If i have R1 which has a LAN behind it and he is connected to R2 that connects to the internet => why is it necessary for R1 to have a static default route to the internet? why cant it have RIP or some other interior routing protocol?
If you have R1 which has a LAN and is connected to R2 you may CHOOSE to have a static default route. But it certainly is NOT required. It is entirely possible to run a dynamic routing protocol (RIP, or OSPF, or EIGRP, etc) and to have R1 learn the default route dynamically.
There is not a single or simple answer about which is better and preferred. What is the better and preferred option will depend on your individual environment and how you establish your criteria for better or preferred. For some the simplicity of a static default route will make that better. For some not consuming any bandwidth on the link between routers with dynamic routing protocol traffic (hello messages, routing updates, etc) will make the static default better. For some being sure that the route to outside is really valid (so you do not waste bandwidth sending packets to the remote router which it will drop because the destination is not reachable) means that a dynamic routing protocol is better.
For many people with just 2 routers the simplicity and lack of overhead traffic will make the static default better. As the network grows in size and complexity the balance tends to shift toward dynamic routing protocol. When the network begins to have multiple paths toward a destination and you want the ability to know if the primary path is no longer useable so that you can shift to the backup path dynamically then the better choice is dynamic routing protocol.
So where in that scale is your particular environment?
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.