R3303-HP HSR6800 Routers Layer 3 - IP Routing Configuration Guide

264
Total Number of Routes: 1
BGP Local router ID is 4.4.4.4
Status codes: * - valid, ^ - VPNv4 best, > - best, d - damped,
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
[RouterD] 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:
{ Router F can send route information to Router B and Router C through the confederation by
establishing only an EBGP connection with Router A.
{ Router B and Router D are in the same confederation, but belong to different sub ASs. They
obtain external route information from Router 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 80, all routers run BGP. EBGP runs between Router A and Router B, and between Router
A and Router C. IBGP runs between Router B and Router D, and between Router D and Router C.
• OSPF is the IGP protocol in AS 200.
• Configure routing policies to make Router D give priority to the route 1.0.0.0/8 learned from Router
C.