H3C Technologies H3C S12500 Series Switches - Manual (Page 276)

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h - history, i - internal, s - suppressed, S - Stale
Origin : i - IGP, e - EGP, ? - incomplete
Network NextHop MED LocPrf PrefVal Path/Ogn
*>i 9.1.1.0/24 10.1.3.1 0 100 0 100i
[SwitchD] display bgp routing-table 9.1.1.0
BGP local router ID : 4.4.4.4
Local AS number : 65001
Paths: 1 available, 1 best
BGP routing table entry information of 9.1.1.0/24:
From : 10.1.3.1 (1.1.1.1)
Relay Nexthop : 0.0.0.0
Original nexthop: 10.1.3.1
AS-path : 100
Origin : igp
Attribute value : MED 0, localpref 100, pref-val 0, pre 255
State : valid, internal, best,
Not advertised to any peers yet
The output indicates the following:
{
Switch F can send route information to Switch B and Switch C through the confederation by
establishing only an EBGP connection with Switch A.
{
Switch B and Switch D are in the same confederation, but belong to different sub-ASs. They
obtain external route information from Switch A and generate the same BGP route entries; it
seems like that they reside in the same AS although they have no direct connection in between.
BGP path selection configuration
Network requirements
• In Figure 93 , all switches run BGP. EBGP runs between Switch A and Switch B, and between Switch
A and Switch C. IBGP runs between Switch B and Switch D, and between Switch D and Switch C.
• OSPF is the IGP protocol in AS 200.
• Configure routing policies, making Switch D use the route 1.0.0.0/8 from Switch C as the optimal.