Selecting The Best Path - Juniper BGP - CONFIGURATION GUIDE V 11.1.X Configuration Manual

JUNOSe 11.1.x BGP and MPLS Configuration Guide
test ip bgp neighbor
NOTE: If you test the current policies, the results might vary for routes learned before
the current policies were activated if you did not clear the forwarding table when
the policies changed.

Selecting the Best Path

BGP selects only one route to a destination as the best path. When multiple routes
to a given destination exist, BGP must determine which of these routes is the best.
BGP puts the best path in its routing table and advertises that path to its BGP
neighbors.
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Selecting the Best Path
Use to test the effect of BGP policies on a router without implementing the policy.
You can apply the test to routes advertised to peers or received from peers.
You can test the following kinds of policies: distribute lists, filter lists, prefix lists,
prefix trees, or route maps. If you do not specify a policy, then the test uses
whatever policies are currently in effect on the router.
The following three items apply to the test ip bgp neighbor command only:
The address-family identifier for the route is the same as is used for identifying
the neighbor.
If you do not specify a route, the test is performed for all routes associated
with the address-family identifier.
Specifying only an address and mask without a route distinguisher causes
all routes sharing the address and mask to be considered. Specifying only
an address causes a best match to be performed for the route.
If you completely specify a route with IP address, mask, and route distinguisher,
the command displays detailed route information. Otherwise only summary
information is shown. Use the fields option to select particular fields of interest.
If you specify a BGP peer group by using the peerGroupName argument, all the
members of the peer group inherit the characteristic configured with this
command unless it is overridden for a specific peer.
You can set a weight value for inbound routes filtered with a filter list.
Example
host1#test ip bgp neighbor 10.12.54.21 advertised-routes distribute-list boston5
fields
There is no no version.
See test bgp ipv6 neighbor.
See test ip bgp neighbor.