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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 42 Configuring IP Unicast Routing Configuring BGP
Beginning in privileged EXEC mode, follow these steps to configure some decision attributes:
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 router bgp autonomous-system Enable a BGP routing process, assign it an AS number,
and enter router configuration mode.
Step 3 bgp best-path as-path ignore (Optional) Configure the router to ignore AS path length
in selecting a route.
Step 4 neighbor {ip-address | peer-group-name} next-hop-self (Optional) Disable next-hop processing on BGP updates
to a neighbor by entering a specific IP address to be used
instead of the next-hop address.
Step 5 neighbor {ip-address | peer-group-name} weight
weight (Optional) Assign a weight to a neighbor connection.
Acceptable values are from 0 to 65535; the largest weight
is the preferred route. Routes learned through another
BGP peer have a default weight of 0; routes sourced by the
local router have a default weight of 32768.
Step 6 default-metric number (Optional) Set a MED metric to set preferred paths to
external neighbors. All routes without a MED will also be
set to this value. The range is 1 to 4294967295. The lowest
value is the most desirable.
Step 7 bgp bestpath med missing-as-worst (Optional) Configure the switch to consider a missing
MED as having a value of infinity, making the path
without a MED value the least desirable path.
Step 8 bgp always-compare med (Optional) Configure the switch to compare MEDs for
paths from neighbors in different autonomous systems. By
default, MED comparison is only done among paths in the
same AS.
Step 9 bgp bestpath med confed (Optional) Configure the switch to consider the MED in
choosing a path from among those advertised by different
subautonomous systems within a confederation.
Step 10 bgp deterministic med (Optional) Configure the switch to consider the MED
variable when choosing among routes advertised by
different peers in the same AS.
Step 11 bgp default local-preference value (Optional) Change the default local preference value. The
range is 0 to 4294967295; the default value is 100. The
highest local preference value is preferred.
Step 12 maximum-paths number (Optional) Configure the number of paths to be added to
the IP routing table. The default is to only enter the best
path in the routing table. The range is from 1 to 16. Having
multiple paths allows load-balancing among the paths.
(Although the switch software allows a maximum of
32 equal-cost routes, the switch hardware will never use
more than 16 paths per route.)
Step 13 end Return to privileged EXEC mode.