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check_1_1_sp_comms [2021/04/08 16:53] – walkeradmincheck_1_1_sp_comms [2021/04/08 17:03] – [Introduction] walkeradmin
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 15778 for stat Mux 15778 for stat Mux
 +</file>
 +\\ 
 +We can use tcpdump to monitor the traffic between the Muxes by specifying the relevant port.
 +\\ 
 +    tcpdump -i mngt port 15778 -Q out
 +\\ 
 +This will show Stat Mux traffic (as in the stat mux control messages).
 +\\ 
 +\\ 
 +The active Mux will show something like below:
 +<file>
 +tcpdump -i eth0 port 15778 -Q out
 +
 +tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 +listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
 +15:49:22.309719 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:22.851978 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:23.394021 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:23.936007 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:24.478037 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:25.019993 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:25.562039 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:26.104193 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:26.646276 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +15:49:27.188263 IP sp01.15778 > 235.2.127.254.15778: UDP, length 61
 +</file>
 +\\ 
 +Where as the inactive mux will have no tcpdump output
 +\\ 
 +<file>
 +tcpdump -i eth0 port 15778 -Q out
 +
 +tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 +listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
 +</file>
 +\\ 
 +If we look at the Mux Comms on 15771 then we see activity from BOTH Muxes:
 +<file>
 +On the Main Mux
 +
 +tcpdump -i eth0 port 15771 -Q out
 +
 +tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 +listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
 +15:58:10.290160 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:10.790638 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:11.290752 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:11.791356 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:12.291375 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:12.791417 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:13.291816 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:13.792613 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:14.293486 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +15:58:14.793887 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +</file>
 +\\ 
 +<file>
 +On the Backup Mux
 +
 +tcpdump -i eth0 port 15771 -Q out
 +
 +tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 +listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
 +15:58:10.255915 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:10.756223 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:11.256603 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:11.756856 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:12.257007 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:12.757740 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:13.258254 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:13.758822 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:14.259383 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +15:58:14.760368 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +</file>
 +\\ 
 +Unfortunately both outputs look the same, but if we add -A to the command line, so:
 +\\ 
 +\\ 
 +tcpdump -i eth0 port 15771 -Q out -A
 +\\ 
 +\\ 
 +We see the following:
 +\\ 
 +<file>
 +From the MAIN Mux
 +
 +tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 +listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
 +16:02:20.064957 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +E....6@.@..W........=.=....]{
 +    "uid": "SP01",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895607872,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": true,
 +        "transmitting": true
 +    },
 +    "cc": 134
 +}
 +
 +16:02:20.565987 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +E....]@.@..0........=.=....]{
 +    "uid": "SP01",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895607872,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": true,
 +        "transmitting": true
 +    },
 +    "cc": 135
 +}
 +
 +16:02:21.066788 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +E... .@.@...........=.=....]{
 +    "uid": "SP01",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895607872,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": true,
 +        "transmitting": true
 +    },
 +    "cc": 136
 +}
 +
 +16:02:21.566860 IP sp01.15771 > 235.2.127.254.15771: UDP, length 207
 +E...!.@.@...........=.=....]{
 +    "uid": "SP01",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895607872,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": true,
 +        "transmitting": true
 +    },
 +    "cc": 137
 +}
 +</file>
 +\\ 
 +<file>
 +From the BACKUP Mux
 +
 +tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 +listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
 +16:02:20.027155 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +E...j"@.@..h........=.=....`{
 +    "uid": "SP02",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895627134,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": false,
 +        "transmitting": false
 +    },
 +    "cc": 135
 +}
 +
 +16:02:20.527548 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +E...j.@.@...........=.=....`{
 +    "uid": "SP02",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895627134,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": false,
 +        "transmitting": false
 +    },
 +    "cc": 136
 +}
 +
 +16:02:21.028483 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +E...k.@.@...........=.=....`{
 +    "uid": "SP02",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895627134,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": false,
 +        "transmitting": false
 +    },
 +    "cc": 137
 +}
 +
 +16:02:21.528890 IP sp02.15771 > 235.2.127.254.15771: UDP, length 209
 +E...mZ@.@..0........=.=....`{
 +    "uid": "SP02",
 +    "groupName": "mux_mux_52_1_1",
 +    "startTime": 1617895627134,
 +    "removed": false,
 +    "privateData": {
 +        "oldest": false,
 +        "transmitting": false
 +    },
 +    "cc": 138
 +}
 </file> </file>
check_1_1_sp_comms.txt · Last modified: 2023/03/09 22:35 by 127.0.0.1