[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference netcad::hub_mgnt

Title:	DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:	Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:	NETCAD::COLELLADT

Created:	Wed Nov 13 1991
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	4455
Total number of notes:	16761

3702.0. "MOPRC packets causing PCs to hang" by GIDDAY::DANIEL () Thu Jul 11 1996 10:38

	A customer has reported that his PC running PW V5.1 configured for 
	decnet is constantly (about every 523 seconds!)sending out SYSID MOP 
	Remote console packets (60-02) with Destination Multicast address of 
	ab-00-00-02-00-00.

	1. What is the necessity for the PC to send this out unsolicited?
	2. Cust claims that this causes hang of other PC's. What could be the
	   the reason for the hang?
	
	I read the following article relating to MOP802 packets & Rev 2.0.0 of
	DR90TS, 90FS, & 900TM causing problem, but this is ethernet type packet.
	Is this problem also seen on V3.0.0 MOP packets?

	I have been able to check the MOP SYSID packets on CSC networkk from 
	a no. of PCs. I shall eliminate the possibility of V2.0 Rev on 
	Repeaters

	Daniel.
------------------------------------------------------------------------------
{Elev} Bad MOPRC packets from DECHub modules, invalid DSAP/SSAP fields


SYMPTOM:

Customer is seeing invalid 802 MOPRC SYSID frames on the network.   The
customer has some IBM PC's on the network that hang or disconnect when they
receive these invalid 802 frames with the DSAP and SSAP fields of zero.


ANALYSIS:

Problem in firmware seems to occur on the following DECHub modules:

DECrepeater 90 TS (the UTP repeater) version 2.0.0, and
DECrepeater 90 FS (the fiber repeater) version 2.0.0, and
DECrepeater 900TM (the 16 port UTP repeater) version 2.0.0

T.R Title User Personal
Name Date Lines

3702.1 TUBORG::D_PERRIN Wed Jul 17 1996 22:47 11

T.R	Title	User	Personal Name	Date	Lines
3702.1		TUBORG::D_PERRIN		`Wed Jul 17 1996 22:47`	11
	Hi. You probably want to post your question in the pathworks client notesfile. FWIW, all Digital ethernet adapters send out a MOP SYSID packet every 5-10 minutes. It provides a way if monitoring what nodes are on the lan. I believe that you can disable this from happening on a PC running Pathworks by adding the line: MOP = 0 in your protocol.ini's [DATALINK] section. I could not guess why a bad MOP packet would hang a pc.

    Hi. You probably want to post your question in the pathworks client
    notesfile. FWIW, all Digital ethernet adapters send out a MOP SYSID
    packet every 5-10 minutes. It provides a way if monitoring what nodes
    are on the lan. I believe that you can disable this from happening on
    a PC running Pathworks by adding the line:
    
     MOP = 0                                                                   
                                                                        
    in your protocol.ini's [DATALINK] section.
    
    I could not guess why a bad MOP packet would hang a pc.