Netreo says my Cisco device configuration is not saved, but it is. What’s happening?

In certain cases, Cisco configurations may show as “Changed but not saved!” even though they have been saved, or not changed in a long time.

This is caused by a quirk in the way Cisco counts time. Netreo uses SNMP to check configuration “save status” on Cisco devices. Cisco limits the response on these counters to 32 bits, and they read in “uptime in hundredths of seconds.”

This means the counters “roll over” to zero after approximately 497 days.

In rare cases, this can generate false alarms. If the router has been running a long time (high uptime) and the configuration hasn’t been changed, but the router has had a “write memory” or “write startup-config” performed more recently, the “Last configuration change time” can become a higher number than the “Last configuration save time” (because the counter rolled over to zero between the last change and the save).

This will cause Netreo to think the configuration was changed after the last write.

A simple workaround is to make a change to the router configuration. Any change will do, and you can undo it immediately afterwards (for example, change or add a description line and then resave the configuration). This resets the counters and clears the error. You could also reboot the router, but this will impact traffic flow through the device.