Enterasys Networks 8000/8600 - Manual (Page 18)

Features
6 Enterasys X-Pedition 8000/8600 Getting Started Guide
Port and Protocol VLANs
The X-Pedition supports the following types of Virtual LANs (VLANs):
• Port-based VLANs – A port-based VLAN is a set of ports that comprises a Layer-2 broadcast
domain. The X-Pedition confines MAC-layer broadcasts to the ports in the VLAN on which the
broadcast originates. X-Pedition ports outside the VLAN do not receive the broadcast.
• Protocol-based VLANs – A protocol-based VLAN is a named set of ports that comprises an IP
or IPX broadcast domain. The X-Pedition confines IP or IPX broadcasts to the ports within the
IP or IPX based VLAN. Protocol-based VLANs sometimes are called subnet VLANs or Layer-
3 VLANs.
You can include the same port in more than one VLAN, even in both port-based and protocol-based
VLANs. Moreover, you can define VLANs that span across multiple X-Peditions. To simplify
VLAN administration, the X-Pedition supports 802.1Q trunk ports, which allow you to use a single
port to “trunk” traffic from multiple VLANs to another X-Pedition or switch which supports
802.1Q.
Routing
The X-Pedition provides wire-speed routing for the following protocols:
• Internet Protocol (IP) – protocol that switching and routing devices use for moving traffic
within the Internet and within many corporate intranets
• Internet Packet Exchange (IPX) – protocol by Novell used in NetWare products
• Appletalk – protocol used to allow users of dissimilar computer systems to share information
over a network without regard for special formats and internal differences.
Note: All other protocols that require routing must be tunneled using IP.
By default, the X-Pedition uses one MAC address for all interfaces. The X-Pedition can be
configured to have a separate MAC address for each IP interface and a separate MAC address for
each IPX interface. When the X-Pedition receives a packet whose destination MAC address is one
of the X-Pedition’s IP or IPX interface MAC addresses, the line card that received the packet from
the network uses information in the line card’s Layer-3 lookup tables (or information supplied by
the control module) to route the packet to its IP destination(s). (See Control Modules
on page 14 for
information about the control module.)
You can create only one IP and IPX interface on a single port or VLAN. You can add secondary IP
addresses to the same IP interface. When you add an interface to a set of ports, you are adding a
VLAN to those ports. Ports that contain IP and IPX interfaces can also still perform Layer-2
bridging.
In addition to hardware based, wire-speed routing, the Advanced Routing Engine (ARE) feature
extends X-Pedition’s capabilities to support software based routing. This capability is perfect for
less demanding protocols like AppleTalk.