I also see this kind of nonsense:
64 bytes from a.b.c.d: icmp_seq=0 ttl=126 time=38.658 ms
64 bytes from a.b.c.d: icmp_seq=1 ttl=126 time=37.179 ms
64 bytes from a.b.c.d: icmp_seq=2 ttl=126 time=36.111 ms
64 bytes from a.b.c.d: icmp_seq=3 ttl=126 time=35.122 ms
64 bytes from a.b.c.d: icmp_seq=4 ttl=126 time=34.282 ms
64 bytes from a.b.c.d: icmp_seq=5 ttl=126 time=33.197 ms
64 bytes from a.b.c.d: icmp_seq=6 ttl=126 time=32.178 ms
64 bytes from a.b.c.d: icmp_seq=7 ttl=126 time=32.130 ms
64 bytes from a.b.c.d: icmp_seq=8 ttl=126 time=41.201 ms
64 bytes from a.b.c.d: icmp_seq=9 ttl=126 time=40.100 ms
64 bytes from a.b.c.d: icmp_seq=10 ttl=126 time=39.142 ms
64 bytes from a.b.c.d: icmp_seq=11 ttl=126 time=38.003 ms
64 bytes from a.b.c.d: icmp_seq=12 ttl=126 time=38.140 ms
64 bytes from a.b.c.d: icmp_seq=13 ttl=126 time=37.151 ms
64 bytes from a.b.c.d: icmp_seq=14 ttl=126 time=36.157 ms
64 bytes from a.b.c.d: icmp_seq=15 ttl=126 time=35.112 ms
64 bytes from a.b.c.d: icmp_seq=16 ttl=126 time=34.137 ms
64 bytes from a.b.c.d: icmp_seq=17 ttl=126 time=35.106 ms
64 bytes from a.b.c.d: icmp_seq=18 ttl=126 time=34.139 ms
64 bytes from a.b.c.d: icmp_seq=19 ttl=126 time=43.137 ms
64 bytes from a.b.c.d: icmp_seq=20 ttl=126 time=32.192 ms
64 bytes from a.b.c.d: icmp_seq=21 ttl=126 time=31.134 ms
64 bytes from a.b.c.d: icmp_seq=22 ttl=126 time=40.005 ms
I didn't copy-paste enough pings, but yes, there are also random spikes.
Cycling between 31 and 40 with many consecutive pings being almost exactly 1 ms off from the last -- suspicious... Just for fun, I like to speculate that the routing engine, or at least the part that's handling ICMP replies, has some sort of a poll-driven mechanism (as opposed to interrupt-driven) that checks for incoming packets every so often but only if it's not busy with something else.
------------------------------
Nikolay Semov
------------------------------
Original Message:
Sent: 04-12-2024 04:28
From: sva
Subject: Ping from SRX3xx
Greetings. We have SRX345 on which I observe the following: when I ping some IP address from it, some replies have high latency:
64 bytes from a.b.c.d: icmp_seq=48 ttl=55 time=36.534 ms
64 bytes from a.b.c.d: icmp_seq=49 ttl=55 time=37.352 ms
64 bytes from a.b.c.d: icmp_seq=50 ttl=55 time=36.389 ms
64 bytes from a.b.c.d: icmp_seq=51 ttl=55 time=36.381 ms
64 bytes from a.b.c.d: icmp_seq=52 ttl=55 time=36.242 ms
64 bytes from a.b.c.d: icmp_seq=53 ttl=55 time=38.165 ms
64 bytes from a.b.c.d: icmp_seq=54 ttl=55 time=173.321 ms
64 bytes from a.b.c.d: icmp_seq=55 ttl=55 time=420.768 ms
64 bytes from a.b.c.d: icmp_seq=56 ttl=55 time=36.484 ms
64 bytes from a.b.c.d: icmp_seq=57 ttl=55 time=36.370 ms
64 bytes from a.b.c.d: icmp_seq=58 ttl=55 time=505.974 ms
64 bytes from a.b.c.d: icmp_seq=59 ttl=55 time=49.361 ms
64 bytes from a.b.c.d: icmp_seq=60 ttl=55 time=54.231 ms
64 bytes from a.b.c.d: icmp_seq=61 ttl=55 time=67.610 ms
64 bytes from a.b.c.d: icmp_seq=62 ttl=55 time=42.658 ms
