re: RE: Vague JetDirect Problem

[MHurlburt () nea org]

Michael are you saying that the JetDirect interfaces are forcing bidirectional 
communication to <all three> interfaces in said NT print host over TCP? And 
subsequently choosing which one to use on a round-robin fashion?

I could see this if the DLC protocol was enabled on the NT host to enable 
communications to some *old* HP JetDirect interfaces only capable of utilizing 
DLC, but w/ IP?  It was my understanding that the Intels have a pulsing 
interval (I assume RARP's) in which the backup nics poll the 'others,' but I 
only thought this was for their failover capabilities and not for load 
balancing.

Also, shall we assume then that load balancing does not truly scale with the 
Intels?  Ie. if0 + if1 +if2 (Full Dup) does not necessarily = 300MB/Full 
Duplex as is suggested?

Could you elaborate on this or give some pointers on what / whom you 
researched this issue with?

Thanks,

Mike 

"Michael A. Traffanstead" <traff () txdigital com> Wrote:
| 
| 
| Recently we purchased an HP 4050TN with a Jet Direct card, 
| everyone was
| fat and happy for a while.  Then we took down our NT print 
| server and
| installed two new intel pro 100+ nic's.  We setup these 
| two cards to do
| adaptive load balancing with the existing pro 100+ ( very 
| slick and
| easy to setup btw ).  After that, our 4050TN experienced 
| exactly the
| same problems you are describing.  If we unplugged any two 
| of the three
| cards the problem went away.  After doing some research I 
| discovered
| that if JetDirect discovers it can communicate directly 
| with the printer
| using MAC addresses, it will ( even if you've specifically 
| specified
| TCP/IP in the settings ).  This was causing problem b/c 
| Intel's
| adaptive load balancing only receives on one of the cards. 
|  So data was
| being sent out from one of three cards and the JetDirect 
| card in the
| printer would try to communicate directly with that 
| card... which will
| not work (~2/3 of the time at least).
| 
| Hopefully this might help you identify your problem.
| 
| traff
| 
| -----Original Message-----
| From: owner-firewall-wizards () lists nfr net
| [mailto:owner-firewall-wizards () lists nfr net]On Behalf Of 
| wpl1 () jps net
| Sent: Saturday, September 11, 1999 11:04 AM
| To: firewall-wizards () nfr net
| Subject: Vague JetDirect Problem
| 
| 
| The subject reads "vague" because I'm not sure this is 
| really a firewall
| issue--but it could be.  We have installed a single 
| JetDirect device in our
| building.  The network sees the device and workstations 
| may be configured to
| recognize it.  Our building, in which a couple dozen 
| workstations connect to
| one of two daisy-chained hubs, connects to via fiber to 
| the MDF in another
| building where several dozen workstations are more 
| efficiently connecting to
| switches.  The JetDirect is connected to one of those two 
| chained hubs in
| our building.
| 
| The firewall is a Cisco PIX sitting off of one of the 
| aforementioned
| switches at the remote building.  There are three routers 
| in the picture,
| all located in the remote building.  One routes data from 
| our building
| across a WAN to yet another site; one routes across still 
| another WAN; the
| third is outside the firewall pointing to our ISP.
| 
| The JetDirect's configured gateway is the internal IP of 
| the firewall.
| 
| Now, folks at the remote building (site of the MDF, et 
| al.) can print to our
| device.  We can print from our building to devices at the 
| remote building.
| But we can't print to our device.  (The printer never 
| produces the job which
| remains as a pending job according to the printer's 
| status.)  The network
| print server is a host connected to the switches mentioned 
| above.  Is the
| gateway configuration--which is the same for all 
| successfully operating
| JetDirects on the network--feeding the data by default to 
| the PIX?  Is the
| PIX possibly trashing the data?
| 
| The network is NT; workstations run 98.
| 
| Any assistance will be appreciated.  A simple reply of 
| "Huh?" will be
| understood, as well.  Apologies in advance for my not 
| having sufficient
| technical prowess to clearly describe this problem.
| 
| Dean C. Rowan
| Whittier Public Library
| 
| 


This email, it's files or previous e-mail attached to it, may contain 
confidential information being legally privileged.  Please disregard the 
contents if you are not the intended recepient.


******************************************************************
Only the individual sender is responsible for the content of this
message, and the message does not necessarily reflect the position
or policy of the National Education Association or its affiliates.