Dear Mr(s) Network Engineer Please Check Thy Config…SDN is a coming!!!

A quick question out there to all you network engineers – how long does it take to verify a ‘simple’ firewall configuration when you’ve access to the firewall configs? Let’s say tens of minutes at a maximum.

Now, how long does it take mere mortals like me (third party OpenStack installation engineer) , to prove that you’ve configured you’re firewall incorrectly with very limited access to the same environment – Answer: Five and a half hours today.

This delay is one of the fundamental reasons why we need automation and SDNs.

Anyhow, enough moaning on my part – what today’s post is about is the steps I used to verify the communication issue – again no rocket science here but for non network engineering folks this may come in useful.

I had a management network which was on 10.12.25.0/24 and an IPMI metwork on 10.10.148.45/24

One of the first indicators of an issue was when I tried to verify the communication between both networks using the IPMI tool. The CreateBareMetal.py script ran without an issue verifying http and maybe ssh (I need to check the script). However the output from the following IPMItool command:

ipmitool -I lanplus -H 10.10.148.45 -U helion -P helion -R 12 -N 5 power status

Resulted in this communication error:

Error: Unable to establish IPMI v2 / RMCP+ session
Error: Unable to establish IPMI v2 / RMCP+ session

The ports and protocols that are required to be opened between both networks for the installation to complete successfully are:

Protocols - TCP & UDP
Ports - 22, 80, 443, 623, 17988, 17990

The NetCat tool (nc) is very useful for testing network connectivity.
Test all TCP ports with the following command:

nc -zv 10.10.148.44 22 80 443 623 17990 17988

which returns:

10.10.148.44: inverse host lookup failed: Unknown host
(UNKNOWN) [10.10.148.44] 22 (ssh) open
(UNKNOWN) [10.10.148.44] 80 (http) open
(UNKNOWN) [10.10.148.44] 443 (https) open
(UNKNOWN) [10.10.148.44] 17990 (?) open
(UNKNOWN) [10.10.148.44] 17988 (?) open

Note that there was no response from port 623 on TCP as this RMCP service does not use TCP.

Simply add a ‘u’ option to test the UDP ports as follows:

nc -zvu 10.10.148.44 22 80 443 623 17990 17988

The result is as follows:

10.10.148.44: inverse host lookup failed: Unknown host
(UNKNOWN) [10.10.148.44] 22 (ssh) open
(UNKNOWN) [10.10.148.44] 80 (http) open
(UNKNOWN) [10.10.148.44] 443 (https) open
(UNKNOWN) [10.10.148.44] 623 (asf-rmcp) open
(UNKNOWN) [10.10.148.44] 17990 (?) open
(UNKNOWN) [10.10.148.44] 17988 (?) open

So yes, I can hear everyone saying so “what’s the problem? UDP port 623 is working”…well we’ve only tested from one side of the network and I didn’t have access to the IPMI network 😦

So my next tool of choice was TCPDUMP.
I configured this to monitor all the communication across the interface to see if this could help me to demonstrate the issue better…and it did!

Open up two console session – one for the ipmitool command and the other one to execute the tcpdump command.

The following command listens for all communication across all interfaces on port 623 – I could have narrowed this down to a single interface by replacing ‘any’ with the interface name e.g. ‘eth0’.

tcpdump -vv -x -X -s 1500 -i any 'port 623'

Again the ipmitool command which was run in the second console window was:

ipmitool -I lanplus -H 10.10.148.45 -U helion -P helion -R 12 -N 5 power status

This resulted in the following tcpdump:

tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture size 1500 bytes
19:03:06.385209 IP (tos 0x0, ttl 64, id 16502, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc360 -> 0x540f!] UDP, length 23
        0x0000:  4500 0033 4076 4000 4011 3714 0afe 190c  E..3@v@.@.7.....
        0x0010:  0af9 942d b519 026f 001f c360 0600 ff07  ...-...o...`....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:03:06.385757 IP (tos 0x0, ttl 64, id 16502, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [udp sum ok] UDP, length 23
        0x0000:  4500 0033 4076 4000 4011 3714 0afe 190c  E..3@v@.@.7.....
        0x0010:  0af9 942d b519 026f 001f 540f 0600 ff07  ...-...o..T.....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:03:11.395994 IP (tos 0x0, ttl 64, id 16748, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc360 -> 0x540f!] UDP, length 23
        0x0000:  4500 0033 416c 4000 4011 361e 0afe 190c  E..3Al@.@.6.....
        0x0010:  0af9 942d b519 026f 001f c360 0600 ff07  ...-...o...`....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:03:11.396009 IP (tos 0x0, ttl 64, id 16748, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc360 -> 0x540f!] UDP, length 23
        0x0000:  4500 0033 416c 4000 4011 361e 0afe 190c  E..3Al@.@.6.....
        0x0010:  0af9 942d b519 026f 001f c360 0600 ff07  ...-...o...`....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:03:17.407388 IP (tos 0x0, ttl 64, id 17814, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc360 -> 0x540f!] UDP, length 23
        0x0000:  4500 0033 4596 4000 4011 31f4 0afe 190c  E..3E.@.@.1.....
        0x0010:  0af9 942d b519 026f 001f c360 0600 ff07  ...-...o...`....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:03:17.407603 IP (tos 0x0, ttl 64, id 17814, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [udp sum ok] UDP, length 23
        0x0000:  4500 0033 4596 4000 4011 31f4 0afe 190c  E..3E.@.@.1.....
        0x0010:  0af9 942d b519 026f 001f 540f 0600 ff07  ...-...o..T.....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:03:24.419809 IP (tos 0x0, ttl 64, id 19491, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.46361 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc360 -> 0x540f!] UDP, length 23
        0x0000:  4500 0033 4c23 4000 4011 2b67 0afe 190c  E..3L#@.@.+g....
        0x0010:  0af9 942d b519 026f 001f c360 0600 ff07  ...-...o...`....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...

Yes, this always looks like gibberish (technical term) to me too initially.
The important feature to notice from this output is that there is never a response. Communication is not bi-directional!
Once I showed this to the network team they miraculously discoverd an error in the previously verified firewall config!!! UDP was only permitted in one direction. When this mis-configuration was rectified everything sprung into life.

So this is what the output looks like when everything is working:

ipmitool -I lanplus -H 10.10.148.45 -U helion -P helion -R 12 -N 5 power status
Chassis Power is off

And the good tcpdump:

