I've saved this script at /usr/local/bin/moshiĪnd as you can see the script expects a rudimentary mosh config file at ~/.ssh/mosh_config. Since there could easily be many ports with many hosts I've made a very simple script to handle the port config for the first connection. Since you've made it this far hopefully this is working for you too now. Thus for each additional connection you'll need to increment your port number by 2. This is because mosh uses the requested port for one direction of the communication, and the port+1 for the return communication. With this config you can establish up to 5 total connections to the each guest. With all the relevant ports being forwarded you can now set up your SSH config in ~/.ssh/configĪnd finally you should be able to establish a mosh connection with a defined port: Iptables -A PREROUTING -i eth0 -p udp -dport 60020:60029 -j DNAT -to-destination 10.1.1.2 Iptables -A PREROUTING -i eth0 -p udp -dport 60010:60019 -j DNAT -to-destination 10.1.1.1 This will quickly overlap between host and guests. It seems that by default mosh will start listening at the low end of the ports, so each LXC container will listen on port 60001 by default first. Iptables -A PREROUTING -i eth0 -p tcp -dport 22002 -j DNAT -to-destination 10.1.1.2:22Īnd finally port forwarding for mosh. Iptables -A PREROUTING -i eth0 -p tcp -dport 22001 -j DNAT -to-destination 10.1.1.1:22 Then you need to set up port forwarding for ssh: Iptables -A POSTROUTING -o eth0 -s 10.1.1.0/24 -j MASQUERADE Prox圜ommand ssh lxc-master-1 /bin/nc -q 8 -w 3 lxc-guest-1 22įor mosh you need to get far more involved, setting up port forwarding through the NAT and finally having custom command lines to connect.įirst, to get this NAT working the standard easiest approach is to: My preferred approach is to make use of the Prox圜ommand through the NAT'ing master, however this doesn't work with mosh:

With SSH there are a couple of ways to handle this scenario. This requires iptables rules and some client-side magic. In this case you wouldn't normally be able to establish a mosh connection to either of the guest servers, however with some ugly setup it can be done. Frequently these LXC's are behind a NAT like this: I have LXC containers running on bare metal hardware. However my motivation for this post relates more to the need to configure a port for a particular host, which leads me to the NAT related point. For example to create shortcut entries for hosts, or to handle some sort of Prox圜ommand, etc. Regarding point three, I find myself wanting a configuration file much like SSH for various reasons. I expect this too should be an easy win and I hope it will be coming sooner than later. The lack of IPv6 support is frustrating since there is the lack of SSH agent forwarding and the inability for mosh to easily traverse NAT's.

There appear to be enough people feeling the pain so I suspect this will be resolved soon. The first point about SSH agent forwarding I'm hoping will just need some patience.

No configuration file similar to SSH's ssh_config or ~/.ssh/config.

This is a pretty big deal and a source of much frustration. In particular the following points need patience or workarounds: There are a few aspects of it that are not the most convenient, but these are balanced out by other features. I've been using mosh for a few days now and find it very promising.

Mosh port forwarding