Information About Configuring Ip Unicast Routing - Cisco Catalyst 9500 series Configuration Manual

Information About Configuring IP Unicast Routing

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Information About Configuring IP Unicast Routing
This module describes how to configure IP Version 4 (IPv4) unicast routing on the switch.
A switch stack operates and appears as a single router to the rest of the routers in the network. Basic routing
functions like static routing and the Routing Information Protocol (RIP), are available with both the Network
Essentials license and the Network Advantage license. To use advanced routing features and other routing
protocols, you must have the Network Advantage license enabled on the standalone switch or on the active
switch.
In addition to IPv4 traffic, you can also enable IP Version 6 (IPv6) unicast routing and configure interfaces
Note
to forward IPv6 traffic if the switch or switch stack is running the Network Essentials or Network Advantage
license.
Information About IP Routing
In some network environments, VLANs are associated with individual networks or subnetworks. In an IP
network, each subnetwork is mapped to an individual VLAN. Configuring VLANs helps control the size of
the broadcast domain and keeps local traffic local. However, network devices in different VLANs cannot
communicate with one another without a Layer 3 device (router) to route traffic between the VLAN, referred
to as inter-VLAN routing. You configure one or more routers to route traffic to the appropriate destination
VLAN.
This figure shows a basic routing topology. Switch A is in VLAN 10, and Switch B is in VLAN 20. The router
has an interface in each VLAN.
Figure 2: Routing Topology Example
When Host A in VLAN 10 needs to communicate with Host B in VLAN 10, it sends a packet addressed to
that host. Switch A forwards the packet directly to Host B, without sending it to the router.
Routing Configuration Guide, Cisco IOS XE Everest 16.6.x (Catalyst 9500 Switches)
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Configuration Examples for Multi-VRF CE, page 176
Configuring Unicast Reverse Path Forwarding, page 179
Protocol-Independent Features, page 179
Monitoring and Maintaining the IP Network, page 203
Feature Information for IP Unicast Routing, page 203
Configuring IP Unicast Routing