When you’re preparing to move the BSCI Examination and generate your CCNP certification, among the biggest issues is Understanding BGP. BGP is totally various from any protocol you realized to make your CCNA certification, and one of many discrepancies is that BGP employs path characteristics to favor one path about An additional when various paths to or from the place exist.
Observe I explained “to or from”. In before cost-free BGP tutorials, I talked over the BGP characteristics “pounds” and “area preference”. These characteristics are used to favor a single route into a spot around another; one example is, if BGP AS a hundred has two paths to the location in AS two hundred, these two attributes may be established in AS a hundred to favor 1 route above A different. But Let's say AS a hundred would like to tell the routers in AS two hundred concerning which route it must use to achieve a presented vacation spot in AS one hundred?
That’s where by the BGP attribute “Multi-Exit Discriminator”, or MED, is available in. The MED value is often set in AS one hundred to tell AS two hundred which route it should use to succeed in a provided community in AS 100.
As with several BGP attributes, the MED is often established using a route-map. What you must watch is that there's no “established med” benefit in route maps. To alter the MED of a path, you should change the metric of that path. Allow’s say there are two entry paths for AS two hundred to utilize to achieve destinations in AS a hundred. You wish AS two hundred to use the a hundred.1.1.0/24 path more than the 100.2.2.0/24 path. First, establish the two paths with two separate ACLs.
R1(config)#obtain-record 22 permit one hundred.one.1.0 0.0.0.255
R1(config)#entry-list 23 permit 100.two.2.0 0.0.0.255
Following, write a route-map that assigns a decreased metric to the greater-desirable route.
R1(config)#route-map PREFER_PATH permit ten
R1(config-route-map)#match ip address 22
R1(config-route-map)#established metric a hundred
R1(config-route-map)#route-map PREFER_PATH permit 20
R1(config-route-map)#match ip tackle 23
R1(config-route-map)#established metric 250
Eventually, apply the route-map into the neighbor or neighbors.
R1(config-route-map)#router bgp 100
R1(config-router)#neighbor 22.2.2.two route-map PREFER_PATH out
The main element details to keep in mind is always that though numerous BGP attributes like an increased value, the https://en.search.wordpress.com/?src=organic&q=토토사이트 MED is essentially an exterior metric – and also a lower metric is desired, 토토사이트 just as with the protocols you’ve presently analyzed to make your CCNA certification.