Concept Guide

To view the conguration, use the show config command in CONFIGURATION COMMUNITY-LIST or CONFIGURATION
EXTCOMMUNITY LIST mode or the show ip {community-lists | extcommunity-list} command in EXEC Privilege mode.
DellEMC#show ip community-lists
ip community-list standard 1
deny 701:20
deny 702:20
deny 703:20
deny 704:20
deny 705:20
deny 14551:20
deny 701:112
deny 702:112
deny 703:112
deny 704:112
deny 705:112
deny 14551:112
deny 701:667
deny 702:667
deny 703:667
deny 704:666
deny 705:666
deny 14551:666
DellEMC#
Congure BGP attributes
Following sections explain how to congure the BGP attributes such as MED, COMMUNITY, WEIGHT, and LOCAL_PREFERENCE.
Changing MED Attributes
By default, Dell EMC Networking OS uses the MULTI_EXIT_DISC or MED attribute when comparing EBGP paths received from dierent
BGP neighbors or peers from the same AS for the same route. You can congure the device to compare the MED attributes from
neighbors or peers in dierent AS using the
bgp always-compare-med command.
To change the usage of MED attribute to choose the best path among the advertised, enter any or all of the following commands.
• Enable MED comparison in the paths from neighbors with dierent 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: Treats a path without a MED value as the most preferred one.
To view the non-default values, use the show config command in CONFIGURATION ROUTER BGP mode.
Manipulating the COMMUNITY Attribute
A COMMUNITY attribute indicates that all the routes with that attribute belong to the same community grouping. In addition to permitting
or denying routes based on the values of the COMMUNITY attributes, you can manipulate the COMMUNITY attribute value and send the
COMMUNITY attribute with the route information.
By default, Dell EMC Networking OS does not send the COMMUNITY attribute to a BGP neighbor or a peer group.
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Border Gateway Protocol (BGP)