Segmentation Traps, Source Address Traps

Trap Selection

Segmentation Traps

Enterasys’ and Cabletron’s 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 hub number and port number associated with the trap.

Source Address Traps

The IRM2 can issue several different traps in response to changes in a port’s Source Address Table:

A newSourceAddress trap is generated when a station port — one receiving packets from no source addresses, or from a single source address — receives a packet from a source address that is not currently in its source address table. Information included in this trap includes the hub number, port number, and source address associated with the trap. Trunk ports — those receiving packets from two or more source addresses — will not issue new Source Address traps.

A sourceAddressTimeout trap is issued anytime a source address is aged out of the Source Address Table due to inactivity. The trap’s interesting information includes the hub and port index, and the source address that timed out. (See Chapter 4, Source Address Functions, for more information on the ageing time.)

PortTypeChanged traps are issued when a port’s topology status changes from station to trunk, or vice versa. The interesting information includes the hub and port index, and the port’s new topology status.

A lockStatusChanged trap is generated when the ports in the hub are locked or unlocked using the Lock/Unlock Ports option on the Repeater menus; the interesting information is the new lock status. (See Lock/Unlock Ports in Chapter 4 for more information.)

PortSecurityViolation and portViolationReset traps are sent in response to changes related to port locking: if ports are locked, the portSecurityViolation trap indicates that a new source address has attempted access on one of the ports, and the ports are being shut down in response; the interesting information is the hub and port index, and the violating address. PortViolationReset traps are sent

Trap Definitions

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