Key Concepts; Related Standards And Protocols - 3Com corebuilder 3500 Implementation Manual

Key Concepts

Related Standards
and Protocols
You can either configure network-based IP VLANs (IP VLANs with unique
Layer 3 IP addresses) or you can define a single VLAN with the protocol
type IP and then define multiple IP routing interfaces for that single
IP VLAN. See Chapter 11 for more information about defining
VLAN-based routing interfaces.
Per-port IEEE 802.1Q tagging — Selecting IEEE 802.1 tagging on a
per-port basis dictates that frames be encapsulated and tagged as
specified in the IEEE 802.1Q standard. See "Port-based
VLANs","Protocol-based VLANs", and "Network-based IP VLANs"
later in this chapter for specific information on tagging for the types
of VLANs.
Before you configure VLANs, review the following key concepts.
The following standards and protocols apply to the VLANs that you can
configure on your system:
IEEE 802.1Q — A proposed standard for VLANs, it is aimed at:
Defining an architecture to logically partition bridged LANs and
provide services to defined user groups, independent of physical
location.
Allowing interoperability among multivendor equipment.
IEEE 802.1Q defines the bridging rules for VLANs, that is, ingress and
egress rules, as defined in "Key Concepts" (and described in detail in
"Rules of VLAN Operation" later in this chapter).
The standard also specifies a tag format that embeds explicit VLAN
membership information in a 12-bit VLAN ID (VID) that provides 4094
possible VLANs. (Standard IEEE 802.1p uses this same frame format,
but also takes advantage of an additional 3 bits for specifying the
priority levels used for class of service differentiation.)
Generic Attribute Registration Protocol (GARP) — This protocol is
defined in IEEE 802.1p, which is a supplement to the IEEE 802.1D
standard. GARP is a Layer 2 transport mechanism that allows switches
and end systems to propagate information across the switching
domain.
GARP VLAN Registration Protocol (GVRP) — This protocol, which
is defined in IEEE 802.1Q, defines dynamic registration of VLANs that
use IEEE 802.1Q tagging (the VLAN ID).
Key Concepts 159