Specifications

Configuring Routing Between VLANs
Information About Routing Between VLANs
10
IEEE 802.10 Protocol
The IEEE 802.10 protocol provides connectivity between VLANs. Originally developed to address the
growing need for security within shared LAN/MAN environments, it incorporates authentication and
encryption techniques to ensure data confidentiality and integrity throughout the network. Additionally,
by functioning at Layer 2, it is well suited to high-throughput, low-latency switching environments. The
IEEE 802.10 protocol can run over any LAN or HDLC serial interface.
Procedures for configuring routing between VLANs with IEEE 802.10 encapsulation are provided in the
“Configuring Routing Between VLANs with IEEE 802.10 Encapsulation” section on page 31.
IEEE 802.1Q Protocol
The IEEE 802.1Q protocol is used to interconnect multiple switches and routers, and for defining VLAN
topologies. Cisco currently supports IEEE 802.1Q for Fast Ethernet and Gigabit Ethernet interfaces.
Note Cisco does not support IEEE 802.1Q encapsulation for Ethernet interfaces.
Procedures for configuring routing between VLANs with IEEE 802.1Q encapsulation are provided in
the “Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation” section on page 34.
ATM LANE Protocol
The ATM LAN Emulation (LANE) protocol provides a way for legacy LAN users to take advantage of
ATM benefits without requiring modifications to end-station hardware or software. LANE emulates a
broadcast environment like IEEE 802.3 Ethernet on top of an ATM network that is a point-to-point
environment.
LANE makes ATM function like a LAN. LANE allows standard LAN drivers like NDIS and ODI to be
used. The virtual LAN is transparent to applications. Applications can use normal LAN functions
without the underlying complexities of the ATM implementation. For example, a station can send
broadcasts and multicasts, even though ATM is defined as a point-to-point technology and does not
support any-to-any services.
To accomplish this, special low-level software is implemented on an ATM client workstation, called the
LAN Emulation Client (LEC). The client software communicates with a central control point called a
LAN Emulation Server (LES). A broadcast and unknown server (BUS) acts as a central point to
distribute broadcasts and multicasts. The LAN Emulation Configuration Server (LECS) holds a database
of LECs and the ELANs they belong to. The database is maintained by a network administrator.
These protocols are described in detail in the Cisco Internetworking Design Guide.
ATM LANE Fast Simple Server Replication Protocol
To improve the ATM LANE Simple Server Replication Protocol (SSRP), Cisco introduced the ATM
LANE Fast Simple Server Replication Protocol (FSSRP). FSSRP differs from LANE SSRP in that all
configured LANE servers of an ELAN are always active. FSSRP-enabled LANE clients have virtual
circuits (VCs) established to a maximum of four LANE servers and BUSs at one time. If a single LANE
server goes down, the LANE client quickly switches over to the next LANE server and BUS, resulting
in no data or LE ARP table entry loss and no extraneous signalling.