Specifications

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Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, Release 5.0(3)U2(2)
OL-25782-02
Chapter 6 Configuring Advanced BGP
Configuring Advanced BGP
Command Purpose
bestpath [always-compare-med |
compare-routerid | med {missing-as-worst |
non-deterministic}| as-path
multipath-relax]
Example:
switch(config-router)# bestpath
always-compare-med
switch(config-router)# bestpath as-path
multipath-relax
Modifies the best-path algorithm. The optional
parameters are as follows:
• always-compare-med—Compares MED on
paths from different autonomous systems.
• compare-routerid—Compares the router IDs
for identical eBGP paths.
• med missing-as-worst—Treats a missing
MED as the highest MED.
• med non-deterministic—Does not always
pick the best MED path from among the paths
from the same autonomous system.
• as-path multipath-relax—Beginning with
Cisco NX-OS Release 5.0(3)U1(2), allows the
switch to treat paths received from different
AS’s for multipath, if their AS-path lengths are
the same and other multipath conditions are
met.
enforce-first-as
Example:
switch(config-router)# enforce-first-as
Enforces the neighbor autonomous system to be the
first AS number listed in the AS_path attribute for
eBGP.
log-neighbor-changes
Example:
switch(config-router)#
log-neighbor-changes
Generates a system message when a neighbor
changes state.
router-id id
Example:
switch(config-router)# router-id
209.165.20.1
Manually configures the router ID for this BGP
speaker.
timers [bestpath-delay delay | bgp
keepalive holdtime | prefix-peer-timeout
timeout]
Example:
switch(config-router)# timers bgp 90 270
Sets the BGP timer values. The optional parameters
are as follows:
• delay—Initial best-path timeout value after a
restart. The range is from 0 to 3600 seconds.
The default value is 300.
• keepalive—BGP session keepalive time. The
range is from 0 to 3600 seconds. The default
value is 60.
• holdtime—BGP session hold time.The range is
from 0 to 3600 seconds. The default value is
180.
• timeout—Prefix peer timeout value. The range
is from 0 to 1200 seconds. The default value is
30.
You must manually reset the BGP sessions after
configuring this command.