Users Guide

MED attributes
OS10 uses the MULTI_EXIT_DISC or MED attribute when comparing EBGP paths from the same AS. MED comparison is not
performed in paths from neighbors with different AS numbers.
1. Enable MED comparison in the paths from neighbors with different AS in ROUTER-BGP mode.
always-compare-med
2. Change the best path MED selection in ROUTER-BGP mode.
bestpath med {confed | missing-as-best}
● confed—Selects the best path MED comparison of paths learned from BGP confederations.
● missing-as-best—Treats a path missing an MED as the most preferred one.
● missing-as-worst—Treats a path missing an MED as the least preferred one.
Modify MED attributes
OS10(config)# router bgp 100
OS10(conf-router-bgp-100)# always-compare-med
OS10(conf-router-bgp-100)# bestpath med confed
Local preference attribute
You can change the value of the LOCAL_PREFERENCE attributes for all routes the router receives. To change the
LOCAL_PREF value in ROUTER-BGP mode from 0 to 4294967295 with default 100, use the default local preference
value command.
To view the BGP configuration, use the show running-configuration command. A more flexible method for manipulating
the LOCAL_PREF attribute value is to use a route-map.
1. Assign a name to a route map in CONFIGURATION mode.
route-map map-name {permit | deny | sequence-number}
2. Change the LOCAL_PREF value for routes meeting the criteria of this route map in ROUTE-MAP mode, then return to
CONFIGURATION mode.
set local-preference value
exit
3. Enter ROUTER-BGP mode.
router bgp as-number
4. Enter the neighbor to apply the route map configuration in ROUTER-BGP mode.
neighbor {ip-address}
5. Apply the route map to the neighbor’s incoming or outgoing routes in ROUTER-BGP-NEIGHBOR-AF mode.
route-map map-name {in | out)
6. Enter the peer group to apply the route map configuration in ROUTER-BGP mode.
template template-name
7. Apply the route map to the peer group’s incoming or outgoing routes in CONFIG-ROUTER-TEMPLATE-AF mode.
route-map map-name {in | out}
Configure and view local preference attribute
OS10(config)# route-map bgproutemap 1
OS10(conf-route-map)# set local-preference 500
Layer 3
637