Datasheet

115
Release Notes for Cisco IOS Release 12.1E on the Catalyst 6500 and Cisco 7600 Supervisor Engine and MSFC
OL-2310-11
Limitations and Restrictions
To eliminate the load imposed on the MSFC CPU by the task of dropping denied packets and
generating ICMP-unreachable messages, do the following:
– With Supervisor Engine 1, enter the no ip unreachables interface configuration command.
– With Supervisor Engine 2, enter the no ip unreachables and the no ip redirects interface
configuration commands. (CSCdr33918)
• MAC address-based Cisco IOS ACLs are not supported for packets that are Layer 3 switched in
hardware. MAC address-based Cisco IOS ACLs will be applied on software-switched packets.
• If you enable multicast routing globally, then you should also enable multicast routing (using the ip
pim command) on all Layer 3 interfaces on which you anticipate receiving IP multicast traffic. This
command causes the packets to be sent to the process switching level to create the route entry. If you
disable multicast routing on the RPF interface, the entry cannot be created and the packet is dropped.
If the source traffic rate exceeds what can be handled by the process level, it can have an undesirable
impact on the system. For example, routing protocol packets, such as EIGRP hello packets, might
get dropped.
• 24-port 100FX switching modules (WS-X6224-100FX-MT) with a hardware version of 1.1 or lower
only support IEEE 802.1Q VLAN trunking; they do not support ISL trunking. Do not configure ISL
trunks on 24-port 100FX switching modules (WS-X6224-100FX-MT) with a hardware version of
1.1 or lower. The restriction against ISL VLAN trunking is the only known problem with hardware
version 1.1 or lower of these modules. If you do not require ISL VLAN trunking, these modules are
fully functional. The ISL VLAN trunking problem has been corrected in hardware version 1.2 or
later. If you want to return a WS-X6224-100FX-MT module with a hardware version of 1.1 or lower,
contact Cisco Systems. You can identify WS-X6224-100FX-MT hardware versions using one of
these two methods:
– Command-line interface (CLI) method—Enter the show module command to identify the
hardware version of the WS-X6224-100FX-MT module.
– Physical inspection method—The part number is printed on a label on the outer edge of the
component side of the module. Versions 73-3245-04 or lower do not support ISL trunking.
• The RJ-21 connectors on the 48-port 10/100TX switching module (WS-X6248-TEL) do not support
Category 3 RJ-21 telco connectors and cabling. Category 3 connectors and cabling cause carrier
sense errors. Use Category 5 RJ-21 telco connectors and cables (the module is keyed for Category 5
telco connectors and cables).
• The in and out ports displayed in Layer 3 table entries are set by the hardware at the time the entry
is created. They are not guaranteed to be accurate in case multiple flows use the same entry (for
example, if the flow mask is Dest-only and some kind of load sharing is active) or if the source or
destination of the Layer 3 entry moves in the Layer 2 topology. The port information is not always
available when the Layer 3 entry is established. This is the case if the destination port of the
rewritten packet is unknown when the shortcut is created.
• NetFlow Data Export (NDE) version 7 is not supported for MLS statistics exported from the MSFC.
NDE on the PFC supports the following NDE versions to export the statistics captured on the PFC
for Layer 3-switched traffic:
– Supervisor Engine 1 and PFC—NDE version 7
– Supervisor Engine 2 and PFC2:
NDE version 5 with Release 12.1(13)E and later releases
NDE version 7 with all releases
• For EtherChannels, you can configure the QoS trust state and default CoS directly on the
EtherChannel interface with the mls qos trust or mls qos cos commands, respectively. These two
parameters must be the same for all physical interfaces in the channel. No other QoS queueing