What is major purpose of default route?

ulviallahverdi

Hello everyone i am preparing for ccent i have studied term default route . I am thinking ablut it about 3days. But i can not understand exact major purpose of default route. Because 0.0.0.0 0.0.0.0 next router ip .
Why we need this default route? Actually i know it is for using stub network that has one exit. Every router has one stub network . Can someone explain it to me. I used default route in my cisco lab. I can use but i do not understand that what does mean defailt route?

hodgey87

Hey,

I guess you could class a default as a gateway of last resort if there isnt a more specifc route in the routing table.

ulviallahverdi

hodgey87 wrote: »

Hey,

I guess you could class a default as a gateway of last resort if there isnt a more specifc route in the routing table.

Thanks, Great explanation. I got it now . But now i want to know that why we use: 0.0.0.0 0.0.0.0?
Because it is security bug when u use this address because, when you set this to router it means router sends packets to everywhere yeah?

nastynate604

That is a great explanation. Essentially a router will broadcast all the routes of the networks that it knows. It will always use the most specific route first with the best metrics. If at the end of the list it still doesn't know where to go, it will use the default route and send the packets there.

rob42

I found this {What is the meaning of the IP address 0.0.0.0} to be a very good explanation of the 0.0.0.0/0 IP Address, but I'm sure there are others out there.

Edited to add… I’ve just seen an even better one {What is the Difference Between 127.0.0.1 and 0.0.0.0?} and funnily enough, it cites the very link that I’ve posted!

hodgey87

ulviallahverdi wrote: »

Thanks, Great explanation. I got it now . But now i want to know that why we use: 0.0.0.0 0.0.0.0?
Because it is security bug when u use this address because, when you set this to router it means router sends packets to everywhere yeah?

Yeah I guess there are security issues with using a default route, but where do we draw the line?! Eventually it will have to be routed through another network and we'll have to trust that their network is secure.

networker050184

Sending packets to the next device isn't really a security concern. You should be securing your devices in other ways.

Hondabuff

ulviallahverdi wrote: »

Hello everyone i am preparing for ccent i have studied term default route . I am thinking ablut it about 3days. But i can not understand exact major purpose of default route. Because 0.0.0.0 0.0.0.0 next router ip .
Why we need this default route? Actually i know it is for using stub network that has one exit. Every router has one stub network . Can someone explain it to me. I used default route in my cisco lab. I can use but i do not understand that what does mean defailt route?

If if you think about the minimal requirements for you computers network card, IP address, subnet mask and gateway. The default works like the gateway function. 0.0.0.0 0.0.0.0 says any IP address on any subnet that's not in the route table, go to this IP address.