Extreme Networks ExtremeWare XOS 10.1, Manual

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176 ExtremeWare XOS 10.1 Concepts Guide
IP Unicast Routing
Router Interfaces
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 switch.
NOTE
Each IP address and mask assigned to a VLAN must represent a unique IP subnet. You cannot
configure the same IP address and subnet on different VLANs.
In Figure 31, a BlackDiamond switch is depicted with two VLANs defined; Finance and Personnel. All
ports on slots 1 and 3 are assigned to Finance; all ports on slots 2 and 4 are assigned to Personnel. Finance
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 31: Routing between VLANs
1 2 3 4 A B 5 6 7 8
EX_070
1
Finance Personnel
2 3 4
192.207.36.0 192.207.35.0
192.207.36.14
192.207.35.13
192.207.35.11
192.207.36.12
192.207.36.1 192.207.35.1