View source for Compare Running Config With A Previous Config

To see what changes have been made to the running config on a Cisco device since the last save, you an do a compare with the startup config.  

<PRE>
show archive config differences nvram:startup-config system:running-config
</PRE>

The output shows the differences in the latter file (the running-config, in this case).  Any line beginning with a '''+''' is an addition.  Conversely, anything beginning with a '''-''' has been removed.

====Example====
<PRE style="color:white;background-color:black;font-weight:bold;font-size:1.2em;">
ROUTER#$show archive config differences nvram:startup-config system:running-config
Contextual Config Diffs:
+interface Vlan3
 +ip address 2.2.2.2 255.255.255.0
interface Vlan2
 -description WAN
</PRE>

You can replace '''nvram:startup-config''' with any config that has been archived using the procedure in [[Automatic Config Archiving]].

====Example====
<PRE style="color:white;background-color:black;font-weight:bold;font-size:1.2em;">
ROUTER#$show archive config differences tftp://10.10.10.5/ROUTER-autoarchive-May-29-10:11:35.187-EDT-13 system:running-config
Contextual Config Diffs:
+interface Vlan3
 +ip address 2.2.2.2 255.255.255.0
interface Vlan2
 -description WAN
</PRE>

To make your router feel more like a Juniper, add this to your config:

<PRE>
alias exec compare show archive config differences nvram:startup-config system:running-config
</PRE>

Then you just need to type "compare" to see what changes have been made since you last saved your config.