If you’re preparing to move the BSCI Test and receive your CCNP certification, certainly one of the greatest challenges is Mastering BGP. BGP is completely distinct from 토토사이트 any protocol http://www.thefreedictionary.com/토토사이트 you learned to get paid your CCNA certification, and among the dissimilarities is always that BGP uses route characteristics to favor 1 path in excess of A different when multiple paths to or from a location exist.
Discover I said “to or from”. In before cost-free BGP tutorials, I discussed the BGP characteristics “fat” and “local choice”. These attributes are used to favor a person route to the spot over One more; as an example, if BGP AS one hundred has two paths to your vacation spot in AS two hundred, these two attributes might be set in AS one hundred to favor one particular route around An additional. But Let's say AS a hundred desires to inform the routers in AS 200 as to which path it need to use to succeed in a provided place in AS one hundred?
That’s wherever the BGP attribute “Multi-Exit Discriminator”, or MED, comes in. The MED value may be established in AS one hundred to tell AS 200 which path it need to use to reach a specified network in AS 100.
Just like lots of BGP characteristics, the MED can be set having a route-map. What you must enjoy is that there's no “set med” worth in route maps. To alter the MED of a route, you should alter the metric of that route. Allow’s say there are two entry paths for AS 200 to make use of to succeed in Locations in AS 100. You need AS two hundred to make use of the a hundred.1.one.0/24 path above the one hundred.2.two.0/24 path. To start with, discover the two paths with two independent ACLs.
R1(config)#access-record 22 allow 100.one.1.0 0.0.0.255
R1(config)#accessibility-checklist 23 allow one hundred.two.two.0 0.0.0.255
Subsequent, compose a route-map that assigns a decreased metric to the greater-fascinating path.
R1(config)#route-map PREFER_PATH allow 10
R1(config-route-map)#match ip tackle 22
R1(config-route-map)#established metric a hundred
R1(config-route-map)#route-map PREFER_PATH allow twenty
R1(config-route-map)#match ip handle 23
R1(config-route-map)#set metric 250
At last, apply the route-map to the neighbor or neighbors.
R1(config-route-map)#router bgp a hundred
R1(config-router)#neighbor 22.2.two.2 route-map PREFER_PATH out
The key factors to remember is the fact that whilst several BGP attributes favor a greater price, the MED is basically an external metric – and a reduce metric is chosen, equally as Together with the protocols you’ve previously examined to earn your CCNA certification.