What does it mean command ip route 0.0.0.0 0.0.0.0 ؟

Default routes are used to direct packets addressed to networks not explicitly listed in the routing table. Default routes are invaluable in topologies where learning all the more specific networks is not desirable, as in case of stub networks, or not feasible due to limited system resources such as memory and processing power.

This document explains how to configure a default route, or gateway of last resort. These IP commands are used:

This document is not restricted to specific software and hardware versions. The command outputs shown are from the Cisco2500 Series routers running Cisco IOS® Software Release12.2(24a).

The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you are working in a live network, ensure that you understand the potential impact of any command before using it. 

suppose your router is connected to an ISP router you dont know how to reach the ISP router which is unkown destination then we will used this command which is just like an static ip route command but in static we know the destination ip address as well as the next hop ip address. but overhere we dont the destination therefore we used0.0.0.00.0.0.0 which is nothing but default route for unknown destination. this0.0.0.0 contains4.3 billion ip address.

Command for ip default route: ip route0.0.0.00.0.0.0

for static routing: ip route <destination ip address> <destination subnet mask>  <next hop ip address>

It is reffered as "default route" on a router or "gateway of last resort". When a router is not able to search a route in its routing table it forwards the packet to the default route.

simply, this command used always for stub networks as static route.

it means any traffic from any ip with any subnet mask should go from the desired interface which will you determine.

this means you  can route any network with any subnetmask ,this way call " Default Routing "

Default Route

this command used to assign default route when no other route is defined. this also called the quad-zero route.

if the router do not have the dest ip in its routing table it will send that packet throught the interface whch has that command

this sets the default gateway and you should use this command like this:ip route0.0.0.00.0.0.0 (next hop ip address or the exit interface)

ذلك هو الطريق الافتراضي ..فهذا يعني جهاز التوجيه الخاص بك ينظر أولا في جدول التوجيه له لإيجاد مسارا ت لتوجيه الحزم..

إذا كانت الإجابة بنعم فإنه سيتم استخدام المسار، وإلا إذا كان هناك توجيه افتراضي  فإنه سيتم استخدامه ..

هده الكومند تقول للروتر ادا اردت ان تدهب الى اي ريزو بصفة عامة و الادريس ماسك كيف ما كانت ايضا اخرج من هنا مثال الكمند :

ip route0.0.0.00.0.0.0 se0/0/0

او

ip route0.0.0.00.0.0.0 @ip de prochien sous

و هده الكمند تستعمل غالبا ادا ارادت الخروج الى الانترنيت لان الانترنيت تتوفر على عدة ادريسات نحن لا نعرفها