Installing and Administering HP FDDI/9000 Software

Chapter 1 29
FDDI Resources
FDDI Concepts
Figure 1-4 FDDI Dual Ring In Wrap Mode
Together the A and B ports determine the attachment configuration of
the station or concentrator. In Figure 1-4 showing an FDDI ring in wrap
mode, the CF_State of both the inactive and active stations has changed
to reflect the new ring configuration. The CF_State of the mainframe,
which is no longer operational, is now Isolated, the CF_State of the
concentrator at MAC address 080009001023 is Wrap_A, because its
MAC is now transmitting the data stream back out the A port, and the
CF_State of the concentrator at MAC address 080009005067, is Wrap_B
because its MAC is now transmitting the data stream back out the B
port. The possible attachment states of single-attached stations are
Wrap_S or Isolated. Wrap_A and Wrap_B are fault recovery states.
Wrap_S is a normal state. (Refer to Figure 1-5 for an illustration of
single-station attachment configurations. Refer to the fddistat(1M)
manpage for more information.)
B
A
M3
B
B
B
A
A
A
M2
M1
M3
M2
M1
Concentrator (DAC)
CF_State = Thru_A
MAC Address =
080009005067
to SAS
to SAS
to SAS
DAS = Dual Attach Station
DAC = Dual Attach Concentrator
A, B, M and S = Port Types
Mainframe (DAS)
CF_State = Thru_A
MAC Address =
080009004056
Concentrator (DAC)
CF_State = Thru_A
MAC Address =
080009001023
Router (DAS)
CF_State = Thru_A
MAC Address =
080009002034
to SAS
to SAS
to SAS
MAC
MAC
802.3
MAC
MAC
MAC