 tcpdump -vv -x -X -s 1500 -i any 'port 623'
tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture size 1500 bytes
19:41:59.208265 IP (tos 0x0, ttl 64, id 13674, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc360 -> 0x6abc!] UDP, length 23
        0x0000:  4500 0033 356a 4000 4011 4220 0afe 190c  E..35j@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 001f c360 0600 ff07  ...-.l.o...`....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:41:59.208548 IP (tos 0x0, ttl 64, id 13674, offset 0, flags [DF], proto UDP (17), length 51)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [udp sum ok] UDP, length 23
        0x0000:  4500 0033 356a 4000 4011 4220 0afe 190c  E..35j@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 001f 6abc 0600 ff07  ...-.l.o..j.....
        0x0020:  0000 0000 0000 0000 0009 2018 c881 0038  ...............8
        0x0030:  8e04 b5                                  ...
19:41:59.210415 IP (tos 0x0, ttl 60, id 25021, offset 0, flags [none], proto UDP (17), length 58)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 30
        0x0000:  4500 003a 61bd 0000 3c11 59c6 0af9 942d  E..:a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0026 2fe3 0600 ff07  .....o.l.&/.....
        0x0020:  0000 0000 0000 0000 0010 811c 6320 0038  ............c..8
        0x0030:  0002 8014 0200 0000 0010                 ..........
19:41:59.210566 IP (tos 0x0, ttl 60, id 25021, offset 0, flags [none], proto UDP (17), length 58)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 30
        0x0000:  4500 003a 61bd 0000 3c11 59c6 0af9 942d  E..:a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0026 2fe3 0600 ff07  .....o.l.&/.....
        0x0020:  0000 0000 0000 0000 0010 811c 6320 0038  ............c..8
        0x0030:  0002 8014 0200 0000 0010                 ..........
19:41:59.210757 IP (tos 0x0, ttl 64, id 13675, offset 0, flags [DF], proto UDP (17), length 76)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc379 -> 0x22fe!] UDP, length 48
        0x0000:  4500 004c 356b 4000 4011 4206 0afe 190c  E..L5k@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 0038 c379 0600 ff07  ...-.l.o.8.y....
        0x0020:  0610 0000 0000 0000 0000 2000 0000 0000  ................
        0x0030:  a4a3 a2a0 0000 0008 0100 0000 0100 0008  ................
        0x0040:  0100 0000 0200 0008 0100 0000            ............
19:41:59.210768 IP (tos 0x0, ttl 64, id 13675, offset 0, flags [DF], proto UDP (17), length 76)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc379 -> 0x22fe!] UDP, length 48
        0x0000:  4500 004c 356b 4000 4011 4206 0afe 190c  E..L5k@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 0038 c379 0600 ff07  ...-.l.o.8.y....
        0x0020:  0610 0000 0000 0000 0000 2000 0000 0000  ................
        0x0030:  a4a3 a2a0 0000 0008 0100 0000 0100 0008  ................
        0x0040:  0100 0000 0200 0008 0100 0000            ............
19:41:59.211843 IP (tos 0x0, ttl 60, id 25022, offset 0, flags [none], proto UDP (17), length 80)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 52
        0x0000:  4500 0050 61be 0000 3c11 59af 0af9 942d  E..Pa...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 003c 785e 0600 ff07  .....o.l.<x^....
        0x0020:  0611 0000 0000 0000 0000 2400 0000 0400  ..........$.....
        0x0030:  a4a3 a2a0 9796 0b00 0000 0008 0100 0000  ................
        0x0040:  0100 0008 0100 0000 0200 0008 0100 0000  ................
19:41:59.211843 IP (tos 0x0, ttl 60, id 25022, offset 0, flags [none], proto UDP (17), length 80)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 52
        0x0000:  4500 0050 61be 0000 3c11 59af 0af9 942d  E..Pa...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 003c 785e 0600 ff07  .....o.l.<x^....
        0x0020:  0611 0000 0000 0000 0000 2400 0000 0400  ..........$.....
