IP Routing Features
Configuring OSPF
However, the forwarding software distributes traffic across the three possible
next-hop routes in such a way that all traffic for a specific host is sent to the
same next-hop router.
As shown in Figure 5-24, one possible distribution of traffic to host devices is
as follows:
■ Traffic to host 10.10.0.1 passes through next-hop router 12.0.9.2.
■ Traffic to host 10.10.0.2 passes through next-hop router 13.0.9.3.
■ Traffic to host 10.10.0.3 passes through next-hop router 12.0.9.2.
■ Traffic to host 10.10.0.4 passes through next-hop router 14.0.9.4.
IP Packet Destination Next Hop Used
10.10.0.1 12.0.9.2
10.10.0.2 13.0.9.3
10.10.0.3 12.0.9.2
10.10.0.4 14.0.9.4
Figure 5-24. Example of Traffic Distribution on ECMP Next-Hop Routers
Dynamic OSPF Activation and Configuration
OSPF automatically activates when enabled with router ospf. All configuration
commands affecting OSPF (except reconfiguring the router ID) are dynami-
cally implemented, and can be used without restarting OSPF routing. (To
reconfigure the router ID, refer to “Changing the Router ID” on page 5-15.)
Note OSPF is automatically enabled without a system reset.
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