| 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 |
The old DEREP repeaters had a feature that allowed you to connect 2 DEREPs in parellel, and one would detect the loop and stop passing frames, until the first DEREP failed. Question: did this capability get carried over into the 90FA or any of the other current repeaters? Question: What options does a customer have, without buying a bridge, for redundantly coupling two hubs together - preferably using fibr optic connections? In fact what the customer has asked, is if he has four hubs, and he wants to connect two of them onto a 10Base5 backbone, and then connect two remote hubs over fibre, to BOTH OF THE two hubs on the 10Base5, can he do it without a bridge? (i.e. A to B on 10B5, C to A+B, and D to A+B) Thanks Tim
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 687.1 | QUIVER::SLAWRENCE | Thu Feb 03 1994 13:17 | 85 | ||
For the first part of the question, see the announcements for the
DEFMI and DEFMM; they support redundant optical links.
If I understand your question correctly (we'll see...) then you can't,
but you can accomplish what you want (I think).
Your customer asked if this was ok:
+-----------+ +-----------+
| | | |
| A | | B |
| | | | A, B, C, & D
| |+| | | |+| | are repeaters
+-|-|-----#-+ +-#-----|-|-+ (in hubs or not)
| | ####################### | |
| \ / |
| \ ___________/ | Thin lines are fiber.
| \_______________ / __________ |
| _________________/ \ | ### is a repeater link
| / \ |
| | | |
+-|-|-------+ +-------|-|-+
| | | | | | | |
| C | | D |
| | | |
| | | |
+-----------+ +-----------+
The answer here is that it is not ok; for a redundant link pair
(shown here as '|+|') to operate correctly both ends must go to a
single pair of devices, not three as shown here. The problem is
(for example) that a path A->B->C->A exists.
But there are two ways of getting what you need; read on...
If you don't mind bridges, then the same configuration works, but
the devices connecting hubs are bridges. Spanning tree will deal
with the extra links to prevent loops:
+-----------+ +-----------+
| | | |
| A | | B |
| | | | A, B, C, & D
| | | | | | | | are bridges
+-|-|-----#-+ +-#-----|-|-+ (in hubs or not)
| | ####################### | |
| \ / |
| \ ___________/ | Thin lines are fiber.
| \_______________ / __________ |
| _________________/ \ | ### is a repeater link
| / \ |
| | | |
+-|-|-------+ +-------|-|-+
| | | | | | | |
| C | | D |
| | | |
| | | |
+-----------+ +-----------+
If you don't want bridges, then you can do this:
+-----------+ +-----------+
| | | |
| A | | B |
| | | | A, B, C, & D
| |+| | | |+| | are repeaters
+-|-|-----#-+ +-#-----|-|-+ (in hubs or not)
| | ####################### | |
| | | |
| | | | Thin lines are fiber.
| | | |
| | | | ### is a repeater link
| | | |
| | | |
+-|-|-------+ +-------|-|-+
| |+| | | |+| |
| C | | D |
| | | |
| | | |
+-----------+ +-----------+
Which deals with link failures but not hub failures.
| |||||
| 687.2 | QUIVER::SLAWRENCE | Thu Feb 03 1994 13:54 | 2 | ||
See also 581.2
| |||||
| 687.3 | Thanks | WARNUT::2H0533::Tim_Banks | Stealth Marketing :-) | Fri Feb 04 1994 04:15 | 8 |
Hi S Thanks for the very comprehensive reply, much appreciated, sadly the DEFM* announcements will be just too late I suspect. Thanks Tim | |||||
| 687.4 | announcement is next week | DELNI::GIUNTA | Fri Feb 04 1994 09:23 | 7 | |
The DEFMI and DEFMM will be announced next Tuesday, Feb 8 with a 60-90 day availability as I'm expecting FCS in April and volume availability in May. Since it sounds like this is too late for you, when does your customer need to have his equipment installed, and how many do you need? Regards, Cathy | |||||