User`s guide
Table Of Contents
- Title
- Notice
- Contents
- Figures
- Tables
- About This Guide
- Introduction
- Local Management Requirements
- Accessing Local Management
- 3.1 Navigating Local Management Screens
- 3.2 Password Screen
- 3.3 Main Menu Screen
- 3.4 Module Selection Screen
- 3.5 Module Menu Screen
- 3.6 Overview of Security Methods
- 3.7 Security Menu Screen
- 3.8 Passwords Screen
- 3.9 Radius Configuration Screen
- 3.10 Name Services Configuration Screen
- 3.11 System Authentication Configuration Screen
- 3.12 EAP (Port) Configuration Screen
- 3.13 EAP Statistics Menu Screen
- 3.14 MAC Port Configuration Screen
- 3.15 MAC Supplicant Configuration Screen
- Chassis Menu Screens
- 4.1 Chassis Menu Screen
- 4.2 Chassis Configuration Screen
- 4.3 SNMP Configuration Menu Screen
- 4.4 SNMP Community Names Configuration Screen
- 4.5 SNMP Traps Configuration Screen
- 4.6 Chassis Environmental Information Screen
- 4.7 Redirect Configuration Menu Screen (Chassis)
- 4.8 Port Redirect Configuration Screen
- 4.9 VLAN Redirect Configuration Screen
- Module Configuration Menu Screens
- 5.1 Module Configuration Menu Screen
- 5.2 General Configuration Screen
- 5.2.1 Setting the IP Address
- 5.2.2 Setting the Subnet Mask
- 5.2.3 Setting the Default Gateway
- 5.2.4 Setting the TFTP Gateway IP Address
- 5.2.5 Setting the Module Name
- 5.2.6 Setting the Module Date
- 5.2.7 Setting the Module Time
- 5.2.8 Entering a New Screen Refresh Time
- 5.2.9 Setting the Screen Lockout Time
- 5.2.10 Configuring the COM Port
- 5.2.11 Clearing NVRAM
- 5.2.12 Enabling/Disabling IP Fragmentation
- 5.3 SNMP Configuration Menu Screen
- 5.4 SNMP Community Names Configuration Screen
- 5.5 SNMP Traps Configuration Screen
- 5.6 Access Control List Screen
- 5.7 System Resources Information Screen
- 5.8 FLASH Download Configuration Screen
- Port Configuration Menu Screens
- 6.1 Port Configuration Menu Screen
- 6.2 Ethernet Interface Configuration Screen
- 6.3 Ethernet Port Configuration Screen
- 6.4 HSIM/VHSIM Configuration Screen
- 6.5 Redirect Configuration Menu Screen
- 6.6 Port Redirect Configuration Screen
- 6.7 VLAN Redirect Configuration Screen
- 6.8 Link Aggregation Screen (802.3ad Main Menu Screen)
- 6.9 Broadcast Suppression Configuration Screen
- 802.1 Configuration Menu Screens
- 802.1Q VLAN Configuration Menu Screens
- 8.1 Summary of VLAN Local Management
- 8.2 802.1Q VLAN Configuration Menu Screen
- 8.3 Static VLAN Configuration Screen
- 8.4 Static VLAN Egress Configuration Screen
- 8.5 Current VLAN Configuration Screen
- 8.6 Current VLAN Egress Configuration Screen
- 8.7 VLAN Port Configuration Screen
- 8.8 VLAN Classification Configuration Screen
- 8.9 Protocol Port Configuration Screen
- 802.1p Configuration Menu Screens
- 9.1 802.1p Configuration Menu Screen
- 9.2 Port Priority Configuration Screen
- 9.3 Traffic Class Information Screen
- 9.4 Traffic Class Configuration Screen
- 9.5 Transmit Queues Configuration Screen
- 9.6 Priority Classification Configuration Screen
- 9.7 Protocol Port Configuration Screen
- 9.8 Rate Limiting Configuration Screen
- Layer 3 Extensions Menu Screens
- Module Statistics Menu Screens
- Network Tools Screens
- VLAN Operation and Network Applications
- 13.1 Defining VLANs
- 13.2 Types of VLANs
- 13.3 Benefits and Restrictions
- 13.4 VLAN Terms
- 13.5 VLAN Operation
- 13.6 Configuration Process
- 13.7 VLAN Switch Operation
- 13.8 VLAN Configuration
- 13.9 Summary of VLAN Local Management
- 13.10 Quick VLAN Walkthrough
- 13.11 Examples
- 13.12 Example 1, Single Switch Operation
- 13.13 Example 2, VLANs Across Multiple Switches
- 13.14 Example 3, Filtering Traffic According to a Layer 4 Classification Rule
- 13.15 Example 4, Securing Sensitive Information According to Subnet
- 13.16 Example 5, Using Dynamic Egress to Control Traffic
- 13.17 Example 6, Locking a MAC Address to a Port Using Classification Rules
- Generic Attribute Registration Protocol (GARP)
- About IGMP
- Index

Example 3, Filtering Traffic According to a Layer 4 Classification Rule
13-32 VLAN Operation and Network Applications
13.14 EXAMPLE 3, FILTERING TRAFFIC ACCORDING TO A LAYER 4
CLASSIFICATION RULE
This example illustrates how to filter out broadcast transmissions at Layer 4 from other parts of a
network.
In this example, illustrated in Figure 13-16, switches S1 and S2 have already been configured and
operating. However, it was discovered that the Routing Information Protocol (RIP) broadcast
frames from routers R1 and R2 were flooding the subnetwork of Switches S1 and S2.
Figure 13-16 Example 5, Filtering Traffic According to a Classification
13.14.1 Solving the Problem
To prevent the RIP broadcasts from flooding the users’ terminals connected to S1 and S2, a new
VLAN will be added to each switch, but not assigned to any ports (creating a Null VLAN). Then
each switch will be configured with a Layer 4 classification rule that will classify each RIP
broadcast frame received on Port 25 of each switch to the Null VLAN. Since the Null VLAN is not
associated with any ports, the frame will be dropped and not transmitted out any port.
In this example, the switches have already been configured and operating. The following covers
only those steps needed to configure each switch to eliminate the problem.
Switches 1 and 2
Each switch is set as follows:
1. A VLAN is added to the list of VLANs in the Module/VLAN Configuration screen and assigned
to an FDB ID. In this example, the switch is set as follows:
• VLAN ID 99, FDB ID 99, with a VLAN Name of Null VLAN
2599_27
Users Users
R2
R1
Port 25 Port 25
S1
S2