How to close stale lightning channels with c-lightning I was running a lightning node using c-lightning about 9 months ago. Unfortunately the server was shutdown while a few channels were open.

I have restarted the server and updated c-lightning to the latest version (0.6.3). After restarting both bitcoind and lightningd I am left with the 2 stale channels.

zap:~# lightning/cli/lightning-cli listpeers
{
  "peers": [
    {
      "connected": false, 
      "channels": [
        {
          "state": "CHANNELD_NORMAL",
          ...
          "status": [
            "CHANNELD_NORMAL:Attempting to reconnect"
          ],
          ...
        }
      ]
    }, 
    {
      "connected": false, 
      "channels": [
        {
          "state": "CHANNELD_NORMAL",
          ...
          "status": [
            "CHANNELD_NORMAL:Attempting to reconnect"
          ], 
          ...
        }
      ]
    }, 
  ]
}


I am unable to connect back to these pairs using lightning/cli/lightning-cli connect x, when I try I get timeout or route errors. (EDIT: which means the other nodes are now down).
The problem seems that the other nodes are also offline which is why you can't connect to them.

Luckily you don't have to be connected  as you can do a force close by publishing your channel state to the Bitcoin network (the disadvantage is that you have to wait for the timelock until you can spend your outputs) 

Just try lightning-cli close ENTER-CHANNEL-ID-HERE in case you are not connected your node should perform a force close