Cisco Cisco IOS Software Release 15.0(1)M

CSCtf26045

Symptoms: Ignored errors incrementing regularly even with low traffic when the traffic arrives on 
Multilink PPP, bundling multiple T1.

Conditions: This symptom is observed only when odd byte packets of size 273 arrive on the onboard 
hdlc driver. This leads to total traffic stoppage, especially if "qos preclassify" is configured on the 
tunnel interface.

Workaround: There is no workaround.

CSCtf28498

Symptoms: A Cisco router may crash when removing the service policy.

Conditions: This symptom is observed with QoS ACLs containing ICMP ACEs with either TTL, 
Reflect, or Option field-related entries.

Workaround: Do not use ICMP ACEs with TTL, Reflect or Option field-related entries. 

CSCtf31029

Symptoms: A Cisco HWIC-16A module configured on a Cisco 2900 router for asynchronous 
tunneling may not transmit escape characters (data payload) properly over IP to connected devices 
even though “escape-character none” is configured under the line.

Conditions: This symptom is observed on Cisco 2901, Cisco 2911, and Cisco 2921 platforms with 
Cisco HWIC-8A/16A or HWIC-4A/S modules and running any Cisco IOS release. This symptom 
does not occur on a Cisco 2951 platform.

Workaround: Use the AUX port. 

CSCtf34853

Symptoms: NS/NA packets are missing when enabling IPv6.

Conditions: This symptom is observed on Cisco routers with onboard GE interfaces.

Workaround: There is no workaround.

CSCtf49816

Symptoms: Tracebacks are seen while stressing the system.

Conditions: This symptom occurs when the CPU is stressed at more than 90% capacity. 

Workaround: Reduce the CPU to below 90%.

Cisco IOS Release 15.0(1)M1 is a rebuild release for Cisco IOS Release 15.0(1)M. The caveats in this 
section are resolved in Cisco IOS Release 15.0(1)M1 but may be open in previous Cisco IOS releases.

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Symptoms: The interface MTU is not user configurable. When you attempt to configure “interface 
level command mtu”, the following message is printed:

% Interface {Interface Name} does not support user settable mtu.

Conditions: The symptom is observed with a 2-Port FE on a Cisco 7200 series router.

Workaround: There is no workaround.

Further Problem Description: The Cisco.com document entitled “MPLS MTU Command Changes” 
further discusses this enhancement.