Conference netcad::hub_mgnt

2245.0. "Dual Homing to IBM 8250 HUB." by UTRTSC::GROOT_R (Ronald de Groot) Tue May 02 1995 11:52

	Hello,

	I have a quistion about dual homing to a IBM 8250 HUB. There
	is one DECswitch900MX with a dual homed connection to the 
	IBM 8250 HUB. In the 8250 there are two concentrators. One 
	Concentrators M port is going to port A of the DECswitch900MX
	the second concentrators M port is going to port B of the
	DECswitch900MX. This is a normal dual homing configuration 
	only it doesn,t work. It only works when port A or B is down.
	In hubwatch you can see that the Neighbor Port type is a S port
	instead of a M port! When on the 8250 concentrators the ports
	are changed to S ports Dual homing is working. But this is a
	ilegal configuration (S-port connected to A or B port). In 
	hubwatch the Neighbor Port type is still a S port. I known that
	this configuration is working with DECconcentrators but this 
	customer is a dealer from IBM network products and therefor
	used IBM concentrators.
	The quistion is has how is it possible that our switch see 
	S-ports that are M-port on IBM-concentrators and why is it only
	working when the IBMHUB is wronge configured. A simple answer 
	is that the 8250 HUB is a ... product but I don't nothing about
	IBM 8250 HUB products. (only the box from the outside and some 
	basic specs)

	Firmware rev's are V1.4 for the switch and V3.1 for the NAM.
	    
	Ronald
    
        

    
    The IBM 8250 is a Chipcom 5017C ONline Concentrator (with possible
    modifications). If you are unable to get assistance from IBM, I would
    call Chipcom Tech support and see if they can help. (they usually do)
    Phone : 800-228-6840
    
    regards,
    
    craig