check_1_1_sp_comms
Check 1+1 SP Comms
Apr 2021
Introduction
The 1+1 SPs communicate with each other over the Management network using various ports, these are:
15771 for Mux comms 15772 for Simulcrypt 15778 for stat Mux
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:
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
Where as the inactive mux will have no tcpdump output
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
If we look at the Mux Comms on 15771 then we see activity from BOTH Muxes:
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
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
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:
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
}
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
}
check_1_1_sp_comms.txt · Last modified: 2023/03/09 22:35 by 127.0.0.1