5000 Series Layer 2/3 Managed Data Center Switch CLI Reference Guide
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11-10 bgp aggregate-different-meds
Use the
bgp aggregate-different-meds
command in BGP Router Configuration mode to allow the
aggregation of routes with different MED attributes. By default, BGP only aggregates routes that have the
same MED value, as prescribed by RFC 4271.
When this command is given, the path for an active aggregate address is advertised without a MED
attribute. When this command is not given, if multiple routes match an aggregate address, but have
different MEDs, the aggregate takes the MED of the first matching route. Any other matching prefix with
the same MED is included in the aggregate. Matching prefixes with different MEDs are not considered to
be part of the aggregate and continue to be advertised as individual routes.
Use the
no
command in BGP Router Configuration mode to return the command to the default.
bgp aggregate-different-meds
no bgp aggregate-different-meds
Parameters
None.
Default
The default is a matching MED val for all routes aggregated by a given aggregate address.
Command Mode
•
BGP Router Config
•
IPv6 Address Family Config
•
IPv4 VRF Address Family Config
11-11 bgp always-compare-med
To compare MED values during the decision process in paths received from different ASs, use the
bgp
always-compare-med
command. The MED is a 32-bit integer, commonly set by an external peer to
indicate the internal distance to a destination. The decision process compares MED values to prefer
paths that have a shorter internal distance. Since different ASs may use different internal distance metrics
or have different policies for setting the MED, the decision process normally does not compare MED
values in paths received from peers in different autonomous systems. This command allows you to force
BGP to compare MEDs, regardless of whether paths are received from a common AS.
Use the
no
command to revert to the default behavior, only comparing MED values from paths received
from neighbors in the same AS.
bgp always-compare-med
no bgp always-compare-med