Cisco gear possible memory Load issue:
•Pay attention to log message, like ‘%SYS-2-MALLOCFAIL: …’ on Cisco device, run to the device to reboot it. The memory is leaking bad!! I found this: ‘%SYS-3-INVMEMINT: Invalid memory action (free) at interrupt level’ on Cisco 1920 router with IOS 15.1(4)M3 and Cisco openned a bug (#CSCtx59639). But not sure when there can be a fix…
•If “show” commands show nothing but blank screen, there is something wrong with memory on device.
•From serial console: “Unable to create Exec – No Memory OR Too many Processes”, that means something is wrong related memory.
•If wrong IOS image loaded, could be because of not enough memory.
•If bug in IOS image, there could be memory leak.
•Worn or Virus focus on IOS
•BGP could also load memory
If you find the above looks familiar, study the CCNP yourself, you might write some fancier ones 🙂