Problem monitoring the gateway of a Viasat satellite connection

Started by vpx, July 05, 2023, 02:23:34 PM

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Hi there,

I have a problem with the monitoring of a satellite connection. It is a Viasat SurfBeam 2 modem.

The WAN4 interface gets its IP from a DHCP server of the SAT modem/router. Everything is working but the gateway is always shown as offline even when you see the RTT in the gateway overview.

For test purposes I already unchecked the options "Block private networks" and "Block bogon networks" in the WAN4 interface without an effect.

As you see all other WANs are monitored fine so I guess it's a weird problem in relation to the satellite modem.

Here is the packet capture of a ping to the DNS server which I use as the monitor IP (I also already tried the CloudFlare DNS 1.1.1.1, same result).


Interface Timestamp SRC DST output
WAN4
ix3 2023-07-05
12:43:26.873269 3c:ec:xx:xx:xx:xx 00:a0:xx:xx:xx:xx ethertype IPv4 (0x0800), length 42: (tos 0x0, ttl 64, id 7282, offset 0, flags [none], proto ICMP (1), length 28)
10.80.xxx.xx > 70.41.xx.x: ICMP echo request, id 6505, seq 481, length 8
WAN4
ix3 2023-07-05
12:43:27.453004 00:a0:xx:xx:xx:xx 3c:ec:xx:xx:xx:xx ethertype IPv4 (0x0800), length 60: (tos 0x0, ttl 55, id 18232, offset 0, flags [none], proto ICMP (1), length 28)
70.41.xxx.x > 10.80.xxx.xx: ICMP echo reply, id 6505, seq 481, length 8
WAN4
ix3 2023-07-05
12:43:31.980280 3c:ec:xx:xx:xx:xx 00:a0:xx:xx:xx:xx ethertype IPv4 (0x0800), length 42: (tos 0x0, ttl 64, id 63227, offset 0, flags [none], proto ICMP (1), length 28)
    10.80.xxx.xx > 70.41.xx.x: ICMP echo request, id 6505, seq 482, length 8
WAN4
ix3 2023-07-05
12:43:32.575468 00:a0:xx:xx:xx:xx 3c:ec:xx:xx:xx:xx ethertype IPv4 (0x0800), length 60: (tos 0x0, ttl 55, id 21553, offset 0, flags [none], proto ICMP (1), length 28)
70.41.xx.x > 10.80.xxx.xx: ICMP echo reply, id 6505, seq 482, length 8
WAN4
ix3 2023-07-05
12:43:36.982371 3c:ec:xx:xx:xx:xx 00:a0:xx:xx:xx:xx ethertype IPv4 (0x0800), length 42: (tos 0x0, ttl 64, id 43380, offset 0, flags [none], proto ICMP (1), length 28)
10.80.xxx.xx > 70.41.xx.x: ICMP echo request, id 6505, seq 483, length 8
WAN4
ix3 2023-07-05
12:43:37.571897 00:a0:xx:xx:xx:xx 3c:ec:xx:xx:xx:xx ethertype IPv4 (0x0800), length 60: (tos 0x0, ttl 55, id 24420, offset 0, flags [none], proto ICMP (1), length 28)
70.41.xx.x > 10.80.xxx.xx: ICMP echo reply, id 6505, seq 483, length 8


While writing I found the problem myself, I just had to increase the "Latency thresholds" from the default 200/500 range to 700/900 because the RTT of a satellite connection is so high. Maybe It helps somebody in the future. :D

Successful rubber duck debugging! 👍
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