Cisco Cisco IOS Software Release 12.0 S

Symptoms: Performance Route Processor (PRP) crashes after loading image from disk0.

Condition: Occurs when multiservice edge (MSE) router reloads with the image in the disk0. The 
RP crashes, and tracebacks are displayed. Both the active and standby RPs toggle each time.

Workaround: There is no workaround. 

All the caveats listed in this section are resolved in Cisco IOS Release 12.0(33)S. This section describes 
only severity 1, severity 2, and select severity 3 caveats.

CSCsh63785

Symptoms: A MPLS tunnel may not come up after a stateful switchover (SSO) has occurred.

Conditions: This symptom is observed on a Cisco router when Cisco IS-IS NSF is enabled and when 
IS-IS is used as the IGP for MPLS TE tunnels.

Workaround: Do not configure Cisco IS-IS NSF. Rather, configure IETF NSF.

First Alternate Workaround: Enter the clear isis * command.

Second Alternate Workaround: Enter the shutdown interface configuration command followed by 
the no shutdown interface configuration command on the interface that is used for the MPLS TE 
tunnels after the SSO has occurred. 

CSCec12299

Devices running Cisco IOS versions 12.0S, 12.2, 12.3 or 12.4 and configured for Multiprotocol 
Label Switching (MPLS) Virtual Private Networks (VPNs) or VPN Routing and Forwarding Lite 
(VRF Lite) and using Border Gateway Protocol (BGP) between Customer Edge (CE) and Provider 
Edge (PE) devices may permit information to propagate between VPNs.

Workarounds are available to help mitigate this vulnerability. 

This issue is triggered by a logic error when processing extended communities on the PE device. 

This issue cannot be deterministically exploited by an attacker. 

Cisco has released free software updates that address these vulnerabilities. Workarounds that 
mitigate these vulnerabilities are available.

This advisory is posted at 

CSCek61276

Symptoms: IPv6 traffic stops.

Conditions: This symptom is observed on a Cisco router when you first disable and then re-enable 
IPv6 on an interface.

Workaround: Enter the shutdown interface configuration command followed by the no shutdown 
interface configuration command on the affected interface.