64 bytes from a.b.c.d: icmp_seq=63 ttl=55 time=39.336 ms
64 bytes from a.b.c.d: icmp_seq=64 ttl=55 time=36.727 ms
64 bytes from a.b.c.d: icmp_seq=65 ttl=55 time=36.971 ms
64 bytes from a.b.c.d: icmp_seq=66 ttl=55 time=37.266 ms
64 bytes from a.b.c.d: icmp_seq=67 ttl=55 time=36.591 ms
64 bytes from a.b.c.d: icmp_seq=68 ttl=55 time=136.710 ms
64 bytes from a.b.c.d: icmp_seq=69 ttl=55 time=36.456 ms
64 bytes from a.b.c.d: icmp_seq=70 ttl=55 time=37.808 ms
64 bytes from a.b.c.d: icmp_seq=71 ttl=55 time=37.275 ms
64 bytes from a.b.c.d: icmp_seq=72 ttl=55 time=36.530 ms
64 bytes from a.b.c.d: icmp_seq=73 ttl=55 time=38.975 ms
64 bytes from a.b.c.d: icmp_seq=74 ttl=55 time=38.718 ms
64 bytes from a.b.c.d: icmp_seq=75 ttl=55 time=41.931 ms
64 bytes from a.b.c.d: icmp_seq=76 ttl=55 time=39.002 ms
64 bytes from a.b.c.d: icmp_seq=77 ttl=55 time=38.702 ms
64 bytes from a.b.c.d: icmp_seq=78 ttl=55 time=37.269 ms
64 bytes from a.b.c.d: icmp_seq=79 ttl=55 time=37.984 ms
64 bytes from a.b.c.d: icmp_seq=80 ttl=55 time=38.999 ms
^C
--- a.b.c.d ping statistics ---
81 packets transmitted, 81 packets received, 0% packet loss
round-trip min/avg/max/stddev = 36.187/52.241/505.974/68.458 ms
But when I ping same IP from machines that behind this SRX, everything is fine:
64 bytes from a.b.c.d: icmp_seq=60 ttl=55 time=35.1 ms
64 bytes from a.b.c.d: icmp_seq=61 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=62 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=63 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=64 ttl=55 time=35.4 ms
64 bytes from a.b.c.d: icmp_seq=65 ttl=55 time=35.1 ms
64 bytes from a.b.c.d: icmp_seq=66 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=67 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=68 ttl=55 time=35.1 ms
64 bytes from a.b.c.d: icmp_seq=69 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=70 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=71 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=72 ttl=55 time=35.4 ms
64 bytes from a.b.c.d: icmp_seq=73 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=74 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=75 ttl=55 time=35.4 ms
64 bytes from a.b.c.d: icmp_seq=76 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=77 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=78 ttl=55 time=35.1 ms
64 bytes from a.b.c.d: icmp_seq=79 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=80 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=81 ttl=55 time=35.1 ms
64 bytes from a.b.c.d: icmp_seq=82 ttl=55 time=35.3 ms
64 bytes from a.b.c.d: icmp_seq=83 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=84 ttl=55 time=35.2 ms
64 bytes from a.b.c.d: icmp_seq=85 ttl=55 time=35.5 ms
^C
--- a.b.c.d ping statistics ---
85 packets transmitted, 85 received, 0% packet loss, time 84103ms
rtt min/avg/max/mdev = 34.979/35.241/35.562/0.202 ms
Is this normal? Does it have something to do with the priority of the SRX'es CLI process?