Foundry Networks FESX - Page 388

Foundry Configuration Guide for the FESX, FSX, and FWSX
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Figure 16.3 Standard and null static routes to the same destination network
Figure 16.4 shows another example of two static routes. In this example, a standard static route and an interface-
based static route are configured for destination network 192.168.6.0/24. The interface-based static route has a
lower metric than the standard static route. As a result, the Layer 3 Switch always prefers the interface-based
route when the route is available. However, if the interface-based route becomes unavailable, the Layer 3 Switch
still forwards the traffic toward the destination using an alternate route through gateway 192.168.8.11/24.
192.168.7.69/24
X
192.168.6.157/24
192.168.7.7/24
192.168.6.188/24
192.168.7.69/24
192.168.6.157/24
192.168.7.7/24
192.168.6.188/24
Two static routes to 192.168.7.0/24:
--Standard static route through
gateway 192.168.6.157, with metric 1
--Null route, with metric 2
When standard static route
is good, Router A uses that
route.
If standard static route is
unavailable, Router A uses
the null route (in effect dropping
instead of forwarding the packets).
Null
Router A
Router B
Router A
Router B