Definition

A Bus Error exception occurs when the software attempts to read or write to an invalid memory or I/O address. It is a software defect. Bus errors can also occur when the software is unable to read or write to valid memory and I/O addresses, this is a hardware defect.

To troubleshoot bus error exceptions on Cisco IOS devices, first issue the router#show version IOS EXEC command and an error message similar to the following should be displayed if the device has not been power-cycled since the crash.

System restarted by bus error at PC 0x53FF4598, address 0xDDF67359

The example above indicates that the software tried to access 0xDDF67359 unsuccessfully.

Now, issue the router#show region IOS EXEC command to see if the address 0xDDF67359 is either;

• Invalid
• Valid and falls in a read-write region
• Valid and falls in a read-only region.

If the address is:

A - Invalid - it is a software defect. Search for bus error bugs on mysolvr and OEM website

B - Valid and the address falls in a read and write region. This is a hardware issue. Try reseating the hardware components and if it fails again, replace the impacted component.

C - Valid and the address falls in a read-only region. This could be a hardware or software issue. Try reseating the hardware first and if it fails again with an address in a similar region, do a bug search and seek a software solution as advised in solution A above. Note The "cause code" in the crashinfo file is a definitive way to confirm whether this is a software or hardware issue.

See Troubleshooting Bus Error Crashes for more  tips on Cisco  platforms