Client and server network printing protocols

Microsoft print servers support different protocols to allow clients to submit print jobs over the network. The most common are IPP (Internet Printing Protocol), SMB (Server Message Block) and LPD (Line Printer Daemon). The pros and cons of each protocol when deployed behind an NLB appliance are described in the following table.

Protocol Pros Cons

IPP - (Internet Printing Protocol)

  • Requires only one listener port configured on the NLB.
  • Supports encryption using IPP over SSL.
  • Strong integration between NLB technology and web based protocols.
  • Requires that the IPP client is installed/enabled on every workstation.

SMB - (Server Message Block)

  • Requires no client workstation modification.
  • Can be deployed using OS standard tooling such as Group Policy Object (GPO).
  • Requires a large number of listener ports configured on the NLB. This is due to SMB generating multiple Remote Procedure Calls (RPC) from the client to the server side spooler on random destination ports.
    It is possible to force all RPC’s to initiate using named pipes instead of TCP/IP by using the DisableRpcTcp flag. Setting this flag reduces the number of listener ports.
  • Requires the addition/modification of certain registry keys on each print server.

LPD - (Line Printer Daemon)

  • Requires only one listener port to be configured on the NLB.
  • Works across non-trusted domains.
  • Can be used to deliver print jobs from non-Windows clients.
  • Requires creation of a local print queue with an LPR port on every workstation.