28 Apr
2017
28 Apr
'17
12:32 a.m.
That is the Mirkotik discovery protocol indeed. I struggled with this too at first until I
found that you can enable/disable it on select interfaces. By default it sends and listens
on all interfaces. I'll post a small tutorial on where to find and disable it per
interface when I arrive at work (unless someone beats me to it)
I also firewalled in&outbound that on all but my internal interfaces just to be extra
certain. I would recomend everyone doing so too unless you need it for some reason on an
external interface.
Like with Cisco's CDP or Juniper's LLDP, you normally don't need it on
external interfaces.
Ruben - ON3RVH
On 28 Apr 2017, at 02:23, Brian Kantor
<Brian(a)UCSD.Edu> wrote:
(Please trim inclusions from previous messages)
_______________________________________________
Once a minute, at 8 seconds past the minute, gateway 77.138.34.39
sends an encapped UDP packet to the amprgw router that has a zero inner
source address and an all-ones inner destination address. The payload
length is 94 bytes and the source and destination ports are both 5678.
The periodicity suggests that it's some process that runs every minute
(out of crontab?) and takes about 8 seconds to complete.
There is a list of things port 5678 may be used for at
http://www.speedguide.net/port.php?port=5678
This may be Mikrotik Neighbor Discovery protocol.
Here's a log record of one such packet:
Apr 27 17:02:08 <local0.info> amprgw ipipd[22702]: ISRC0: len 122, os 77.138.34.39,
od 169.228.66.251, is 0.0.0.0, id 255.255.255.255, ttl 64, proto 17
And here's a tcpdump of one:
17:06:08.419945 IP (tos 0x0, ttl 242, id 36314, offset 0, flags [none], proto IPIP (4),
length 142)
77.138.34.39 > 169.228.66.251: IP (tos 0x0, ttl 64, id 0, offset 0, flags [none],
proto UDP (17), length 122)
0.0.0.0.5678 > 255.255.255.255.5678: UDP, length 94
The portal record shows that this gateway belongs to Ronen Pinchuk [4Z4ZQ].
Ronen, when you have a few spare minutes, could you look at your gateway
and see if you can stop this from happening?
- Brian
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