HP 6125G Configuration Manual page 132

NEXT_HOP
•
Different from IGP, the NEXT_HOP attribute may not be the IP address of a directly connected
router. It involves the following types of values, as shown in
When advertising a self-originated route to an EBGP peer, a BGP speaker sets the NEXT_HOP
for the route to the address of its sending interface.
When sending a received route to an EBGP peer, a BGP speaker sets the NEXT_HOP for the
route to the address of the sending interface.
When sending a route received from an EBGP peer to an IBGP peer, a BGP speaker does not
modify the NEXT_HOP attribute. If load-balancing is configured, the NEXT_HOP attribute of
the equal-cost routes is modified. For load-balancing information, see
Figure 49 NEXT_HOP attribute
MED (MULTI_EXIT_DISC)
•
The MED attribute is exchanged between two neighboring ASs, each of which does not advertise
the attribute to any other AS.
Similar to metrics used by IGP, MED is used to determine the best route for traffic going into an AS.
When a BGP router obtains multiple routes to the same destination, but with different next hops, it
considers the route with the smallest MED value the best route given that other conditions are the
same. As shown in
according to MED.
Figure 50 MED attribute
Figure 50, traffic from AS10 to AS20 travels through Router B that is selected
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Figure 49.
"BGP route selection."