        0x0030:  a4a3 a2a0 9796 0b00 0000 0008 0100 0000  ................
        0x0040:  0100 0008 0100 0000 0200 0008 0100 0000  ................
19:41:59.212088 IP (tos 0x0, ttl 64, id 13676, offset 0, flags [DF], proto UDP (17), length 78)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc37b -> 0x0d95!] UDP, length 50
        0x0000:  4500 004e 356c 4000 4011 4203 0afe 190c  E..N5l@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 003a c37b 0600 ff07  ...-.l.o.:.{....
        0x0020:  0612 0000 0000 0000 0000 2200 0000 0000  ..........".....
        0x0030:  9796 0b00 1709 f67a b5e7 2c48 3217 ca55  .......z..,H2..U
        0x0040:  7036 098e 1400 0006 6865 6c69 6f6e       p6......helion
19:41:59.212096 IP (tos 0x0, ttl 64, id 13676, offset 0, flags [DF], proto UDP (17), length 78)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc37b -> 0x0d95!] UDP, length 50
        0x0000:  4500 004e 356c 4000 4011 4203 0afe 190c  E..N5l@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 003a c37b 0600 ff07  ...-.l.o.:.{....
        0x0020:  0612 0000 0000 0000 0000 2200 0000 0000  ..........".....
        0x0030:  9796 0b00 1709 f67a b5e7 2c48 3217 ca55  .......z..,H2..U
        0x0040:  7036 098e 1400 0006 6865 6c69 6f6e       p6......helion
19:41:59.252474 IP (tos 0x0, ttl 60, id 25023, offset 0, flags [none], proto UDP (17), length 104)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 76
        0x0000:  4500 0068 61bf 0000 3c11 5996 0af9 942d  E..ha...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0054 a522 0600 ff07  .....o.l.T."....
        0x0020:  0613 0000 0000 0000 0000 3c00 0000 0000  ..........<.....
        0x0030:  a4a3 a2a0 a42f 0000 9f49 0000 224c 0000  ...../...I.."L..
        0x0040:  f709 0000 3634 3130 3136 435a 4a32 3339  ....641016CZJ239
        0x0050:  3050 5233 b5fe 99c6 eacf 0d52 10c1 f079  0PR3.......R...y
        0x0060:  6951 5aba c47b 5d5b                      iQZ..{][
19:41:59.252474 IP (tos 0x0, ttl 60, id 25023, offset 0, flags [none], proto UDP (17), length 104)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 76
        0x0000:  4500 0068 61bf 0000 3c11 5996 0af9 942d  E..ha...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0054 a522 0600 ff07  .....o.l.T."....
        0x0020:  0613 0000 0000 0000 0000 3c00 0000 0000  ..........<.....
        0x0030:  a4a3 a2a0 a42f 0000 9f49 0000 224c 0000  ...../...I.."L..
        0x0040:  f709 0000 3634 3130 3136 435a 4a32 3339  ....641016CZJ239
        0x0050:  3050 5233 b5fe 99c6 eacf 0d52 10c1 f079  0PR3.......R...y
        0x0060:  6951 5aba c47b 5d5b                      iQZ..{][
19:41:59.252598 IP (tos 0x0, ttl 64, id 13680, offset 0, flags [DF], proto UDP (17), length 72)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc375 -> 0x9722!] UDP, length 44
        0x0000:  4500 0048 3570 4000 4011 4205 0afe 190c  E..H5p@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 0034 c375 0600 ff07  ...-.l.o.4.u....
        0x0020:  0614 0000 0000 0000 0000 1c00 0000 0000  ................
        0x0030:  9796 0b00 d7bc d2ac 2672 8d5a f9d9 3d58  ........&r.Z..=X
        0x0040:  0fbe 7cbe 5c56 bc69                      ..|.\V.i
19:41:59.252604 IP (tos 0x0, ttl 64, id 13680, offset 0, flags [DF], proto UDP (17), length 72)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc375 -> 0x9722!] UDP, length 44
        0x0000:  4500 0048 3570 4000 4011 4205 0afe 190c  E..H5p@.@.B.....
        0x0010:  0af9 942d 9e6c 026f 0034 c375 0600 ff07  ...-.l.o.4.u....
        0x0020:  0614 0000 0000 0000 0000 1c00 0000 0000  ................
        0x0030:  9796 0b00 d7bc d2ac 2672 8d5a f9d9 3d58  ........&r.Z..=X
        0x0040:  0fbe 7cbe 5c56 bc69                      ..|.\V.i
19:41:59.256108 IP (tos 0x0, ttl 60, id 25024, offset 0, flags [none], proto UDP (17), length 64)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 36
