LevelOne GTL-2691 - Manual (Page 78)

C HAPTER 1 | Introduction
Description of Software Features
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A DDRESS R ESOLUTION
P ROTOCOL
The switch uses ARP and Proxy ARP to convert between IP addresses and
MAC (hardware) addresses. This switch supports conventional ARP, which
locates the MAC address corresponding to a given IP address. This allows
the switch to use IP addresses for routing decisions and the corresponding
MAC addresses to forward packets from one hop to the next. Either static
or dynamic entries can be configured in the ARP cache.
Proxy ARP allows hosts that do not support routing to determine the MAC
address of a device on another network or subnet. When a host sends an
ARP request for a remote network, the switch checks to see if it has the
best route. If it does, it sends its own MAC address to the host. The host
then sends traffic for the remote destination via the switch, which uses its
own routing table to reach the destination on the other network.
M ULTICAST F ILTERING
Specific multicast traffic can be assigned to its own VLAN to ensure that it
does not interfere with normal network traffic and to guarantee real-time
delivery by setting the required priority level for the designated VLAN. The
switch uses IGMP Snooping and Query for IPv4 and MLD Snooping and
Query for IPv6, and IGMP at Layer 3 to manage multicast group
registration. It also supports Multicast VLAN Registration (MVR for IPv4 and
MVR6 for IPv6) which allows common multicast traffic, such as television
channels, to be transmitted across a single network-wide multicast VLAN
shared by hosts residing in other standard or private VLAN groups, while
preserving security and data isolation for normal traffic.
L INK L AYER
D ISCOVERY P ROTOCOL
LLDP is used to discover basic information about neighboring devices
within the local broadcast domain. LLDP is a Layer 2 protocol that
advertises information about the sending device and collects information
gathered from neighboring network nodes it discovers.
M ULTICAST R OUTING
Routing for multicast packets is supported by the Protocol-Independent
Multicasting - Dense Mode and Sparse Mode (PIM-DM, PIM-SM) protocols.
These protocols work in conjunction with IGMP to filter and route multicast
traffic. PIM is a very simple protocol that uses the routing table of the
unicast routing protocol enabled on an interface. Dense Mode is designed
for areas where the probability of multicast clients is relatively high, and
the overhead of frequent flooding is justified. While Sparse mode is
designed for network areas, such as the Wide Area Network, where the
probability of multicast clients is low. PIM-DM and PIM-SM are supported
for IPv4 and PIM-SM for IPv6.