Irssi

Connecting to ZNC

SSL

/network add freenode 
/server add -net freenode -auto -ssl my.bouncer.net 6697 username/freenode:password
/save
/connect freenode

Non SSL

/network add freenode 
/server add -net freenode -auto my.bouncer.net 6667 username/freenode:password
/save
/connect freenode

Notes

Irssi does not send unknown commands to irc server or znc so you will get an unknown command error when you try to use the /znc alias. If you want /znc to work you need to enter /alias znc msg *status.

Or, you can download dispatch.pl placing the script in ~/.irssi/scripts/autorun and typing /script load autorun/dispatch. You will only need to enter the command once as irssi will automatically load the script next time irssi is started.

Irssi by default will create new channel windows each time znc reconnects to the irc network. After you join all your channels you can enter /layout save to have irssi reuse channel windows instead of creating new windows.