Cisco Cisco IOS Software Release 12.4(22)XR

The “

” section lists open caveats that apply to the current release; they may also apply to 

previous releases.

The “

” section lists caveats resolved in a particular release that may have been open in 

previous releases.

The “

” section describes the product documentation that is available.

If you have an account with Cisco.com, you can use Bug Navigator II to find caveats of any severity for 
any release. You can access Bug Navigator II on Cisco.com at Software Center: Cisco IOS Software: 
Cisco Bug Toolkit: Cisco Bugtool Navigator II, or at 

The following are the unresolved caveats in Cisco IOS Release 12.4(22)XR5 and earlier releases.

 lists the unresolved caveats in Cisco IOS Release 12.4(22)XR5.

CSCtc92933

When an IP packet of size 1,500 bytes with the DF-bit set 
is sent to a mobile, Cisco PDSN Release 5.2 routes the 
packet incorrectly. This behavior occurs for mobiles that 
negotiate ACCM as zero and IXP does the AHDLC 
encoding. When the IP packet is encapsulated with PPP 
and IP/GRE, the packet exceeds 1,500 egress MTU size 
and fragments at the A10 level in PPC.

Configuring the MTU to 
1,600 bytes ensures that 
the packet (after A10 
encapsulation) does not 
fragment and is 
forwarded to the IXP.