We have reports from 2 clients about not being able to connect to MSSQL11, we are not seeing issues for everyone on this, however we just saw an error that there is a network issue with the SQL server in logs, it is failing to read/write some network commands properly, we are checking this and it may require a service or server restart.
It looks like it is going to take a reboot to resolve the issue with the network communications not working now for some users.
the reboot happened about 10 minutes ago, and DBs are launching now.