Dell S4048T, Configuration Manual

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Weight
The weight attribute is local to the router and is not advertised to neighboring routers.
If the router learns about more than one route to the same destination, the route with the highest weight is
preferred. The route with the highest weight is installed in the IP routing table.
Local Preference
Local preference (LOCAL_PREF) represents the degree of preference within the entire AS. The higher the
number, the greater the preference for the route.
Local preference (LOCAL_PREF) is one of the criteria used to determine the best path, so keep in mind that
other criteria may impact selection, as shown in the illustration in
Best Path Selection Criteria . For this
example, assume that thelocal preference (LOCAL_PREF) is the only attribute applied. In the following
illustration, AS100 has two possible paths to AS 200. Although the path through Router A is shorter (one hop
instead of two), the LOCAL_PREF settings have the preferred path go through Router B and AS300. This is
advertised to all routers within AS100, causing all BGP speakers to prefer the path through Router B.
Figure 26. BGP Local Preference
Border Gateway Protocol IPv4 (BGPv4) 215