H3C Technologies H3C SR8800 - Manual (Page 271)

255
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 information shows that:
{
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 example
Network requirements
• In Figure 96 , all routers run BGP. Between Router A and Router B, and between Router A and Router
C are EBGP connections. Between Router B and Router D, and between Router D and Router C are
IBGP connections.
• 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.
Figure 96 Network diagram
Device Interface IP address Device Interface IP address
Router A GE1/1/1 1.0.0.0/8 Router D POS2/1/1 195.1.1.1/24
POS2/1/1 192.1.1.1/24 POS2/1/2 194.1.1.1/24
POS2/1/2 193.1.1.1/24 Router C POS2/1/1 195.1.1.2/24
Router B POS2/1/1 192.1.1.2/24 POS2/1/2 193.1.1.2/24
POS2/1/2 194.1.1.2/24
Configuration procedure
1. Configure IP addresses for interfaces. (Details not shown)
2. Configure OSPF on routers B, C and D:
# Configure Router B.
<RouterB> system-view
[RouterB] ospf