3Com 3500 - page 425

ip route default 425
✓ 3500
✓ 9000
✓ 9400
✓ 3900
✓ 9300
ip route default For CoreBuilder 9000: Applies to Layer 3 switching modules only.
Adds a default route to the routing table immediate ly.
Valid Minimum Abbreviation
ip route de
Important Considerations
■If you define a default route, the system uses it to forw ard packets
that do not match any other routing table entry. The system can learn
a route through the routing protocol, or you can statically configure a
default route.
■The system can learn a default route.
■If the routing table does not contain a default route, the sy stem
cannot forward a packet that does not match any other routing table
entry. When the system drops the packet, it sends an Internet Control
Message Protocol (ICMP) destination unreachable message to the
host that sent the packet.
■On the CoreBuilder 3500 or the CoreBuilder 9 000 Layer 3 module,
you establish a static sink default route, so that the system can
advertise itself as a default router. The static sink default route is not
used in any of the system’s forwarding decisions because it does not
have a valid next-hop gateway, but it can be advertised to all of the
system’s neighbors (unless you establish IP policies to prevent the
advertisement).
Defining a static sink default route causes the route to b e advertised
through any IP protocols that you have configured on t he system (for
example, Open Shortest Path First (OSPF) and RIP). For more
information about static sink default routes, see the Implementation
Guide for the CoreBui lder 3500 or for the C oreBuilder 9000.
Options
Prompt Description Possible Values [Default]
Gateway IP
address
IP address of the
route that you want
to add as the default
■A valid IP address
■0.0.0.0 (static sink
default route)
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