Conference netcad::hub_mgnt

2701.0. "Strange hub based network problem" by CHEFS::CANTY () Fri Sep 01 1995 13:13

        I have a weird customer problem and wonder if anyone has experienced
        anything like this before. Our customer has approx 20 DEChub90
        connected mainly via fibre, these hubs all ultimately connect to one
        main hub, connected to this hub via thinwire is a bridge, which is
        linked via a bridged 256k kilostream link into the Digital office in
        Newbury where their VAX systems are located.

        It seems that when one of the hubs (not the main hub) hanging off one
        particular fibre link is powered off then this causes all the hubs in
        the network to lose access to the remote VAX systems. This
        problem has happened on at least three occassions and each time it has
        been proved to be due to the fact one of the hubs hanging off this
        particular fibre has been powered off.  As soon as power is restored to
        the hub then all hubs have access to the remote VAX systems.

        This particular fibre is connected to the main hub via a standalone
        DECrepeater90fl, and then is onward linked via fibre to the other hubs
        in the area that we have the problems. We have moved the fibre to a
        different fibre repeater in the main hub but this made no difference.

        Whilst the hub was powered off I monitored activity on the lan port of
        the bridge at the customer site and could see no receive activity.

        Any ideas ????????.

                        Thanks for any assistance,

                                Stuart Canty.