Running config - Startup Config - SW

[mcinar]

Hi,

One of our customers asked me that their Start-up Config and Running Config are different from each other.

When I look at them, info in the same line numbers are different but the config there. For exmaple if vlan info are between 78-90 lines in Startup Config, on 78-90 lines in Running Config, there is no info. But these vlan info are in another lines in Running config.

Is this a normal situation?

Regards,

Melih 

[marce1000]

  - Startup-config may contain some additional headers when being generated and or saved from running config. Nothing to worry about.

 M.

[Martin L]

yes, normal situation; some things - commands- in start config are loaded into memory but not seen on show run

vlans are stored in vlan database but not in start config unless VTP mode is transparent

[Richard Burts]

We tend to think of both running config and startup config as being text files. And in that context it is logical to assume that the same entry would be on the same line number if both configs are in sync. While startup config is like a text file the running config is really not like a text file. running config is a dynamic data structure in memory of the device. When we do show run the device evaluates its dynamic data structure and produces what we see as running config. It is certainly likely that the parser that is building the representation of the data structure may insert some extra ! spacing lines, or some type of comment line that means that line numbers will not match. This is certainly the normal behavior and not an issue when the line numbers do not match.