Specifications

33
Caveats for Cisco IOS Release 12.0
78-6455-12
Resolved Caveats—Cisco IOS Release 12.0(12)
ISO CLNS
• CSCdm91745
On Cisco routers, if a DECnet packet is received on an ethernet interface and is converted to a
CLNS packet, in the unlikely event that it cannot be routed to its destination, an unexpected reload
might occur in ether_extract_addr. There is no workaround.
Miscellaneous
• CSCdp56613
When fast switching an IP frame that is fewer than 46 bytes in length to an ATM interface, the
router always sets the length in the ATM adaptation Layer 5 (AAL5) header to 54 bytes even though
the length should be equal to the IP frame length plus the length of the AAL5 header, which is 8
bytes. There is no workaround.
• CSCdr00694
A Cisco router that is running Cisco IOS Release 12.0(9)S or later releases might experience
problems if you attempt to format, delete, or squeeze slot0: immediately after the show version
command is entered or immediately after the router reloads. This is a flash timing-related issue, and
subsequent commands that you enter will not be effected. There is no workaround.
• CSCdr28140
A Cisco router (800 series through 4700 series) might silently drop large packets. This situation
occurs when both Cisco Express Forwarding (CEF) and output rate-limiting are enabled on an
interface, and a packet to be switched out of an interface is larger than the maximum transmission
unit (MTU).
Workaround: Disable CEF or disable the Committed Access Rate (CAR) on interfaces that will
need to fragment packets.
• CSCdr55357
A Cisco router that is configured with Multiprotocol over ATM (MPOA) and Cisco Express
Forwarding (CEF) might create an ingress cache and an egress cache with the same IP address, and
the egress MPOA Client (MPC) address of the ingress cache points to itself. This situation might
create a routing loop that causes the router to function improperly. This situation might occur
during the route transitions in the network caused by topology changes.
Workaround: Clear the CEF adjacencies using the clear adjacency EXEC command. Clear the
corresponding ingress and egress caches using the clear mpoa client cache [ip-address
ip-address] EXEC command.
• CSCdr63500
Configuring a Cisco Route Switch Processor RSP with Multiprotocol over ATM (MPOA) and Cisco
Express Forwarding (CEF) might lead to data loss when CEF uses the virtual channel connection
(VCC) that was created by MPOA Client for data transfer in the following cases:
Absence of MPOA client ingress cache
Absence of the VCC created by MPOA Client
Workaround: Clear the CEF adjacencies using the clear adjacency EXEC command.