CCNA Routing & Switching:Default routing скачать в хорошем качестве

CCNA Routing & Switching:Default routing

As you may know, Cisco routers will match traffic to a destination based on the closest match found in the routing table. With that being said; if the router has two routes in the routing table, one for 10.88.21.0/28 and one for 10.88.21.0/24 and the router receives traffic destined towards the host 10.88.21.6 then the router will choose the 10.88.21.0/28 route as its a closer match In the previous two labs you learned about static routing and floating static routes, you are going to continue to build upon that foundation with configuring a default static route; commonly referred to as a “default route”. As a CCNA you must understand the concept of the default route on a Cisco router and how to configure them. It is common that a router will have a floating default route in production in case the dynamic routing protocol fails for whatever reason, the floating default route would be injected into the routing table and eliminate downtime if designed and implemented properly. In a network there are commonly two ways to get to the internet from within the network. You can have a default route on your WAN edge router pointing towards the ISP so that if any traffic destined towards a network is not found in the routing table of your WAN edge router then it would be passed onto the ISP. The other possibility is to have a WAN edge router participate in BGP (Boarder Gateway Protocol) which is the protocol that the internet is built upon. Having a full internet routing table via BGP will give you the ability to have every route on the internet on a single router. However BGP does not fall within the scope of the CCNA level material so we’ll only be focusing on a default route. If you are interested in how the internet works and curious about BGP then you’ll have to continue your studies on to the CCNP after you’ve completed the CCNA. Configuring a Default Route is as simple as configuring a static route. A default route is represented by 0.0.0.0/0. If you take a second and analyze the network and subnet you’ll realize that any ip address can fall in this subnet from 0.0.0.0 to 255.255.255.255. In this lab you will use the same topology that you’re worked with in the previous Lab 6-2 however the IP Addressing has been updated to reflect the lab number. You will be removing the static routes previously assigned to R3 and configuring a default route on R3 to point towards R2. Familiarize yourself with the following new command(s); Command Description ip route 0.0.0.0 0.0.0.0 nh.nh.nh.nh # When specifying a static route to 0.0.0.0/0 you are effectively configuring a default route, a route that will catch all traffic if no other route exist for the traffic destination in the routing table. Lab Prerequisites If you are using GNS3 than load the Free CCNA Workbook GNS3 topology than start devices; R1, R2 and R3. Establish a console session with devices R1, R2 and R3 than load the initial configurations provided below by copying the config from the textbox and pasting it into the respected routers console. Lab Objectives