System information

Troubleshooting Fiber Distributed Data Interface 5-75
show interfaces fddi
neighbor State of the neighbor:
• A—Indicates that the CMT
1
process has established a connection with its
neighbor. The bits received during the CMT signaling process indicate that the
neighbor is a Physical A type DAS
2
or concentrator that attaches to the primary
ring IN and the secondary ring OUT when attaching to the dual ring.
• S—Indicates that the CMT process has established a connection with its neighbor
and that the bits received during the CMT signaling process indicate that the
neighbor is one Physical type in a single-attachment station SAS
3
.
• B—Indicates that the CMT process has established a connection with its neighbor
and that the bits received during the CMT signaling process indicate that the
neighbor is a Physical B dual attachment station or concentrator that attaches to the
secondary ring IN and the primary ring OUT when attaching to the dual ring.
• M—Indicates that the CMT process has established a connection with its neighbor
and that the bits received during the CMT signaling process indicate that the
router’s neighbor is a Physical M-type concentrator serving as a master to a
connected station or concentrator.
• unk—Indicates that the network server has not completed the CMT process and, as
a result, does not know about its neighbor.
cmt signal bits Shows the transmitted/received CMT bits. The transmitted bits are 0x008 for a
Physical A type and 0x20C for Physical B type. The number after the slash (/) is the
received signal bits. If the connection is not active, the received bits are zero (0); see
the line beginning Phy-B in the display. This applies to FDDI processor FIP
4
interfaces only.
status Status value displayed is the actual status on the fiber. The FDDI standard defines the
following values:
• LSU—Line state unknown, the criteria for entering or remaining in any other line
state have not been met.
• NLS—Noise line state, entered upon the occurrence of 16 potential noise events
without satisfying the criteria for entry into another line state.
• MLS—Master line state, entered upon the receipt of eight or nine consecutive HQ
or QH symbol pairs.
• ILS—Idle line state, entered upon receipt of four or five idle symbols.
• HLS—Halt line state, entered upon the receipt of 16 or 17 consecutive H symbols.
• QLS—Quiet line state, entered upon the receipt of 16 or 17 consecutive Q symbols
or when carrier detect goes low.
• ALS—Active line state, entered upon receipt of a JK symbol pair when carrier
detect is high.
• OVUF—Elasticity buffer overflow/underflow. The normal states for a connected
Physical type are ILS or ALS. If the report displays the QLS status, this indicates
that the fiber is disconnected from Physical B, or that it is not connected to another
Physical type, or that the other station is not running.
Field Description