Bug #276

JetDirect protocol does not seem to be working between networks

Added by Jim Gettys on Sep 22, 2011. Updated on Apr 20, 2012.
Closed High Jim Gettys


There is some sort of discovery protocol that JetDirect uses (or at least the Linux printing system uses to discover printers on the net).

This does not seem to be working; whether it can/should work in a routed world is less clear.

I don’t see this as highly important right now, but maybe someday…


Updated by Jim Gettys on Sep 22, 2011.
Seems likely this is some sort of SNMP broadcast protocol being used to discover the printers on the network, according to CUPS documentation.


Updated by Dave Täht on Sep 22, 2011.
Just to verify, the jetdirect protocol itself, works across the networks, it’s just discovery that is borked?

I note that guests should NOT be able to access printer resources on the secure lan.

As for addressing this:

samba can run on the router, providing a central rendezvous point for printer information.
mdns - if implemented, and I thought it was in cups LONG ago, should also be able to do the trick,
but this would be a good test.

Updated by Jim Gettys on Sep 22, 2011.
It’s the discovery of the printer (via snmp broadcast) that seems to be the problem here, if I read my tea leaves right. The cups configuration stuff on Linux (and maybe mac) seems to use it to find printers when configuring a new printer.

To confirm this theorya, we need to do a little bit of wire sniffing.

This begs the question of how common this use of snmp broadcast is in other applications and operating systems.

Updated by Jim Gettys on Nov 18, 2011.
I need to sniff to see what is happening when on the same segment so we can figure out what the next step should be. See if SNMP theory of jg is correct….
Updated by Dave Täht on Apr 20, 2012.

This is a static export of the original bufferbloat.net issue database. As such, no further commenting is possible; the information is solely here for archival purposes.
RSS feed

Recent Updates

Oct 20, 2023 Wiki page
What Can I Do About Bufferbloat?
Dec 3, 2022 Wiki page
Codel Wiki
Jun 11, 2022 Wiki page
More about Bufferbloat
Jun 11, 2022 Wiki page
Tests for Bufferbloat
Dec 7, 2021 Wiki page
Getting SQM Running Right

Find us elsewhere

Bufferbloat Mailing Lists
#bufferbloat on Twitter
Google+ group
Archived Bufferbloat pages from the Wayback Machine


Comcast Research Innovation Fund
Nlnet Foundation
Shuttleworth Foundation

Bufferbloat Related Projects

OpenWrt Project
Congestion Control Blog
Flent Network Test Suite
The Cake shaper
CeroWrt (where it all started)

Network Performance Related Resources

Jim Gettys' Blog - The chairman of the Fjord
Toke's Blog - Karlstad University's work on bloat
Voip Users Conference - Weekly Videoconference mostly about voip
Candelatech - A wifi testing company that "gets it".