LevelOne GTL-2881, User Manual

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Chapter 1
| Introduction
Description of Software Features
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allows you select traffic based on Layer 2, Layer 3, or Layer 4 information contained
in each packet. Based on network policies, different kinds of traffic can be marked
for different kinds of forwarding.
Ethernet Ring
Protection Switching
ERPS can be used to increase the availability and robustness of Ethernet rings, such
as those used in Metropolitan Area Networks (MAN). ERPS provides Layer 2 loop
avoidance and fast reconvergence in Layer 2 ring topologies, supporting up to 255
nodes in the ring structure. It can also function with IEEE 802.1ag to support link
monitoring when non-participating devices exist within the Ethernet ring.
IP Routing
The switch provides Layer 3 IP routing. To maintain a high rate of throughput, the
switch forwards all traffic passing within the same segment, and routes only traffic
that passes between different subnetworks. The wire-speed routing provided by
this switch lets you easily link network segments or VLANs together without having
to deal with the bottlenecks or configuration hassles normally associated with
conventional routers.
Routing for unicast traffic is supported with static routing, and Routing Information
Protocol (RIP).
Static Routing – Traffic is automatically routed between any IP interfaces
configured on the switch. Routing to statically configured hosts or subnet
addresses is provided based on next-hop entries specified in the static routing
table.
RIP – This protocol uses a distance-vector approach to routing. Routes are
determined on the basis of minimizing the distance vector, or hop count, which
serves as a rough estimate of transmission cost.
OSPF – This approach uses a link state routing protocol to generate a shortest-path
tree, then builds up its routing table based on this tree. OSPF produces a more
stable network because the participating routers act on network changes
predictably and simultaneously, converging on the best route more quickly than
RIP.BGP – This protocol uses a path vector approach to connect autonomous
systems (AS) on the Internet. BGP maintains a table of IP network prefixes which
designate network reachability among autonomous systems based the path of ASs
to the destination, and next hop information. It makes routing decisions based on
path, network policies and/or rule sets. For this reason, it is more appropriately
termed a reachability protocol rather than a routing protocol.
Policy-based Routing for BGP – The next-hop behavior for ingress IP traffic can be
determined based on matching criteria.