        0x0000:  4500 0040 61c0 0000 3c11 59bd 0af9 942d  E..@a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 002c 0a95 0600 ff07  .....o.l.,......
        0x0020:  0615 0000 0000 0000 0000 1400 0000 0000  ................
        0x0030:  a4a3 a2a0 3063 d88f 4193 f566 a90d 4199  ....0c..A..f..A.
19:41:59.256108 IP (tos 0x0, ttl 60, id 25024, offset 0, flags [none], proto UDP (17), length 64)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 36
        0x0000:  4500 0040 61c0 0000 3c11 59bd 0af9 942d  E..@a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 002c 0a95 0600 ff07  .....o.l.,......
        0x0020:  0615 0000 0000 0000 0000 1400 0000 0000  ................
        0x0030:  a4a3 a2a0 3063 d88f 4193 f566 a90d 4199  ....0c..A..f..A.
19:41:59.256241 IP (tos 0x0, ttl 64, id 13681, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0x22bc!] UDP, length 64
        0x0000:  4500 005c 3571 4000 4011 41f0 0afe 190c  E..\5q@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0300 0000 2000 ca78 4898  .............xH.
        0x0030:  cd92 a415 694e 7eb3 20b2 deda 7815 b787  ....iN~.....x...
        0x0040:  f361 77b7 106d eb29 92b5 0a2b ffff 0207  .aw..m.)...+....
        0x0050:  152d c47a 3ee2 d910 9a20 79fe            .-.z>.....y.
19:41:59.256248 IP (tos 0x0, ttl 64, id 13681, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0x22bc!] UDP, length 64
        0x0000:  4500 005c 3571 4000 4011 41f0 0afe 190c  E..\5q@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0300 0000 2000 ca78 4898  .............xH.
        0x0030:  cd92 a415 694e 7eb3 20b2 deda 7815 b787  ....iN~.....x...
        0x0040:  f361 77b7 106d eb29 92b5 0a2b ffff 0207  .aw..m.)...+....
        0x0050:  152d c47a 3ee2 d910 9a20 79fe            .-.z>.....y.
19:41:59.261371 IP (tos 0x0, ttl 60, id 25025, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c1 0000 3c11 59a0 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 35e0 0600 ff07  .....o.l.H5.....
        0x0020:  06c0 a4a3 a2a0 0100 0000 2000 b216 0000  ................
        0x0030:  a74c 0000 3960 0000 983b 0000 6819 6f28  .L..9`...;..h.o(
        0x0040:  56ae 2e17 b16b b95b d5b1 4e39 ffff 0207  V....k.[..N9....
        0x0050:  5e18 55e6 5c4c 6b69 18af 4542            ^.U.\Lki..EB
19:41:59.261371 IP (tos 0x0, ttl 60, id 25025, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c1 0000 3c11 59a0 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 35e0 0600 ff07  .....o.l.H5.....
        0x0020:  06c0 a4a3 a2a0 0100 0000 2000 b216 0000  ................
        0x0030:  a74c 0000 3960 0000 983b 0000 6819 6f28  .L..9`...;..h.o(
        0x0040:  56ae 2e17 b16b b95b d5b1 4e39 ffff 0207  V....k.[..N9....
        0x0050:  5e18 55e6 5c4c 6b69 18af 4542            ^.U.\Lki..EB
19:41:59.261489 IP (tos 0x0, ttl 64, id 13682, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0xb4ed!] UDP, length 64
        0x0000:  4500 005c 3572 4000 4011 41ef 0afe 190c  E..\5r@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0400 0000 2000 6c3a 4b11  ............l:K.
        0x0030:  337a a6f0 1cb1 dc1a 35d6 b17f 7c09 1d95  3z......5...|...
        0x0040:  f01c 7a8c c066 782f 76bf d495 ffff 0207  ..z..fx/v.......
        0x0050:  4b0d 880a 5742 cb10 f431 2e56            K...WB...1.V
19:41:59.261496 IP (tos 0x0, ttl 64, id 13682, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0xb4ed!] UDP, length 64
        0x0000:  4500 005c 3572 4000 4011 41ef 0afe 190c  E..\5r@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0400 0000 2000 6c3a 4b11  ............l:K.
        0x0030:  337a a6f0 1cb1 dc1a 35d6 b17f 7c09 1d95  3z......5...|...
        0x0040:  f01c 7a8c c066 782f 76bf d495 ffff 0207  ..z..fx/v.......
        0x0050:  4b0d 880a 5742 cb10 f431 2e56            K...WB...1.V
