User`s guide
Table Of Contents
- User’s Guide
- Introduction and Hardware
- Basic Configuration
- Advanced
- VLAN
- Static MAC Forward Setup
- Filtering
- Spanning Tree Protocol
- 11.1 STP/RSTP Overview
- 11.1.1 STP Terminology
- 11.1.2 How STP Works
- 11.1.3 STP Port States
- 11.1.4 Multiple RSTP
- 11.2 Spanning Tree Protocol Main Screen
- 11.3 Configure Rapid Spanning Tree Protocol
- 11.4 Rapid Spanning Tree Protocol Status
- 11.5 Configure Multiple Rapid Spanning Tree Protocol
- 11.6 Multiple Rapid Spanning Tree Protocol Status
- Bandwidth Control
- Broadcast Storm Control
- Mirroring
- Link Aggregation
- Port Authentication
- Port Security
- Classifier
- Policy Rule
- Queuing Method
- VLAN Stacking
- Multicast
- 22.1 Multicast Overview
- 22.1.1 IP Multicast Addresses
- 22.1.2 IGMP Filtering
- 22.1.3 IGMP Snooping
- 22.2 Multicast Status
- 22.3 Multicast Setting
- 22.4 IGMP Filtering Profile
- 22.5 MVR Overview
- 22.5.1 Types of MVR Ports
- 22.5.2 MVR Modes
- 22.5.3 How MVR Works
- 22.6 General MVR Configuration
- 22.7 MVR Group Configuration
- 22.7.1 MVR Configuration Example
- IP Application
- Management
- Maintenance
- 28.1 The Maintenance Screen
- 28.2 Firmware Upgrade
- 28.3 Restore a Configuration File
- 28.4 Backup a Configuration File
- 28.5 Load Factory Default
- 28.6 Save Configuration
- 28.7 Reboot System
- 28.8 FTP Command Line
- 28.8.1 Filename Conventions
- 28.8.2 FTP Command Line Procedure
- 28.8.3 GUI-based FTP Clients
- 28.8.4 FTP Restrictions
- Access Control
- 29.1 Access Control Overview
- 29.2 The Access Control Main Screen
- 29.3 About SNMP
- 29.3.1 Supported MIBs
- 29.3.2 SNMP Traps
- 29.3.3 Configuring SNMP
- 29.4 SSH Overview
- 29.5 How SSH works
- 29.6 SSH Implementation on the Switch
- 29.6.1 Requirements for Using SSH
- 29.7 Introduction to HTTPS
- 29.8 HTTPS Example
- 29.8.1 Internet Explorer Warning Messages
- 29.8.2 Netscape Navigator Warning Messages
- 29.8.3 The Main Screen
- 29.9 Service Port Access Control
- 29.10 Remote Management
- Diagnostic
- Syslog
- Cluster Management
- MAC Table
- IP Table
- ARP Table
- Routing Table
- Configure Clone
- Maintenance
- CLI and Troubleshooting
- Introducing Commands
- 38.1 Overview
- 38.2 Accessing the CLI
- 38.2.1 The Console Port
- 38.3 The Login Screen
- 38.4 Command Syntax Conventions
- 38.5 Changing the Password
- 38.6 Privilege Levels
- 38.7 Command Modes
- 38.8 Getting Help
- 38.8.1 List of Available Commands
- 38.9 Using Command History
- 38.10 Saving Your Configuration
- 38.10.1 Configuration File
- 38.10.2 Logging Out
- 38.11 Command Summary
- 38.11.1 User Mode
- 38.11.2 Enable Mode
- 38.11.3 General Configuration Mode
- 38.11.4 interface port-channel Commands
- 38.11.5 interface route-domain Commands
- 38.11.6 config-vlan Commands
- 38.12 mvr Commands
- User and Enable Mode Commands
- 39.1 Overview
- 39.2 show Commands
- 39.2.1 show system-information
- 39.2.2 show ip
- 39.2.3 show logging
- 39.2.4 show interface
- 39.2.5 show mac address-table
- 39.3 ping
- 39.4 traceroute
- 39.5 Copy Port Attributes
- 39.6 Configuration File Maintenance
- 39.6.1 Using a Different Configuration File
- 39.6.2 Resetting to the Factory Default
- Configuration Mode Commands
- 40.1 Change the Out of Band Management IP Address
- 40.2 Enabling IGMP Snooping
- 40.3 Configure IGMP Filter
- 40.4 Enabling STP
- 40.5 no Command Examples
- 40.5.1 Disable Commands
- 40.5.2 Resetting Commands
