Unstable connection

Hi there !
I share ZeroTier between a few computers. Sometimes those computers share the same internal network, sometimes not. That’s one of the reason we use ZeroTier.

Sometimes, the connection becomes really unstable. I know it isn’t an issue in my physical network. How ? If I ping a machine on the network through its ZT IP address, I have many timeouts :

Request timeout for icmp_seq 3
64 bytes from 10.*.14: icmp_seq=3 ttl=64 time=1007.520 ms
64 bytes from 10.
.14: icmp_seq=4 ttl=64 time=8.545 ms
Request timeout for icmp_seq 6
Request timeout for icmp_seq 7
Request timeout for icmp_seq 8
Request timeout for icmp_seq 9
64 bytes from 10.
.14: icmp_seq=7 ttl=64 time=3159.897 ms
64 bytes from 10.
.14: icmp_seq=8 ttl=64 time=2158.794 ms
64 bytes from 10.
.*14: icmp_seq=9 ttl=64 time=1157.515 ms

If I ping the same machine through the local network everything works fine :

64 bytes from icmp_seq=0 ttl=64 time=2.206 ms
64 bytes from icmp_seq=1 ttl=64 time=1.730 ms
64 bytes from icmp_seq=2 ttl=64 time=84.514 ms
64 bytes from icmp_seq=3 ttl=64 time=1.744 ms
64 bytes from icmp_seq=4 ttl=64 time=2.249 ms
64 bytes from icmp_seq=5 ttl=64 time=1.113 ms
64 bytes from icmp_seq=6 ttl=64 time=71.381 ms
64 bytes from icmp_seq=7 ttl=64 time=5.673 ms
64 bytes from icmp_seq=8 ttl=64 time=2.375 ms
64 bytes from icmp_seq=9 ttl=64 time=25.289 ms

I have absolutely no clues why my ZT network is unstable. We have only 5 machines registered on the VPN (one of them is offline now), default configuration, no tweaks at all. The only thing is that I can’t manage the router of the network (that’s the main. reason I do use ZT) .

I have checked https://zerotier.atlassian.net/wiki/spaces/SD/pages/6815768/Router+Configuration+Tips and I don’t have double NAT.

I have this problem between each of my machines, not only two of them.

I have found some people with network issues but each time they had to restart their vpn or something like this. In my case, the network is just unstable, for a few seconds, at random times. Maybe it’s because of some congestion in ZT servers ? Maybe something else.

Any Idea ?

When you do zerotier-cli peers does it say DIRECT or RELAY? Does the ip address under path make sense?
3 second ping time means it’s either relaying through something very far away, or the CPU is too busy.

I would have thought it would be a NAT setting. Is your internet connection also stable? 3 seconds ping is of the charts high must say. I’m getting about 350ms on a few networks and also 60ms on a different network.

Thank you for your answers.

@zt-travis : Each connexion is direct except for one computer which is offline :

<ztaddr>   <ver>  <role> <lat> <link> <lastTX> <lastRX> <path>
3a46xxxxxx -      PLANET   156 DIRECT 4218     4064     185. xxxxxxxxxxxx/9993
5b90xxxxxx 1.4.6  LEAF       1 DIRECT 14227    14225    2a01: xxxxxxxxxxxx:fad2:93bb/9993
62f8xxxxxx -      PLANET   254 DIRECT 4218     3963     2001: xxxxxxxxxxxx:2::2/9993
6fb4xxxxxx 1.4.6  LEAF      -1 RELAY
778cxxxxxx -      PLANET   118 DIRECT 4218     4100     2605: xxxxxxxxxxxx:f2bc:a1f7:19/9993
8286xxxxxx 1.4.8  LEAF     154 DIRECT 9222     9069     34. xxxxxxxxxxxx/21000
992fcxxxxxx -      PLANET    18 DIRECT 4218     4199     195. xxxxxxxxxxxx/9993
a0efxxxxxx 1.4.6  LEAF      84 DIRECT 14227    14131    2a01: xxxxxxxxxxxx:f419:c04f:d6f/36869
fd3fxxxxxx 1.4.6  LEAF       2 DIRECT 4218     4216     2a01:xxxxxxxxxxxx:88c0:55f8/9993

@digixltd : The internet seems pretty stable and efficient (it’s a 1 Gbps connection) :

PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=121 time=9.56 ms
64 bytes from icmp_seq=2 ttl=121 time=9.32 ms
64 bytes from icmp_seq=3 ttl=121 time=9.89 ms
64 bytes from icmp_seq=4 ttl=121 time=9.63 ms
64 bytes from icmp_seq=5 ttl=121 time=9.75 ms
64 bytes from icmp_seq=6 ttl=121 time=9.15 ms
64 bytes from icmp_seq=7 ttl=121 time=9.92 ms