Configuring the next hop attribute – H3C Technologies H3C S7500E Series Switches User Manual
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Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 10.0.0.0 3.3.3.3 50 0 200e
* i 10.0.0.0 2.2.2.2 50 0 300e
* i 1.1.1.1 60 0 200e
Note that, in this case, BGP load balancing cannot be implemented because load balanced routes
must have the same AS-path attribute.
Follow these steps to enable the comparison of MED of routes from each AS:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—
Enable the comparison of MED of routes
from each AS
bestroute compare-med
Optional
Not enabled by default
Enable the comparison of MED of routes from confederation peers
Follow these steps to enable the comparison of MED of routes from confederation peers:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter BGP view
bgp as-number
—
Enable the comparison of MED of routes
from confederation peers
bestroute med-confederation
Optional
Not enabled by default
The MED attributes of routes from confederation peers are not compared if their AS-path attributes
contain AS numbers that don’t belong to the confederation. For example, there are three routes:
AS-path attributes of them are 65006 65009, 65007 65009 and 65008 65009, and MED values of them
are 2, 3, and 1. Because the third route contains an AS number that does not belong to the
confederation, the first route becomes the optimal route.
Configuring the Next Hop Attribute
By default, when advertising routes to an iBGP peer/peer group, a BGP router does not set itself as the
next hop. However, to ensure a BGP peer can find the correct next hop in some cases, you need to
configure the router as the next hop for routes sent to the peer.
For example, as shown in the figure below, Router A and Router B establish an eBGP neighbor
relationship, and Router B and Router C establish an iBGP neighbor relationship. When Router B
advertises a network learned from Router A to Router C, if Router C has no route to IP address