reduce the options. If a number of best paths is determined, this selection criteria is applied to group’s best to determine the ultimatebest path.In non-deterministic mode (the bgp non-deterministic-med command is applied), paths are compared in the order in whichthey arrive. This method can lead to Dell Networking OS choosing different best paths from a set of paths, depending on the order inwhich they were received from the neighbors because MED may or may not get compared between the adjacent paths. Indeterministic mode, Dell Networking OS compares MED between the adjacent paths within an AS group because all paths in the ASgroup are from the same AS.NOTE: The bgp bestpath as-path multipath-relax command is disabled by default, preventing BGP fromload-balancing a learned route across two or more eBGP peers. To enable load-balancing across different eBGP peers,enable the bgp bestpath as-path multipath-relax command. A system error results if you configure the bgpbestpath as-path ignore command and the bgp bestpath as-path multipath-relax command at thesame time. Only enable one command at a time.The following illustration shows that the decisions BGP goes through to select the best path. The list following the illustration detailsthe path selection criteria.Figure 25. BGP Best Path SelectionBest Path Selection Details1. Prefer the path with the largest WEIGHT attribute.2. Prefer the path with the largest LOCAL_PREF attribute.3. Prefer the path that was locally Originated via a network command, redistribute command or aggregate-address command.a. Routes originated with the Originated via a network or redistribute commands are preferred over routesoriginated with the aggregate-address command.4. Prefer the path with the shortest AS_PATH (unless the bgp bestpath as-path ignore command is configured, thenAS_PATH is not considered). The following criteria apply:a. An AS_SET has a path length of 1, no matter how many ASs are in the set.174 Border Gateway Protocol IPv4 (BGPv4)
