| 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 |
Some questions on FDDI configs in the DEChub900.
I've read Karl Pieper's document about the FDDI-configuration rules in the
DEChub 900.
I understood that M and S ports are not yet supported on the backplane but
can I have M and S ports on the front of a DB900MX.
This is the config I want to establish.
Front Panel Ports
A E E M E B
| |
| | S M S M S M
| +---|--------------+ +---------------+ +---------------+
| | | | | | | |
+-+-+-+-+-+-+-+ +---------+-+-+ +---------+-+-+ +---------+-+-+
| CONC 1 | | BRID 1 | | BRID 2 | | BRID 3 |
+-------------+ +-------------+ +-------------+ +-------------+
Backplane Ports
E= Empty
A and B port on concentrator are Single Mode.
An alternative solution could be to connect each bridge to a separate M-port
of the concentrator. But since A and B port on the the concentrator are SM I
need to leaf the adjacement ports empty. So, I have only two M-ports available
for three bridges.
My second question: Does spanning three detects loops between ports of the
same bridge (DB900MX) and can one of the ports go in backup mode ?
Or does it only detect loops between bridges ?
regards...........Peter
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1266.1 | No. DB900 can't be a SAC (yet) | NACAD2::PARISEAU | Luc Pariseau | Tue Aug 02 1994 10:29 | 6 |
The bridge cannot yet be configured to be a SAC (on the front nor the back.) Luc | |||||
| 1266.2 | Loops on adjacent ports of same bridge will be detected... | NACAD2::BATTERSBY | Tue Aug 02 1994 13:47 | 8 | |
>My second question: Does spanning three detects loops between ports of
>the same bridge (DB900MX) and can one of the ports go in backup mode ?
>Or does it only detect loops between bridges ?
Yup loops will be detected between ports of the same bridge.
the higher numbered port will be the one to go into backup.
Bob
| |||||
| 1266.3 | Loopback detected between bridges? | ROM01::GALLANA | Wed Oct 19 1994 13:19 | 23 | |
Hello,
you said that the DB900MX detects the loopback between two o more
Ethernet ports but I dont' understand if the loopback is detected
also between two different Bridges connected via FDDI, each having
1 Ethernet port connectred to the same Ethernet channel.
HUB900MS
+--------------------+---+---+
| | | |
| | X | X | <--+ Ports connected via FDDI
| | X | X | <--+
| | | |
| | | |
| | . | . | -------- Ethernet channel
| | | |
| | | |
+--------------------+---+---+
Bye
Francesco
| |||||
| 1266.4 | Why not! | CGOS01::DMARLOWE | Have you been HUBbed lately? | Thu Oct 20 1994 01:45 | 12 |
Loops will be detected between bridges if both the FDDI and 1 or
more Ethernets are connected. The ultimate in redundancy would
be to put 2 DECswitches in a single hub, FDDI them together and
then connect the 6 Ethernets to the backplane, pairing the ports
of the switches (bridges) to individual channels. That way one
switch will be in standby waiting for a failure of an FDDI or Ethernet
port or worse yet, the complete failure of a whole switch.
Hey, its only spanning tree, so what if it happens to have a half
dozen more ports.
dave
| |||||