# sshd ``` error: no more sessions ``` sshd_config: ``` MaxSessions 20 ``` ## config ``` # global Host * User root ForwardAgent yes ControlMaster auto ControlPath ~/.ssh/control-%r@%h:%p ControlPersist 1h ``` ## escape to controlconsole `In the default setup the basic escape character is ~ (you can specify this by using EscapeChar in your configuration)` `~C` ``` ~. Disconnect. ~^Z Background ssh. ~# List forwarded connections. ~& Background ssh at logout when waiting for forwarded connection / X11 sessions to terminate. ~? Display a list of escape characters. ~B Send a BREAK to the remote system (only useful if the peer supports it). ~C Open command line. Currently this allows the addition of port forwardings using the -L, -R and -D options (see above). It also allows the cancellation of existing port-forwardings with -KL[bind_address:]port for local, -KR[bind_address:] port for remote and -KD[bind_address:]port for dynamic port-forwardings. !command allows the user to execute a local command if the PermitLocalCommand option is enabled in ssh_config(5). Basic help is available, using the -h option. ~R Request rekeying of the connection (only useful if the peer supports it). ~V Decrease the verbosity (LogLevel) when errors are being written to stderr. ~v Increase the verbosity (LogLevel) when errors are being written to stderr. ```