Tuesday, 29 July 2014

Re: SLP (Service Location Protocol)

Hi there,

I played with SLP 10+ years ago and thought it was pretty much dead, but it seems it's still being used to advertize printers -- wow!

On Wed, Jul 23, 2014 at 4:59 PM, Till Kamppeter <till.kamppeter@gmail.com> wrote:
I want to let cups-browsed do this automatically, so that I can set up
driver-less print queues for printers with known languages (PDF,
PostScript, PCL, ...) but without polling the printer directly to not
wake up the printer from power save mode.

I guess waking up the printer or not is going to be vendor specific, depending on the implementation of the network/SLP stack on the printer.
What I would like to know is:

1. How do I scan the network for SLP services without knowing service
names and types and without knowing which hosts in the network provide
services or are SLP directory agents?

There are specific queries to search services by service type or to search for servers/agents. It used to be possible to list all services on a network, but I think nowadays you have to list all servers and then list all service types (findsrvtypes) and then all instances of this type (findsrvs <type>).
2. In a typical SoHo network, are there SLP services or directory
agents? Are the usual SoHo routers directory agents? Or do we need to
make it part of the Ubuntu standard installation to run an SLP server
daemon to be able to make use of SLP?

I dont think SLP is common in routers and I wouldn't think we'd want to install more central agents/servers by default when we dont know the general network topology. The trend seems to be for individual services to advertise themselves over mDNS/Bonjour rather than anything centralized and/or SLP.
3. How can I test my environment with command line tools?

slptool is your new friend!
Loïc Minier