Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.100.0 - Page 194

*>i 6.133.0.0/21 *>i 6.151.0.0/16 --More-- 205.171.0.16 205.171.0.16 100 0 100 0 209 7170 1455 i 209 7170 1455 i Changing MED Attributes By default, Dell Networking OS uses the MULTI_EXIT_DISC or MED attribute when comparing EBGP paths from the same AS. To change how the MED attribute is used, enter any or all of the following commands. • Enable MED comparison in the paths from neighbors with different ASs. CONFIG-ROUTER-BGP mode bgp always-compare-med By default, this comparison is not performed. • Change the bestpath MED selection. CONFIG-ROUTER-BGP mode bgp bestpath med {confed | missing-as-best} • confed: Chooses the bestpath MED comparison of paths learned from BGP confederations. • missing-as-best: Treat a path missing an MED as the most preferred one. To view the nondefault values, use the show config command in CONFIGURATION ROUTER BGP mode. Changing the LOCAL_PREFERENCE Attribute In Dell Networking OS, you can change the value of the LOCAL_PREFERENCE attribute. To change the default values of this attribute for all routes received by the router, use the following command. • Change the LOCAL_PREF value. CONFIG-ROUTER-BGP mode bgp default local-preference value • value: the range is from 0 to 4294967295. The default is 100. To view the BGP configuration, use the show config command in CONFIGURATION ROUTER BGP mode or the show runningconfig bgp command in EXEC Privilege mode. A more flexible method for manipulating the LOCAL_PREF attribute value is to use a route map. 1 Enter the ROUTE-MAP mode and assign a name to a route map. CONFIGURATION mode route-map map-name [permit | deny] [sequence-number] 2 Change LOCAL_PREF value for routes meeting the criteria of this route map. CONFIG-ROUTE-MAP mode set local-preference value 3 Return to CONFIGURATION mode. CONFIG-ROUTE-MAP mode exit 194 Border Gateway Protocol IPv4 (BGPv4)