9416f643_Network_Security__Description_and_exceptions
Printing Stanford campus network. [Description and exceptions] 
Only the lpd (port 515), ipp (port 631), or HP jetdirect (port 9100) printer connection protocols are allowed. If you need to send print jobs to an Earth Sciences printer from home or while traveling with a portable computer, install and use the Stanford public VPN client to get through the firewall.
Network Security
Description and exceptions