D-Link DXS-3600-EM-8T CLI Guide - Page 77

DXS-3600 Series 10GbE Layer 2/3 Switch CLI Reference Guide 7-7 bgp bestpath as-path ignore This command is used to not consider the as-path factor in selection of the best path. Use the no form of this command to restore default behavior and configure BGP to consider the AS-path during route selection. bgp bestpath as-path ignore no bgp bestpath as-path ignore Parameters Default Command Mode Command Default Level Usage Guideline None. AS path is considered when the best path selects. Router Configuration. Level: 8. (EI Mode Only Command) The following are the best path selection rules. • If the next hop associated with the route is unreachable, then the route is dropped. • Then route with the largest weight is selected. • If weight cannot determine, then the largest LOCAL-PREF is used to determine the preferred route. • If still cannot determine the preferred route, then the route with the shortest AS- PATH list is preferred. • If still cannot determine the preferred route, then lowest origin type is preferred. • If still cannot determine the preferred route, then the lowest MED is preferred. • If still cannot determine the preferred route, eBGP is preferred over iBGP paths. • Prefer the path with the lowest IGP metric to the BGP next hop. • Determine if multiple paths require installation in the routing table for BGP Multipath. • When both paths are external, prefer the path that was received first (the oldest one). • Prefer the route that comes from the BGP router with the lowest router ID. • If the originator or router ID is the same for multiple paths, prefer the path with the minimum cluster list length. • Prefer the path that comes from the lowest neighbor address. You can use the commands, bgp bestpath as-path ignore, bgp bestpath compare-router-id or bgp default local-preference to customize the path selection process. You can verify your settings by entering show ip bgp parameters command. Example This example shows how to configure the switch to ignore the AS-PATH for the best path for the autonomous system 65534. DXS-3600-32S#configure terminal DXS-3600-32S(config)#router bgp 65534 DXS-3600-32S(config-router)#bgp bestpath as-path ignore DXS-3600-32S(config-router)# 7-8 bgp bestpath compare-confed-aspath This command is used to configure a BGP routing process to compare the confederation AS path length of the routes received. To return the BGP routing process to the default operation, use the no form of this command. bgp bestpath compare-confed-aspath no bgp bestpath compare-confed-aspath Parameters Default Command Mode Command Default Level None. By default, this option is disabled. Router Configuration. Level: 8. (EI Mode Only Command) 69