Extreme 3804 User Guide

Page of 227
9-2
S
UMMIT
 S
WITCH
 I
NSTALLATION
 
AND
 U
SER
 G
UIDE
IP U
NICAST
 R
OUTING
R
OUTER
 I
NTERFACES
The routing software and hardware routes IP traffic between router interfaces. A router 
interface is simply a 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 Summit.
Each IP address and mask assigned to a VLAN must represent a unique IP 
subnet. You cannot configure the same IP subnet on different VLANs.
, A Summit is depicted with two VLANs defined; Finance and Personnel
Ports 1 and 3 are assigned to Finance; ports 2 and 4 are assigned to PersonnelFinance 
belongs to the IP network 192.207.35.0; the router interface for Finance is assigned the IP 
address 192.206.35.1. Personnel belongs to the IP network 192.207.36.0; its router 
interface is assigned IP address 192.207.36.1. Traffic within each VLAN is switched 
using the Ethernet MAC addresses. Traffic between the two VLANs is routed using the 
IP addresses.
Figure 9-1: Routing between VLANs
1
Finance
Personnel
192.207.35.11
192.207.36.12
192.207.35.13
192.207.36.14
192.207.36.1
192.207.35.1
2
3
4
192.207.36.0
192.207.35.0
Summit.bk : 9ROUT.FM  Page 2  Thursday, June 18, 1998  9:27 AM