Technical Background; Figure 12. Two Separate Ethernet Clouds - Olicom CrossFire 8730 Reference Manual

30
.
Primary CRF
FORWARDING
STACK-LINK
STATUS
FAULT
TX RX ATTACH 21-22 21
MANAGEMENT PWR DIAG ERR RST
5 6 7 8
1 2 3 4
Token-Ring

Figure 12. Two Separate Ethernet Clouds

Note: The CRF connection attribute can be set from the console or via ClearSight.

Technical Background

For each CRF with a Fast Ethernet port, the spanning tree protocol should be
enabled. For SRT CRF, the default STP algorithm is IEEE 802.1D. Only this
spanning tree algorithm can be used for Fast Ethernet ports.
A Fast Ethernet port has its own LAN segment number and recognizes source
routing. However, the Fast Ethernet port is an element of a transparent network and
frames are passed through only in forwarding state. This restriction is applied to all
frames, including ARE and specifically routed frames.
Only one link of a CRF at a time may become forwarding. To achieve this, the
spanning tree costs of the internal BRF to CRF link will be modified according to
the CRF connection attribute. The BRF to CRF link is a virtual internal link and
exists only for spanning tree purposes.
The spanning tree cost of each primary connection remains unmodified.
Note that in the Secondary 1 and Secondary 2 connections, different values are
added to the cost of the internal BRF to CRF link in order to make sure that
CrossFire 8730 Switch Reference Guide, DOC-7047 v. 1.1
Ethernet cloud
CrossFire 8730
Fast Ethernet Translation Switch
ACT ACT ACT ACT
100 100 STATUS 100 100
LINK LINK LINK LINK
FAULT
22 FAST ETHERNET 25-26 25 26
9 10 11 12 13 14 15 16 17 18 20
19
cloud
SR Bridge
Secondary CRF
BLOCKING
STACK-LINK
STATUS
FAULT
TX RX ATTACH 21-22 21
MANAGEMENT PWR DIAG ERR RST
1 2 3 4 5 6 7 8 9
Token-Ring
cloud
Ethernet cloud
Primary CRF
FORWARDING
CrossFire 8730
Fast Ethernet Translation Switch
ACT ACT ACT ACT
STATUS
100 100 100 100
LINK LINK LINK LINK
FAULT
22 FAST ETHERNET 25-26 25 26
10 11 12 13 14 15 16 17 18 19 20
Switch Overview