Datasheet

113
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
• Integrated routing and bridging (IRB) and concurrent routing and bridging (CRB) have deliberately
been disabled on the Catalyst 6500 series switches and Cisco 7600 Series Routers. You should use
routable Layer 2 VLANs and VLAN interfaces for normal bridging and interVLAN routing. Bridge
groups are supported only to bridge nonrouted protocols.
• With Release 12.1(6)E or later, FlexWAN module interfaces support dNBAR. Do not configure
NBAR on other interfaces.
• Catalyst 6500 series switches and Cisco 7600 Series Routers do not support remote source-route
bridging (RSRB).
• All Ethernet LAN ports on all modules, including those on a redundant supervisor engine, support
EtherChannel (maximum of eight interfaces) with no requirement that interfaces be contiguous.
• With a PFC2 and DFCs, QoS ignores policy maps attached to an EtherChannel formed from
interfaces on different DFC-equipped switching modules.
• To avoid a reload with redundant Switch Fabric Modules, if you perform any of these operations on
the active Switch Fabric Module, wait at least 15 seconds before you perform any of these operations
on the other Switch Fabric Module:
– Removing the Switch Fabric Module
– Inserting the Switch Fabric Module
– Entering commands to power cycle the Switch Fabric Module
– Entering commands to power down the Switch Fabric Module
– Entering commands to power up the Switch Fabric Module
(CSCdt43548)
• Ingress IP Packets with TTL=1 that are not addressed to the MSFC2 and that match QoS filtering
parameters might cause overpolicing of other ingress traffic on the same ingress interface.
• With PFC2 (and DFCs, if present), the hardware FIB supports 256K entries, which includes 16K IP
multicast entries. With RPF check enabled, there are twice as many IP entries in the FIB.
• With PFC2 (and DFCs, if present), hardware CEF-switching uses per-flow load balancing, based on
IP source and destination addresses. For any given packet, all PFC2- and DFC-equipped switches
make exactly the same load-balancing decision, which can result in nonrandom load balancing.
• When the outgoing interface list for group G traffic transitions to null on a last-hop multicast router,
the router sends a (*,G) prune message to the PIM neighbor toward the rendezvous point (RP) to
stop the flow of group G traffic (if any) down the shared tree, but does not send an (S,G) prune
message to stop the flow of traffic down the shortest path tree (SPT). The transition of the outgoing
interface list to null does not trigger an (S,G) prune message. (S,G) prune messages are triggered by
the arrival of (S,G) traffic.
If the last-hop multicast router is a Catalyst 6500 series switch, traffic is forwarded by the PFC2. In
most cases, RPF-MFD is installed for the (S,G) entries. The MSFC2 does not see the multicast
traffic flowing down the SPT and does not send any traffic-triggered (S,G) prunes to stop the flow
of traffic down the SPT. This situation does not have any adverse effect on the MSFC2 because the
PFC2 processes and drops the unwanted (S,G) traffic.
• With a PFC2, if you enter the mac mac_address interface command, the configured MAC address
is used for all Layer 3 VLAN interfaces and Layer 3 LAN ports.
• The PFC2 supports a maximum of 1 Gateway Load Balancing Protocol (GLBP) group.
• The PFC2 supports a maximum of 16 unique Hot Standby Routing Protocol (HSRP) group numbers.
– You can use the same HSRP group numbers in different VLANs (for example, use 1 as the first
group number in each VLAN, 2 for the second, etc.).