Cisco Gigabit Ethernet Switch Module for HP BladeSystem p-Class Release Notes, Cisco IOS Release 12.2(25)SE1

SPAN and RSPAN

These are the SPAN and Remote SPAN (RSPAN) limitations.

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An egress SPAN copy of routed unicast traffic might show an incorrect destination MAC

address on both local and remote SPAN sessions. This limitation does not apply to

bridged packets. The workaround for local SPAN is to use the replicate option. For a

remote SPAN session, there is no workaround.

This is a hardware limitation: (CSCdy72835)

Egress SPAN routed packets (both unicast and multicast) show the incorrect source MAC

address. For remote SPAN packets, the source MAC address should be the MAC address

of the egress VLAN, but instead the packet shows the MAC address of the RSPAN

VLAN. For local SPAN packets with native encapsulation on the destination port, the

packet shows the MAC address of VLAN 1. This problem does not appear with local

SPAN when the encapsulation replicate option is used. This limitation does not apply to

bridged packets. The workaround is to use the encapsulate replicate keywords in the

monitor session global configuration command. Otherwise, there is no workaround.

This is a hardware limitation: (CSCdy81521)

During periods of very high traffic, when two RSPAN source sessions are configured, the

VLAN ID of packets in one RSPAN session might overwrite the VLAN ID of the other

RSPAN session. If this occurs, packets intended for one RSPAN VLAN are incorrectly

sent to the other RSPAN VLAN. This problem does not affect RSPAN destination

sessions. The workaround is to configure only one RSPAN source session.

This is a hardware limitation: (CSCed24036)

Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP), and Port Aggregation

Protocol (PAgP) packets received from a SPAN source are not sent to the destination

interfaces of a local SPAN session. The workaround is to use the monitor session

session_number destination {interface interface-id encapsulation replicate} global

configuration command for local SPAN.

Trunking

These are the trunking limitations:

The switch treats frames received with mixed encapsulation (802.1Q and Inter-Switch

Link [ISL]) as frames with FCS errors, increments the error counters, and causes the LED

to blink amber. This happens when an ISL-unaware device receives an ISL-encapsulated

packet and forwards the frame to an 802.1Q trunk interface. There is no workaround.

(CSCdz33708)

Cisco Gigabit Ethernet Switch Module for HP BladeSystem p-Class Release Notes, Cisco IOS Release 12.2(25)SE1 11