Forwarding TAGGED/UNTAGGED Frames | Enterasys Networks 5G1XX, 5H1XX

Forwarding Tagged/Untagged Frames

2.3FORWARDING TAGGED/UNTAGGED FRAMES

Ports can be assigned to multiple tagged or untagged VLANs. Each port on the switch is therefore capable of passing tagged or untagged frames. To forward a frame from a VLAN-aware device to a VLAN-unaware device, the switch first decides where to forward the frame, and then strips off the VLAN tag. However, to forward a frame from a VLAN-unaware device to a VLAN-aware device, the switch first decides where to forward the frame, and then inserts a VLAN tag reflecting this port’s default VID. The default PVID is VLAN 1, but this can be changed as described in Section 7.15.

Figure B-1 Example of Multi-Switch VLAN Configuration

VLAN-aware switch		VLAN-aware switch

VLAN 1.2 (802.1Q tags)

VLAN 1 (802.1Q tags)

VLAN-aware switch

Trunk VLAN 1.2 (802.1Q tags)

VLAN-aware switch

VLAN 1.2 (802.1Q tags)

VLAN 3 (untagged)

VLAN-aware switch

VLAN 3 (untagged)

VLAN-aware switch

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B.4 FORWARDING TRAFFIC WITH UNKNOWN VLAN TAGS

Up to 4096 VLANs are supported by the IEEE 802.1Q standard, but this switch only supports 1024 VLANs. Therefore, if this switch is attached to any device that forwards frames with unknown VLAN tags, or to end stations which issue VLAN registration requests for unknown VLANs, this traffic will be dropped.

Virtual LANs (VLANs) B-3

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Enterasys Networks 5G1XX, 5H1XX manual Forwarding TAGGED/UNTAGGED Frames, Forwarding Traffic with Unknown Vlan Tags

Contents

9033583-01 Page Page Enterasys NETWORKS, INC Program License Agreement Page Page Contents System Information Menu Screens System Restart Menu Screen Spanning Tree Concepts Figures 802.1Q Tables Page Using this Guide About This GuideStructure of this Guide Structure of This Guide Document Conventions Related Documents Backspace Typographical and Keystroke ConventionsEnter ESC FTP Getting HelpPage Overview Introduction In-Band vs. Out-of-Band Management Agent Local Management Requirements Navigating Local Management ScreensPage Management Terminal Setup Local Management RequirementsConsole Cable Connection Management Terminal Connection Management Terminal Setup Parameters Xoff VT100ID Telnet Connections Accessing Local Management Local Management Screen Hierarchy Menu name Selectable Items Accessing Local Management Screens How to Use the Screen Menus Password Screen Factory Defaults SVL Screen Navigation Path Main Menu Screens System Information Menu For details, refer to Chapter Main Menu Management Setup Menu For details, refer to Chapter Exit For details, refer to Chapter System Information Menu Screen System Information Menu Screens Displaying System Information Default System Name Parameter Description Switch Information Screen Displaying Switch Version and Module Information Management Setup Menu Screens Network Configuration Menu Management Setup Menu Screen Network Configuration Menu Screen Changing the Network Configuration IP Configuration Screen IP Configuration USER-CONFIG IP Connectivity Test Screen IP Connectivity Test Ping Http Configuration Screen Http Configuration Console Mode Configuring the Serial Port Console ModeNone Assigning Snmp Parameters Snmp Configuration Menu Screen To Section Snmp Communities Screen Configuring Community Names Disabled Configuring IP Trap Managers 10 Console Login Configuration Screen Console Login Configuration Admin Setting the Startup Configuration Downloading System Software 12 Tftp Download Screen Download Method Device Control Menu Screens Configuring the Switch Device Control Menu Screen To .11 and Section Port Configuration Screen Configuring Port Parameters Enabled DI SabledAuto Port Information Screen Viewing the Current Port Configuration Parameter Description Spanning Tree ConfigurationSelection Menu Screen Using the Spanning Tree Algorithm Enabled Configuring STA Bridge 10Device Control Menu Screens STA Tree Port Configuration Screen Configuring STA for Ports Enables or disables the port to forward packets. All Spanning Tree Information Selection Menu Screen Viewing the Current Spanning Tree Configuration STA Bridge Information Screen Displaying the Current STA Bridge Parameter Description STA Port Information Screen Displaying the Current STA for Ports or Modules Parameter Description 10 Mirror Port Configuration Screen Using a Mirror Port for Analysis Configuring Smarttrunks 11 SmartTrunking Configuration Screen Igmp Multicast Filtering SaveShow 12 Igmp Configuration Screen Configuring Igmp 13 Extended Bridge Configuration Screen Configuring Bridge MIB Extensions All VLANs Port Priority Configuration Configuring Traffic Classes 10.2 802.1P Port Traffic Class Information 15 802.1P Port Priority Configuration Screen 16 802.1P Port Traffic Class Information Screen Configuring Virtual LANs MAX Vlan ID 12 802.1Q Vlan Base Information VID 13 802.1Q Vlan Current Table Information 14 802.1Q Vlan Static Table Configuration Range 20 802.1Q Vlan Port Configuration Screen 15 802.1Q Vlan Port Configuration Vlan Pvid 21 Static Unicast Address Table Configuration Screen Configuring Static Unicast Addresses Unlock Port-Disables the port locking mode. For details Page Network Monitoring Menu Screens Monitoring the Switch Port Statistics Port Displaying Port Statistics Parameter Description Rmon Statistics Screen Displaying Rmon Statistics Parameter Description Displaying the Unicast Address Table Unicast Address Table Screen MAC IP Multicast Registration Table Screen Displaying the IP Multicast Registration Table Vlan ID assigned to this multicast group Page System Restart Menu Screen Resetting the System Post Logging OFF the System Common Tasks Configuring and Monitoring the Switch Setting Password Protection Assigning AN IP Address Checking Network Configuration StatusConnecting VIA Telnet Setting Snmp Management Access Configuring Port Mirroring Viewing Switch Statistics Downloading via the Serial Port Downloading a Software Upgrade Downloading via Tftp Configuring VLANs Configuring Spanning Tree Parameters Select 802.1Q Vlan Static Table Configuration Menu Configuring Class of Service Configuring Port Operation Configuring the Unicast Address Table 10.15.1Port Locking 10.15.2Unlocking the PortVlan ID Select SmartTrunking Configuration Setting a Default Gateway Configuring SmartTrunkS Page Snmp Protocol Snmp Management MIB Objects RFC 1213 MIBMIB RFC 1757 Rmon MIB RFC 1493 Bridge MIBRFC 1573 Interfaces Evolution MIB RFC 1643 ETHERNET-LIKE MIB Ieee 802.1Q Q MIB Enterasys Proprietary MIB ExtensionsCompiling MIB Extensions Enterasys Website General Spanning Tree Concepts Spanning Tree Protocol in a Network Spanning Tree Protocol Parameters Spanning Tree Protocol Operation Handling Duplicate Paths Page VLANs and Frame Tagging Virtual LANs VLANs Vlan Configuration Forwarding Traffic with Unknown Vlan Tags Forwarding TAGGED/UNTAGGED FramesPage Class of Service Figure C-1 Class of Service Example IP Multicast Filtering Page Numerics Index Index-2 Index-3