19:41:59.266049 IP (tos 0x0, ttl 60, id 25026, offset 0, flags [none], proto UDP (17), length 108)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 80
        0x0000:  4500 006c 61c2 0000 3c11 598f 0af9 942d  E..la...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0058 56f0 0600 ff07  .....o.l.XV.....
        0x0020:  06c0 a4a3 a2a0 0200 0000 3000 026c 0000  ..........0..l..
        0x0030:  d948 0000 0b6f 0000 2760 0000 394b d1aa  .H...o..'`..9K..
        0x0040:  378d db9d 3e8e 0e4f 2e96 2b5c 602d d1b4  7...>..O..+\`-..
        0x0050:  c158 b131 d0f6 df8d 32b9 35ce ffff 0207  .X.1....2.5.....
        0x0060:  50cc 023a 68e5 78b9 f999 fe01            P..:h.x.....
19:41:59.266049 IP (tos 0x0, ttl 60, id 25026, offset 0, flags [none], proto UDP (17), length 108)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 80
        0x0000:  4500 006c 61c2 0000 3c11 598f 0af9 942d  E..la...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0058 56f0 0600 ff07  .....o.l.XV.....
        0x0020:  06c0 a4a3 a2a0 0200 0000 3000 026c 0000  ..........0..l..
        0x0030:  d948 0000 0b6f 0000 2760 0000 394b d1aa  .H...o..'`..9K..
        0x0040:  378d db9d 3e8e 0e4f 2e96 2b5c 602d d1b4  7...>..O..+\`-..
        0x0050:  c158 b131 d0f6 df8d 32b9 35ce ffff 0207  .X.1....2.5.....
        0x0060:  50cc 023a 68e5 78b9 f999 fe01            P..:h.x.....
19:41:59.266160 IP (tos 0x0, ttl 64, id 13683, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0x4df1!] UDP, length 64
        0x0000:  4500 005c 3573 4000 4011 41ee 0afe 190c  E..\5s@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0500 0000 2000 f766 8004  .............f..
        0x0030:  f24a b265 8b00 6a19 c808 6b40 5c61 3f58  .J.e..j...k@\a?X
        0x0040:  06b2 4cf8 fb42 134b b9c0 c9b9 ffff 0207  ..L..B.K........
        0x0050:  79b2 96e1 01a2 7e98 548b ccb5            y.....~.T...
19:41:59.266168 IP (tos 0x0, ttl 64, id 13683, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0x4df1!] UDP, length 64
        0x0000:  4500 005c 3573 4000 4011 41ee 0afe 190c  E..\5s@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0500 0000 2000 f766 8004  .............f..
        0x0030:  f24a b265 8b00 6a19 c808 6b40 5c61 3f58  .J.e..j...k@\a?X
        0x0040:  06b2 4cf8 fb42 134b b9c0 c9b9 ffff 0207  ..L..B.K........
        0x0050:  79b2 96e1 01a2 7e98 548b ccb5            y.....~.T...
19:41:59.270586 IP (tos 0x0, ttl 60, id 25027, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c3 0000 3c11 599e 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 1d7e 0600 ff07  .....o.l.H.~....
        0x0020:  06c0 a4a3 a2a0 0300 0000 2000 b940 0000  .............@..
        0x0030:  a12e 0000 5c72 0000 c47a 0000 1992 d8c0  ....\r...z......
        0x0040:  8a88 d725 86d3 3dae 5b9f f2c0 ffff 0207  ...%..=.[.......
        0x0050:  9713 723a 3296 99c1 be87 8f53            ..r:2......S
19:41:59.270586 IP (tos 0x0, ttl 60, id 25027, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c3 0000 3c11 599e 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 1d7e 0600 ff07  .....o.l.H.~....
        0x0020:  06c0 a4a3 a2a0 0300 0000 2000 b940 0000  .............@..
        0x0030:  a12e 0000 5c72 0000 c47a 0000 1992 d8c0  ....\r...z......
        0x0040:  8a88 d725 86d3 3dae 5b9f f2c0 ffff 0207  ...%..=.[.......
        0x0050:  9713 723a 3296 99c1 be87 8f53            ..r:2......S
19:41:59.270709 IP (tos 0x0, ttl 64, id 13684, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0xdd9e!] UDP, length 64
        0x0000:  4500 005c 3574 4000 4011 41ed 0afe 190c  E..\5t@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0600 0000 2000 6bed 4fa0  ............k.O.
        0x0030:  ebc5 73ec 0c44 a0e3 78d3 5bdb 8150 61fb  ..s..D..x.[..Pa.
        0x0040:  209a ecab d02a db3c 06e6 0508 ffff 0207  .....*.<........
        0x0050:  665f dbef 1767 a7be f874 a865            f_...g...t.e
