Once you’re getting ready to pass the BSCI exam and earn your CCNP certification, one of the most important difficulties is Finding out BGP. BGP is completely diverse from any protocol you acquired to receive your CCNA certification, and one of the distinctions is usually that BGP works by using path attributes to favor 1 route over An additional when a number of paths to or from a location exist.
Discover I claimed “to or from”. In previously free of charge BGP tutorials, I talked over the BGP characteristics “fat” and “area preference”. These attributes are accustomed to favor 1 path to a spot about another; for example, if BGP AS 100 has two paths to a destination in AS two hundred, these two characteristics could be established in AS one hundred to favor a single path above another. But Let's say AS a hundred would like to tell the routers in AS two hundred regarding which path it should use to succeed in a provided spot in AS 100?
That’s where the BGP attribute “Multi-Exit Discriminator”, or MED, is available in. The MED price is often set in AS one hundred to inform AS 200 which path it ought to use to reach a offered community in AS 100.
As with many BGP attributes, the MED may be set by using a route-map. What you must watch is that there's no “set med” price in route maps. To change the MED of the path, you might 안전놀이터 want to change the metric of that path. Enable’s say that there http://query.nytimes.com/search/sitesearch/?action=click&contentCollection®ion=TopBar&WT.nav=searchWidget&module=SearchSubmit&pgtype=Homepage#/먹튀검증 are two entry paths for AS two hundred to make use of to reach Places in AS a hundred. You want AS two hundred to make use of the one hundred.one.1.0/24 route in excess of the 100.two.two.0/24 path. Initially, establish the two paths with two different ACLs.
R1(config)#accessibility-record 22 allow 100.1.one.0 0.0.0.255
R1(config)#access-record 23 permit 100.two.2.0 0.0.0.255
Upcoming, generate a route-map that assigns a lower metric to the more-desirable route.
R1(config)#route-map PREFER_PATH permit 10
R1(config-route-map)#match ip address 22
R1(config-route-map)#set metric 100
R1(config-route-map)#route-map PREFER_PATH permit twenty
R1(config-route-map)#match ip handle 23
R1(config-route-map)#set metric 250
At last, use the route-map into the neighbor or neighbors.
R1(config-route-map)#router bgp one hundred
R1(config-router)#neighbor 22.two.two.2 route-map PREFER_PATH out
The important thing points to keep in mind is the fact although numerous BGP characteristics desire a higher benefit, the MED is essentially an external metric – and also a reduce metric is chosen, equally as Along with the protocols you’ve now analyzed to gain your CCNA certification.