If you’re getting ready to move the BSCI exam and make your CCNP certification, among the greatest difficulties is Understanding BGP. BGP is completely unique from any protocol you discovered to generate your CCNA certification, and among the list of dissimilarities is usually that BGP makes use of path characteristics to favor one particular path in excess of Yet another when numerous paths to or from a location exist.
Notice I said “to or from”. In previously free BGP tutorials, I discussed the BGP characteristics “fat” and “neighborhood desire”. These attributes are utilized to favor a person path into a desired destination in excess of An additional; as an example, if BGP AS 100 has two paths into a desired destination in AS 200, these two attributes is usually established in AS a hundred to favor one path over another. But Let's say AS a hundred wishes to inform the routers in AS 200 regarding which path it need to use to succeed in a presented destination in AS 사설토토 a hundred?
That’s the place the BGP attribute “Multi-Exit Discriminator”, or MED, is available in. The MED price is usually set in AS a hundred to inform AS 200 which route it ought to use to succeed in a offered community https://en.wikipedia.org/wiki/?search=토토사이트 in AS a hundred.
As with many BGP attributes, the MED can be established having a route-map. What you'll want to view is that there's no “established med” value in route maps. To change the MED of the route, you might want to alter the metric of that path. Enable’s say there are two entry paths for AS two hundred to utilize to reach destinations in AS 100. You need AS 200 to utilize the a hundred.1.1.0/24 path about the a hundred.2.two.0/24 path. 1st, detect the two paths with two different ACLs.
R1(config)#access-checklist 22 permit one hundred.one.1.0 0.0.0.255
R1(config)#access-record 23 permit 100.2.2.0 0.0.0.255
Up coming, write a route-map that assigns a reduced metric to the greater-fascinating path.
R1(config)#route-map PREFER_PATH allow 10
R1(config-route-map)#match ip deal with 22
R1(config-route-map)#set metric 100
R1(config-route-map)#route-map PREFER_PATH permit twenty
R1(config-route-map)#match ip tackle 23
R1(config-route-map)#set metric 250
Lastly, apply the route-map on the neighbor or neighbors.
R1(config-route-map)#router bgp one hundred
R1(config-router)#neighbor 22.2.two.2 route-map PREFER_PATH out
The important thing points to remember is the fact whilst many BGP attributes like a higher value, the MED is basically an exterior metric – as well as a decrease metric is most popular, equally as Together with the protocols you’ve presently studied to get paid your CCNA certification.
