Zhone Technologies 900 ユーザーズマニュアル

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8-6 
Server Cards
Model No.
Running Head
IPR WAN Routing
IPR Card
8.4
IPR WAN Routing
IPR is designed to provide a maximum level of flexibility to users with different IP WAN 
topology requirements. IPR supports hub-and-spoke topology, partially or fully meshed 
topology, point-to-point IP interfaces, multi-point IP interface, unnumbered IP interfaces or a 
combination of any of the above. Figure 8-4 shows the Hub-to-Spoke Topology.
8.4.1
Hub-and-Spoke
The Hub-and-Spoke topology is that every “regional” (spoke) router has to go through the 
same “central-office: (hub) router for every destination IP node that is not local to a spoke 
router. This topology is very simple to configure: All spoke routers have a hub router as their 
default gateway (Default gateway is a router that IP nodes go to if they do not know a path to 
a particular IP network). Hub can be completely passive (from a routing protocol point of 
view), advertising no routes to spoke router, and the spoke router can be configured with 
default point at the hub. A spoke router, in its turn, will advertise any locally known or 
discovered IP networks (if any) through any routing protocol, since routing convergence time 
is irrelevant. IPR can be both a spoke and/or a hub router.
Figure 8-4. Hub-and-Spoke Topology
"Spoke" Router
Central Side
"Hub" Router
"Spoke" Router
"Spoke" Router
"Spoke" Router