I have only one route in the ZT panel: 10.x.y.0/21(LAN) and it’s not segmented anywhere at the moment (all peers are just endpoints).
However I have dusted off another endpoint (my RaspberryPi 4), and found out that I can connect it to and from my PC (on the same LAN). Also another Windows endpoint (external to my LAN) started to work from my PC.
I narrowed it down to just one instance not working - an OpenVZ VPS, which coincidentally I’ve been using as an internal DNS server. The connections stoppped working there and there’s a weird symptom when pinging any ZT host from there:
# ping 10.x.y.2
PING 10.x.y.2 (10.x.y.2) 56(84) bytes of data.
From 10.x.y.1 icmp_seq=2 Destination Host Unreachable
From 10.x.y.1 icmp_seq=3 Destination Host Unreachable
From 10.x.y.1 icmp_seq=4 Destination Host Unreachable
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
^C
--- 10.x.y.2 ping statistics ---
12 packets transmitted, 0 received, +3 errors, 100% packet loss, time 38026ms
pipe 3
I tried downgrading the zerotier version there to no avail. I just may have to ditch that VPS…