- 40.5.3 Re-enable commands
- 40.5.4 Other Examples of no Commands
- 40.6 Static Route Commands
- 40.7 Enabling MAC Filtering
- 40.8 Enabling Trunking
- 40.9 Enabling Port Authentication
- 40.9.1 RADIUS Server Settings
- 40.9.2 Port Authentication Settings
- Interface Commands
- 41.1 Overview
- 41.2 Interface Command Examples
- 41.2.1 interface port-channel
- 41.2.2 bpdu-control
- 41.2.3 broadcast-limit
- 41.2.4 bandwidth-limit
- 41.2.5 mirror
- 41.2.6 gvrp
- 41.2.7 ingress-check
- 41.2.8 frame-type
- 41.2.9 weight
- 41.2.10 egress set
- 41.2.11 qos priority
- 41.2.12 name
- 41.2.13 speed-duplex
- 41.2.14 test
- 41.3 Interface no Command Examples
- 41.3.1 no bandwidth-limit
- IEEE 802.1Q Tagged VLAN Commands
- 42.1 Configuring Tagged VLAN
- 42.2 Global VLAN1Q Tagged VLAN Configuration Commands
- 42.2.1 GARP Status
- 42.2.2 GARP Timer
- 42.2.3 GVRP Timer
- 42.2.4 Enable GVRP
- 42.2.5 Disable GVRP
- 42.3 Port VLAN Commands
- 42.3.1 Set Port VID
- 42.3.2 Set Acceptable Frame Type
- 42.3.3 Enable or Disable Port GVRP
- 42.3.4 Modify Static VLAN
- 42.3.5 Delete VLAN ID
- 42.4 Enable VLAN
- 42.5 Disable VLAN
- 42.6 Show VLAN Setting
- Multicast VLAN Registration Commands
- Routing Domain Command Examples
- Troubleshooting
- Introducing Commands
- Appendices and Index

GS-2724 User’s Guide
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CHAPTER 26
Differentiated Services
This chapter shows you how to configure Differentiated Services (DiffServ) on the Switch.
26.1 DiffServ Overview
Quality of Service (QoS) is used to prioritize source-to-destination traffic flows. All packets in
the flow are given the same priority. You can use CoS (class of service) to give different
priorities to different packet types.
DiffServ is a class of service (CoS) model that marks packets so that they receive specific per-
hop treatment at DiffServ-compliant network devices along the route based on the application
types and traffic flow. Packets are marked with DiffServ Code Points (DSCPs) indicating the
level of service desired. This allows the intermediary DiffServ-compliant network devices to
handle the packets differently depending on the code points without the need to negotiate paths
or remember state information for every flow. In addition, applications do not have to request
a particular service or give advanced notice of where the traffic is going.
26.1.1 DSCP and Per-Hop Behavior
DiffServ defines a new DS (Differentiated Services) field to replace the Type of Service (ToS)
field in the IP header. The DS field contains a 2-bit unused field and a 6-bit DSCP field which
can define up to 64 service levels. The following figure illustrates the DS field.
DSCP is backward compatible with the three precedence bits in the ToS octet so that non-
DiffServ compliant, ToS-enabled network device will not conflict with the DSCP mapping.
Figure 79 DiffServ: Differentiated Service Field
The DSCP value determines the forwarding behavior, the PHB (Per-Hop Behavior), that each
packet gets across the DiffServ network. Based on the marking rule different kinds of traffic
can be marked for different priorities of forwarding. Resources can then be allocated
according to the DSCP values and the configured policies.
26.1.2 DiffServ Network Example
The following figure depicts a simple DiffServ network consisting of a group of contiguous
DiffServ-compliant network devices.
DSCP (6 bits) DS (2 bits)