Cisco Cisco IOS Software Release 12.0 S Release Notes

Symptoms: A Cisco 7500 series router that acts as the penultimate hop of the backup Label 
Switched Path (LSP) and that is configured with the mpls traffic-eng signalling interpret 
explicit-null verbatim router configuration command may have the primary LSP go down when 
Fast ReRoute (FRR) is enabled on the router.

Conditions: This symptom is observed on a Cisco 7500 series that has Multiprotocol Label 
Switching (MPLS) traffic engineering (TE) configured.

Work around: Do not configure the mpls traffic-eng signalling interpret explicit-null verbatim 
router configuration command.

CSCdz42789

Symptoms: When you configure a Virtual Private Network (VPN) on a router that is configured with 
dual Route Processors (RPs), a VPN routing/forwarding (VRF) table ID that is associated with a 
particular VRF instance may have different values in the active RP and the standby RP. This 
situation causes failures in the processing of Cisco Express Forwarding (CEF) interprocess 
communication (IPC) messages on the standby RP for CEF IPC messages that contain an 
inconsistent VRF table ID, and CEF may be disabled.

Inconsistent VRF table IDs may also cause a memory loss on the standby RP, and when a switchover 
occurs from the active RP to the standby RP, more difficulties may occur.

Conditions: These symptoms are observed on router that is configured for Stateful Switchover 
(SSO) when VRF instances are deleted.

Workaround: There is no workaround; however, these actions minimize the occurrence of the 
symptoms:

Ensure that no VRF instances are deleted.

If VRF instances are deleted, wait for few minutes for the deletion to be completed on the active 
RP before you configure new VRF instances. The output of the show ip vrf EXEC command 
displays the deleted VRF instances (a “*” in front of a VRF instance indicates that the VRF 
instance is being deleted).

If you install a new RP and VRF instances have been deleted from the configuration of the active 
RP, reload the router. 

CSCdz53693

Symptoms: The ip access-,group interface configuration command does not function on a 
PortChannel interface.

Conditions: This symptom is observed in Cisco IOS Release 12.0(23)S1.

Workaround: There is no workaround. 

CSCdz54497

This caveat consists of two symptoms, two conditions, and two workarounds:

Symptom 1: The interface index of a tunnel interface may be corrupt, and the output of the show 
running-config privileged EXEC command may display the following information:

%FIB-2-IFINDEXILLEGAL: An internal software error occurred. Argument ifindex is out 

of bounds at -1.

Condition 1: This symptom is observed on a Cisco 7500 series after a switchover has occurred and 
you first add a tunnel interface, then remove the tunnel interface, and then add the tunnel interface 
again.

Workaround 1: There is no workaround.