Enterasys SmartSwitch 6000, User Manual

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Managing Ethernet MicroLAN Modules
5-26 Trap Selection
You can change trap settings from any level window; however, if you have established
individual trap settings for any ports, remember that enabling and disabling traps from the
repeater- or module-level windows will override those individual setting. Remember, too,
that setting trap selection state at the repeater and module levels accomplishes the same
thing, as each “board” on the Ethernet MicroLAN module is a repeated network.
Trap Definitions
You can enable or disable the following kinds of traps:
Link State Traps
Some Enterasys Ethernet repeater ports – including RJ45 twisted pair and fiber optic ports
– generate a link signal to monitor the status of their connection with the device at the
other end of the cable segment. If the cable is removed or broken, the port’s link status
goes to “No Link” and the repeater generates a portLinkDown trap. When a port in a “No
Link” condition receives a link signal, the port goes to a “Link” condition and the repeater
generates a portLinkUp trap. Devices at both ends of the disconnected or broken cable
will generate the portLinkDown and portLinkUp traps, even when only one end of the
cable has been removed.
Note that BNC (thin coax), AUI, and transceiver ports do not support a link signal. BNC
ports respond to changes in link status by generating portSegmenting and
portUnsegmenting traps (see description, below); AUI and transceiver ports do not
respond at all to changes in link status (unless the port has been segmented due to
excessive collisions), and will always display as on, even if no cable is connected.
Information included in a Link State trap will include the board number and port number
associated with the trap.
Segmentation Traps
Enterasys’ Ethernet repeaters count collisions at each port. If a port experiences 32
consecutive collisions, or if the port’s collision detector is on for more than
2-3 µs, the repeater segments the port to isolate the source of the collisions from the rest of
the network. When the repeater segments a port, it generates a portSegmenting trap. As
soon as a segmented port receives a good packet, the repeater reconnects the port to the
network and generates a portUnsegmenting trap.
Note that, because they do not support the Link signal, unterminated BNC (thin coax)
ports appear as segmented. When you attach a thin coax cable or a terminator to a port, the
repeater generates a portUnsegmenting trap; when you remove the cable or terminator,
the repeater generates a portSegmenting trap. As mentioned above, these traps can serve
as notification of changes in link status. Note, too, that devices at both ends of the cable
segment will generate the portSegmenting and portUnsegmenting traps, even if only
one end of the cable has been disconnected.
Information included in a Segmentation trap will include the board number and port
number associated with the trap.