60.1 Unexplained Phenomenon Cisco Forum FAQ | DSLReports.com, ISP Information

Following is the "weird situation" relating to Frame Relay

»One app didn't work over Frame Relay; worked over ISDN

by aryoba

It is "unwritten rule" in Cisco IOS router network management that older IOS version such as 12.3.x is considered more reliable than the newer IOS 12.4.x. for routers that are really meant to run 12.3 IOS image version. For routers that are meant to run 12.4.x IOS image version such as 3800, 2800, and 1800 series; you should not run 15.x IOS image version on those platform due to stability. Further, sometime upgrading IOS image version solves weird problems.

Check out following thread for illustration.

Downgrade from 12.4.x to 12.3.x
»Cisco 2621XM, Poor Performance with WIC-1ADSL, IOS 12.4
»[HELP] Cisco 877: connection drops when launching Emule

Upgrade from older 12.3.x to newer 12.3.x
»[Config] Cisco 2801 + WIC-1T problem
»[HELP] Cisco 7200 VXR uses up all of the I/O memory

Unidentified interface with factory-shipped IOS image
»[Config] Cisco router 867 what is the DSL interface?

Upgrade IOS image version for possible solutions
»Cisco 2821 ISR w/ Bad Ping, Error Inputs, CRC Errors & FiOS

CME-related bug
»[Config] Adding 7920 knocks other phones off CME

Check out this FAQ for possible bug within the IOS image that might explain the phenomenon.
»Cisco Forum FAQ »Where can I find Field notices to confirm to during troubleshooting?

by aryoba
last modified: 2012-04-12 12:56:51

by aryoba
last modified: 2010-04-24 07:04:13