| Title: | DEChub/HUBwatch/PROBEwatch CONFERENCE |
| Notice: | Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7 |
| Moderator: | NETCAD::COLELLA DT |
| 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 |
I have a customer who wishes to know if the following configuration
will work. Am explanation and questions follow the diagram.
The config is as follows;
lan A
|
________ |--------------- Rep A----
|Server A|-----| lan B |---- 5 * W/S
-------- ------------- | |
| | |
| | |
| | |
-------- | | |
|Server B|-----| | |
-------- ------------- | |
| | |
| |------ Rep B----
| |
Explanation:
The two servers are attached to two segments of ethernet.
These segments then have 1 * DECrepeater 90C connected.
The two respective DECrepeater 90C's are connected by 6 * segments of
thinwire (ie Port 1 on Rep A goes to Port 1 on Rep B), each of the
6 segments then has 5 * workstations daisy chained.
Questions:
Is this configuration legal ?
What is the impact on the servers in as much as a destination ethernet
address will be available down two channels on the same system ?
By powering down 1 repeater, will it render the whole network dead ?
I look forward to any assistance.....
&*)
Toto
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 971.1 | loopy | QUIVER::SLAWRENCE | Thu May 12 1994 13:00 | 53 | |
NO. The configuration as described will definitly not work. Expanding the picture to show all the repeater connections shows why: > > lan A > | > ________ |--------- Rep A----+ > |Server A|--| lan B ----|-+ > -------- ------- | ----|-|-+ > | | ----|-|-|-+ > | | ----|-|-|-|-+ > | | ----|-|-|-|-|-+ > -------- | | ----|-|-|-|-|-|-+ > |Server B|--| | | | | | | | | > -------- ------- | | | | | | | | > | | | | | | | | | > | |--- Rep B----+ | | | | | | > | | ------+ | | | | | > --------+ | | | | > ----------+ | | | > Explanation: ------------+ | | > --------------+ | > ----------------+ > > The two servers are attached to two segments of ethernet. > > These segments then have 1 * DECrepeater 90C connected. > > The two respective DECrepeater 90C's are connected by 6 * segments of > thinwire (ie Port 1 on Rep A goes to Port 1 on Rep B), each of the > 6 segments then has 5 * workstations daisy chained. You have 6 connections (the thinwires) between two repeaters; counting the (large) number of loops in this configuration is left as an exercise for the reader. It appears that what your customer wants is redundant connections to the servers; this is ok, so long as the servers are not doing any kind of relay (routing or bridging). As long as there is _no_ other repeater connection from Lan A to Lan B, you could do what you want with 90C repeaters _IF_ you put all 30 workstations on just 1 thinwire between the two repeaters. This would provide redundant connections to the servers and the two Lans for each workstation. As far as the workstations are concerned, this is the same as before (except that they are not in a loop, so the ethernet will not always be full :-). It looks as though your customer doesn't fully understand the difference between a repeater and a bridge. A repeater does not provide each port with a separate collision domain - every bit is repeated onto every port, including collisions. | |||||