Quick Reference Guide

PowerConnect B-Series TI24X Configuration Guide 569
53-1002269-02
Overview
21
To increase the size of the IP forwarding cache, refer to the section “Displaying and modifying
system parameter default settings” on page 184.
Layer 4 session table
The Layer 4 session provides a fast path for forwarding packets. A session is an entry that contains
complete Layer 3 and Layer 4 information for a flow of traffic. Layer 3 information includes the
source and destination IP addresses. Layer 4 information includes the source and destination TCP
and UDP ports. For comparison, the IP forwarding cache contains the Layer 3 destination address
but does not contain the other source and destination address information of a Layer 4 session
table entry.
The Layer 2 Switch or Layer 3 Switch selects the session table instead of the IP forwarding table for
fast-path forwarding for the following features:
• Layer 4 Quality-of-Service (QoS) policies
• IP access policies
To increase the size of the session table, refer to the section “Displaying and modifying system
parameter default settings” on page 184. The ip-qos-session parameter controls the size of the
session table.
IP route exchange protocols
Layer 3 Switches support the following IP route exchange protocols:
• Routing Information Protocol (RIP)
• Open Shortest Path First (OSPF)
All these protocols provide routes to the IP route table. You can use one or more of these protocols,
in any combination. The protocols are disabled by default. For configuration information, refer to
the following:
• Chapter 22, “Configuring RIP”
• Chapter 23, “Configuring OSPF Version 2 (IPv4)”
IP multicast protocols
Layer 3 Switches also support the following Internet Group Membership Protocol (IGMP) based IP
multicast protocols:
• Protocol Independent Multicast – Dense mode (PIM-DM)
• Protocol Independent Multicast – Sparse mode (PIM-SM)
For configuration information, refer to Chapter 19, “Configuring IP Multicast Protocols”.
NOTE
Layer 2 Switches support IGMP and can forward IP multicast packets. Refer to Chapter 18,
“Configuring IP Multicast Traffic Reduction for PowerConnect B-Series TI24X Switches”.