Original subtitles

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There are 2 main ways that routes get added to the routing tables or routers.

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The first way to use static routes

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where an administrator manually adds a route to the routing table

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and the second way is to use dynamic routing protocols.

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So with static routes, you as the administrator are adding the routes to the routing table.

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The advantage of this method is that there is no overhead

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on the network, in that, they are no keepalives

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or constant routing updates sent between routers.

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RIP or Routing Information Protocol which is an older routing protocol

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sends it entire routing table every 30 seconds.

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So when using static routes rather than RIP that overhead is removed.

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More modern routing protocols such as EIGRP and OSPF

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remove this constant updating that took place in RIP every 30 seconds

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but they still send hello's and keepalives

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on the network which consumes bandwidth.

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With static routes that is removed

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but the major disadvantage of static routes is that you as the administrator

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have to update the routing table

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which could be a lot of work if you have a large network.

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Static routes do not automatically taken to account changes in the network

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you as the administrator would have to manually update

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the routing table on a router or multiple routers if a link went down

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so the overhead is not on the network

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the overhead is on you as the administrator to keep everything updated.

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Static routes do not scale when networks become large.

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The amount of work involved in keeping routing tables updated manually is just too great

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especially when there are lots of topology changes.

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Static routes do not update routing tables

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when topology changes in most cases.

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Now that being said, it is possible these days to monitor IP addresses

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and for example to remove a route from the routing table

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if an IP address is no longer available.

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So it's possible to implement some dynamic options with static routes

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but the overhead is still large and static routes are cumbersome in large networks.

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Now static route are still used in lot of networks today

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the most common example is a default static route

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your home a DSL or cable or fiber router

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will typically have a default route to your service provider.

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So your home router doesn’t know about the routes on the Internet

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it's simply forwards the traffic to your ISP

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a default route in a router's routing table basically tells the router

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when you don’t have a specific network for traffic

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that you receive in your routing table simply send the packets to the router

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that’s configured as your default gateway or gateway of last resort.

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So when you configure a default route on a router

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you are pointing it to another router

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which means that router will simply send that traffic to that default gateway

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when it doesn’t have a more specific route in the routing table.