Auto summary was the default until more recent releases. When it's enabled networks are automatically summarized when crossing major network boundaries. This behavior is usually not wanted in modern networks.
If a router has an interface with 10.0.0.1/24 on one interface towards a LAN and an interface with 172.16.0.1/24 on an interface towards another router it is peering with. Then the 10.0.0.0/24 network will be automatically summarized to 10.0.0.0/8 when crossing the major network of 172.16.0.0/16.
If the routers were instead peering with 10.0.1.0/24 network then the 10.0.0.0/24 network would not be summarized since it is not crossing a major network boundary.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.