Chapter 19: Ip Unicast Routing; Overview Of Ip Unicast Routing; Router Interfaces - Extreme Networks ExtremeWare XOS Guide Manual

19 IP Unicast Routing
This chapter describes the following topics:
Overview of IP Unicast Routing on page 365
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Proxy ARP on page 368
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Relative Route Priorities on page 369
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Configuring IP Unicast Routing on page 370
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Verifying the IP Unicast Routing Configuration on page 370
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Routing Configuration Example on page 370
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IP Multinetting on page 372
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Configuring DHCP/BOOTP Relay on page 378
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This chapter assumes that you are already familiar with IP unicast routing. If not, refer to the following
publications for additional information:
RFC 1256—ICMP Router Discovery Messages
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RFC 1812—Requirements for IP Version 4 Routers
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NOTE
For more information on interior gateway protocols, see
see Chapter 21.

Overview of IP Unicast Routing

The switch provides full Layer 3, IP unicast routing. It exchanges routing information with other routers
on the network using either the Routing Information Protocol (RIP) or the Open Shortest Path First
(OSPF) protocol. The switch dynamically builds and maintains a routing table and determines the best
path for each of its routes.
Each host using the IP unicast routing functionality of the switch must have a unique IP address
assigned. In addition, the default gateway assigned to the host must be the IP address of the router
interface.

Router Interfaces

The routing software and hardware routes IP traffic between router interfaces. A router interface is
simply a virtual LAN (VLAN) that has an IP address assigned to it.
As you create VLANs with IP addresses belonging to different IP subnets, you can also choose to route
between the VLANs. Both the VLAN switching and IP routing function occur within the switch.
ExtremeWare XOS 11.1 Concepts Guide
Chapter 20. For information on exterior gateway protocols,
365