf9a 3b8c E.....@.8 <mailto:E.....@.8>.....;.
               0x0010: 405e eebf 0818 6987 0009 10f8 4300 0000 @^....i.....C...
               0x0020: 0000 0000 0000 0000 0000 0000 0000       ..............
18:33:58.486137 IP (tos 0x0, ttl 56, id 0, offset 0, flags [DF], proto UDP (17), length 29) x.x.x.x.2072 > 
x.x.x.x.27015: UDP, length 1
               0x0000: 4500 001d 0000 4000 3811 088c cf9a 3b8c E.....@.8 <mailto:E.....@.8>.....;.
               0x0010: 405e eebf 0818 6987 0009 10f8 4300 0000 @^....i.....C...
               0x0020: 0000 0000 0000 0000 0000 0000 0000       ..............

Source port 2072, destination port 27015.

----------------------------------------------------------------------
Roland Dobbins <rdobbins () arbor net> // <http://www.arbornetworks.com>

                   Equo ne credite, Teucri.

                          -- Laocoön


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