Installation guide

Release Notes for the Cisco ME 3400 Ethernet Access Switch, Cisco IOS Release 12.2(44)SE

OL-14632-01

Limitations and Restrictions

• Although visible in the command-line help, the conform-action color policy-map class police

configuration command is not supported. Entering the command has no affect.

There is no workaround. (CSCsk00594)

SPAN and RSPAN

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

• The egress SPAN data rate might degrade when multicast routing is enabled. The amount of

degradation depends on the processor loading. Typically, the switch can egress SPAN at up to 40,000

packets per second (64-byte packets). As long as the total traffic being monitored is below this limit,

there is no degradation. However, if the traffic being monitored exceeds the limit, only a portion of

the source stream is spanned. When this occurs, the following console message appears: Decreased

egress SPAN rate. In all cases, normal traffic is not affected; the degradation limits only how much

of the original source stream can be egress spanned. If multicast routing is disabled, egress SPAN

is not degraded.

There is no workaround. If possible, disable multicast routing. If possible, use ingress SPAN to

observe the same traffic. (CSCeb01216)

• Some IGMP report and query packets with IP options might not be ingress-spanned. Packets that

are susceptible to this problem are IGMP packets containing 4 bytes of IP options (IP header length

of 24). An example of such packets would be IGMP reports and queries having the router alert IP

option. Ingress-spanning of such packets is not accurate and can vary with the traffic rate. Typically,

very few or none of these packets are spanned. There is no workaround. (CSCeb23352)

• When system jumbo MTU size is configured on a switch and the egress ports can support jumbo

frames, the egress SPAN jumbo frames are not forwarded to the SPAN destination ports.

There is no workaround. (CSCsj21718)

• Cisco Discovery Protocol (CDP) and Port Aggregation Protocol (PAgP) packets received by

network node interfaces (NNIs) 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. (CSCed24036)

Trunking

These are the trunking limitations:

• IP traffic with IP options set is sometimes leaked on a trunk port. For example, a trunk port is a

member of an IP multicast group in VLAN X but is not a member in VLAN Y. If VLAN Y is the

output interface for the multicast route entry assigned to the multicast group and an interface in

VLAN Y belongs to the same multicast group, the IP-option traffic received on an input VLAN

interface other than one in VLAN Y is sent on the trunk port in VLAN Y because the trunk port is

forwarding in VLAN Y, even though the port has no group membership in VLAN Y. There is no

workaround. (CSCdz42909).

• For trunk ports or access ports configured with IEEE 802.1Q tagging, inconsistent statistics might

appear in the show interfaces counters privileged EXEC command output. Valid IEEE 802.1Q

frames of 64 to 66 bytes are correctly forwarded even though the port LED blinks amber, and the

frames are not counted on the interface statistics. There is no workaround. (CSCec35100).