<html><head></head><body><div>Hello,</div><div>I have 6 Ubuntu 18.04 machines in a Tinc (1.35) network, where 3 are in Spain and 3 in UK.</div><div>One machine in each country is running Tinc, and as both ends are behind NAT, they both connect outward to an Upcloud VM.</div><div><br></div><div>The 4 non-tinc machines can Ping and SSH each other without issue, and so from that point of view, the Tinc VPN is working fine.</div><div>However, the 2 tinc machines can only ping and ssh each other across the vpn - they cannot reach any of the other 4 machines.</div><div>- they can of course ping and ssh the 2 machines on their own network.</div><div><br></div><div>I have found that I need to provide the 3 tinc machines with their own IPv4 network, as other approaches cause the networking on the Ubuntu machines to lock up.</div><div>IPv4 forwarding is turned on, and all 4 non-tinc machine have static routes configured, and the tinc machines have routes via the tun0 interfaces.</div><div><br></div><div>I have found i need TCPonly=yes to stop any Unknown messages.</div><div><br></div><div>With a tail on the log files and using to ping, I can see reports of messages going across the vpn.</div><div>But when trying ping on the tinc machines, the log message is slightly different between the tinc and non-tinc machines - so I'm not sure the ICMP message is actually getting into the tun0 interface.</div><div><br></div><div>As the config is very symmetrical, I enclose here the config of one side.</div><div><br></div><div>###TINC.CONF</div><div><span><div>ConnectTo=upcloud</div><div>Name = zotacubuntu1</div><div>AddressFamily = ipv4</div><div>Device = /dev/net/tun</div><div>LocalDiscovery = yes</div><div>TCPOnly = yes</div></span><br></div><div>###TINC-UP</div><div><span><div>ip link set $INTERFACE up</div><div>ip addr add 192.168.60.20/24 dev $INTERFACE</div><div> <span>ip route add 192.168.4.0/24 dev $INTERFACE</span><br></div><div><br></div></span></div><div>###hosts/zotacubuntu1</div><div><span><div>Address =UK.dyndns.org</div><div>Port = 655</div><div>Subnet = 192.168.60.20/32<br></div><div>Subnet = 192.168.14.0/24</div></span><br></div><div>###route -n</div><div><span><div>Kernel IP routing table</div><div>Destination Gateway Genmask Flags Metric Ref Use Iface</div><div>0.0.0.0 192.168.14.1 0.0.0.0 UG 0 0 0 wlp2s0</div><div>169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlp2s0</div><div>192.168.4.0 0.0.0.0 255.255.255.0 U 0 0 0 tun0</div><div>192.168.14.0 0.0.0.0 255.255.255.0 U 0 0 0 wlp2s0</div><div>192.168.60.0 0.0.0.0 255.255.255.0 U 0 0 0 tun0</div><div><br></div></span></div><div><br></div><div>I've run out of ideas as to why.<br>Can anyone suggest reason and/or what else I can try?</div><div><br></div><div>Thanks</div><div>John</div><div><br></div><div class="ydp821e1520yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"></div></body></html>