19:41:59.270717 IP (tos 0x0, ttl 64, id 13684, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0xdd9e!] UDP, length 64
        0x0000:  4500 005c 3574 4000 4011 41ed 0afe 190c  E..\5t@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0600 0000 2000 6bed 4fa0  ............k.O.
        0x0030:  ebc5 73ec 0c44 a0e3 78d3 5bdb 8150 61fb  ..s..D..x.[..Pa.
        0x0040:  209a ecab d02a db3c 06e6 0508 ffff 0207  .....*.<........
        0x0050:  665f dbef 1767 a7be f874 a865            f_...g...t.e
19:41:59.278401 IP (tos 0x0, ttl 60, id 25028, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c4 0000 3c11 599d 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 9380 0600 ff07  .....o.l.H......
        0x0020:  06c0 a4a3 a2a0 0400 0000 2000 a41c 0000  ................
        0x0030:  2b1d 0000 a376 0000 4121 0000 f284 3193  +....v..A!....1.
        0x0040:  d81b f991 49d2 d56a 32e6 6c41 ffff 0207  ....I..j2.lA....
        0x0050:  d808 6a04 6c4d bc85 3842 839f            ..j.lM..8B..
19:41:59.278401 IP (tos 0x0, ttl 60, id 25028, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c4 0000 3c11 599d 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 9380 0600 ff07  .....o.l.H......
        0x0020:  06c0 a4a3 a2a0 0400 0000 2000 a41c 0000  ................
        0x0030:  2b1d 0000 a376 0000 4121 0000 f284 3193  +....v..A!....1.
        0x0040:  d81b f991 49d2 d56a 32e6 6c41 ffff 0207  ....I..j2.lA....
        0x0050:  d808 6a04 6c4d bc85 3842 839f            ..j.lM..8B..
19:41:59.278538 IP (tos 0x0, ttl 64, id 13686, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0xdc3e!] UDP, length 64
        0x0000:  4500 005c 3576 4000 4011 41eb 0afe 190c  E..\5v@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0700 0000 2000 6506 37fb  ............e.7.
        0x0030:  0e85 74b6 43f2 6abd 6d75 872d c8e1 15ea  ..t.C.j.mu.-....
        0x0040:  b266 1810 5e79 6e96 912a 6f3d ffff 0207  .f..^yn..*o=....
        0x0050:  0b06 682f fd2b 2bf5 131d fdef            ..h/.++.....
19:41:59.278544 IP (tos 0x0, ttl 64, id 13686, offset 0, flags [DF], proto UDP (17), length 92)
    seedhost.40556 > 10.10.148.45.asf-rmcp: [bad udp cksum 0xc389 -> 0xdc3e!] UDP, length 64
        0x0000:  4500 005c 3576 4000 4011 41eb 0afe 190c  E..\5v@.@.A.....
        0x0010:  0af9 942d 9e6c 026f 0048 c389 0600 ff07  ...-.l.o.H......
        0x0020:  06c0 9796 0b00 0700 0000 2000 6506 37fb  ............e.7.
        0x0030:  0e85 74b6 43f2 6abd 6d75 872d c8e1 15ea  ..t.C.j.mu.-....
        0x0040:  b266 1810 5e79 6e96 912a 6f3d ffff 0207  .f..^yn..*o=....
        0x0050:  0b06 682f fd2b 2bf5 131d fdef            ..h/.++.....
19:41:59.283382 IP (tos 0x0, ttl 60, id 25029, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c5 0000 3c11 599c 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 355b 0600 ff07  .....o.l.H5[....
        0x0020:  06c0 a4a3 a2a0 0500 0000 2000 2362 0000  ............#b..
        0x0030:  3200 0000 f770 0000 f827 0000 908f fc64  2....p...'.....d
        0x0040:  8a51 63cf c0ac 70a7 5616 71a6 ffff 0207  .Qc...p.V.q.....
        0x0050:  789f 7f8f aec3 3469 2e53 2913            x.....4i.S).
19:41:59.283382 IP (tos 0x0, ttl 60, id 25029, offset 0, flags [none], proto UDP (17), length 92)
    10.10.148.45.asf-rmcp > seedhost.40556: [udp sum ok] UDP, length 64
        0x0000:  4500 005c 61c5 0000 3c11 599c 0af9 942d  E..\a...<.Y....-
        0x0010:  0afe 190c 026f 9e6c 0048 355b 0600 ff07  .....o.l.H5[....
        0x0020:  06c0 a4a3 a2a0 0500 0000 2000 2362 0000  ............#b..
        0x0030:  3200 0000 f770 0000 f827 0000 908f fc64  2....p...'.....d
        0x0040:  8a51 63cf c0ac 70a7 5616 71a6 ffff 0207  .Qc...p.V.q.....
        0x0050:  789f 7f8f aec3 3469 2e53 2913            x.....4i.S).
^C
36 packets captured
36 packets received by filter
0 packets dropped by kernel
root@seedhost:~#

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