Cisco Cisco IOS Software Release 12.4(23)

CSCek26492

Symptoms: A router may crash if it receives a packet with a specific crafted IP option as detailed in 
Cisco Security Advisory: Crafted IP Option Vulnerability:

Conditions: This DDTS resolves a symptom of CSCec71950. Cisco IOS with this specific DDTS 
are not at risk of crash if CSCec71950 has been resolved in the software.

Workaround: Cisco IOS versions with the fix for CSCec71950 are not at risk for this issue and no 
workaround is required. If CSCec71950 is not resolved, see the following Cisco Security Advisory: 
Crafted IP Option Vulnerability for workaround information:

CSCek33253

Symptoms: NextPort modems that function in a T1 CAS signaling configuration do not dial all the 
DTMF digits successfully.

Conditions: This symptom is observed when you enter valid DTMF digits such as # and * in dial a 
string.

Workaround: Use MICA modems instead of NextPort modems.

Alternate Workaround: Use ISDN PRI T1 instead of T1 CAS signaling. 

CSCsa63173

Symptoms: CEF may not be updated with a new path label that is received from the BGP peer.

If a router configured for BGP IPv4+labels multipath receives a BGP update that only changes the 
MPLS label for a non-bestpath multipath, the router fails to update the forwarding plane. This results 
in dropping or mis-branding the traffic.

Conditions: In a IPv4+labels multipath setup, if a label is changed for the non-bestpath multipath 
and that is the only change in the new update received from the neighbor, the new label will not be 
programmed in forwarding, hence there will be label inconsistency between the BGP and the 
forwarding tables.

Workaround: There is no workaround. 

CSCsa86572

Symptoms: A large configuration in NVRAM on a primary or secondary RSP may become 
corrupted and the router may generate relevant warning messages during the execution of a copy 
system:running-config nvram: startup-config command.

When you erase NVRAM by entering the erase nvram command and then enter the copy 
system:running-config nvram: startup-config command, the router may crash.

Conditions: This symptom is observed on a Cisco 7500 series but is platform-independent.

Workaround: If the configuration file is significantly large, place a copy of the configuration file on 
a flash card or disk with ample space and enter the boot config slot0:startup-config command to 
force the startup configuration file to be read from the flash card.

When you enter the copy system:running-config nvram: startup-config command, the current 
running configuration is saved to the flash card or disk and the configuration is auto-synchronized 
to the corresponding flash card on the secondary RSP.

Caution: Do not remove the flash card while the boot config slot0:startup-config command is being 
executed.