Primary VLAN. This document shows how to view and change the primary VLAN for the HP Procurve Series 2500 Switches:

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1 Primary VLAN This document shows how to view and change the primary VLAN for the HP Procurve Series 2500 Switches: J4812A HP Procurve Switch 2512 J4813A HP Procurve Switch 2524 Definitions: Default VLAN. In factory default configuration, the switch has one VLAN, called the DEFAULT_VLAN. Primary VLAN. The primary VLAN performs five functions: 1) it has the switch's primary network management IP address; 2) the stack management feature; 3) learning the default gateway from DHCP and Bootp; and 4) learning the TIMEP server Copyright Hewlett-Packard Company, Page 1

2 from DHCP and Bootp; and 5) learning the IP TTL (Time To Live) from DHCP and Bootp; operate on the primary VLAN. This is done to prevent the switch from receiving conflicting information (that is: different default gateway addresses or TTL values) on multiple VLANs. VID. VLAN ID. TTL. Time To Live. This IP datagram parameter specifies how long in seconds an outgoing packet should exist in the network. Default VLAN Notes: 1. In factory default configuration, the default VLAN: has the name "DEFAULT_VLAN". has VID = 1. includes all of the switch's ports. has all of its ports untagged. 2. You can change the name of the default VLAN, but you cannot delete it or change it's VID. 3. The switch requires that all ports be members of a VLAN. So, in order to remove a port from the default VLAN, you must first assign that port to another VLAN. In this way, you can move all ports out of the default VLAN, if you wish. 4. VLAN support is always on. By contrast, the Procurve switch models 1600M, 2400M, 2424M, 4000M and 8000M have VLAN support deactivated, by default. Primary VLAN Notes: 1. In factory default configuration, the primary VLAN is the default VLAN. 2. The user can configure any VLAN to be the primary VLAN. 3. The switch sends and receives its stacking management packets only on the primary VLAN (for more details on stack management, see the Management and Configuration Guide's section "HP Procurve Stack Management".). Copyright Hewlett-Packard Company, Page 2

3 4. The switch learns its VLANs' IP addresses and subnet masks from DHCP or Bootp packets received on any VLAN. The switch can only learn its default gateway address, Timep server address, and IP TTL value from DHCP or Bootp packets it receives on its primary VLAN. The switch ignores default gateway addresses, Timep server addresses and TTL values learned from DHCP and Bootp packets it receives on other VLANs. Of course, the user may configure the default gateway address and Timep server address using the CLI, menu or web interfaces (see details below). 5. The switch uses one default gateway. In spite of having one default gateway, the switch can communicate (ping, network management, TELNET, etc.) with remote (that is: through a router) subnets from any of its VLANs. The switch has no need for more than one default gateway. Procurve switch models 1600M, 2400M, 2424M, 4000M and 8000M have a different default gateway support model. The CLI, menu and web instructions below apply to software version F Viewing the Primary VLAN Using the Menu Interface: See the Management and Configuration Guide's chapter "Configuring Advanced Features", section "Menu: Configuring VLAN Parameters. In the menu, go to: Switch Configuration -> VLAN Menu -> VLAN Support. This screen displays the current primary VLAN. Changing the Primary VLAN Using the Menu Interface: Choose Switch Configuration, then VLAN Menu, then VLAN Support. By choosing Edit, t you can select a different VLAN as primary. Viewing the Primary VLAN Using the CLI: Display the primary VLAN using the show vlan command. You can execute this command in any mode. Copyright Hewlett-Packard Company, Page 3

4 Changing the Primary VLAN Using the CLI: Change the primary VLAN using the global configuration mode command, primaryvlan <vlan-id>, where you specify the new primary VLAN by VID, not by VLAN name. For example, to make VLAN 22 the primary VLAN: HP2512(config)# primary-vlan 22 Viewing the Primary VLAN Using the Web Interface: To view the primary VLAN setting, click on the Configuration tab, then click on VLAN Configuration. Changing the Primary VLAN Using the Web Interface: To change the Primary VLAN Using the Web Interface, click on the Configuration tab, then click on VLAN Configuration, then click on ADD/REMOVE VLANs, select your new primary VLAN from the list in the box labeled Current VLAN Definitions, then click on Set Primary VLAN. Verification Commands: See the instructions above for viewing the primary VLAN. Troubleshooting Scenarios: Symptom: The switch does not learn the Timep server address, the default gateway address or TTL from DHCP or Bootp. Possible Issue: The switch can learn its Timep server address, default gateway address or TTL from DHCP or Bootp packets received on the primary VLAN, but not from DHCP or Bootp packets received on other VLANs. Solution: If you want the switch to learn its Timep server address, default gateway address or TTL from DHCP or Bootp, make sure there is a DHCP or Bootp server on the switch's primary VLAN. The user can set the current date and time using the CLI configuration mode command, time. The user can set the Timep server address, default gateway address or TTL by: 1) using the CLI configuration mode ip command; or Copyright Hewlett-Packard Company, Page 4

5 2) using the menu's Switch Configuration -> IP Configuration screen; or 3) using the web interface's Configuration -> IP Configuration screen. Note: this applies to the default gateway address only. Users cannot set the Timep server address or TTL using the web interface. Symptom: The stack commander cannot locate any candidates. Possible Issue: The Commander and Candidates are not connected by their respective switches' primary VLANs. See the Management and Configuration Guide's chapter "Troubleshooting", section "Unusual Network Activity", subsection "Stacking-related Problems". Note that the stack management protocol is not routable. Solution: Make sure that the stack commander's primary VLAN has connectivity to the primary VLANs of the candidates. This connection must not pass through a router. Symptom: The user replaced a Procurve switch model 1600M, 2400M, 2424M, 4000M or 8000M with a Procurve 2500 series switch, and has problems forwarding 802.1Q tagged packets. Possible Issue: (Note: This is not a primary VLAN-specific issue.) With respect to forwarding, there is an important difference in default behavior between the 2500 series switches and the other models listed above. In factory default mode the 2500 series switches have VLAN support on, while the other switch models listed above have VLAN support off. The other switch models will receive and process all incoming packets, whether tagged or not. In factory default configuration, the 2500 series switches will not process tagged packets, because the default VLAN's ports are set to Untagged. For this reason, the 2500 series switches will discard incoming tagged packets. It is difficult to troubleshoot this problem using the switch counters, because the switch 2500's transmit and receive counters will increment as if traffic is successfully being transmitted and received, even though the packets will not be processed. These packets will not cause any switch error counters to increment. Solution: : The Installation and Getting Started Guide has excellent advice for verifying communication. See the chapter "Troubleshooting", section "Hardware Diagnostic Tests", subsection "Testing Switch-to-Device Network Communications". For a discussion of the issues involved in device-to-device VLAN configuration, see the related discussion in the Management and Configuration Guide's chapter "Configuring Advanced Features", section "Port-Based Virtual LANs", subsection "VLAN Tagging Information". At the end of this section is a table introduced with "To summarize:" This table gives an excellent summary of how to correctly configure directly-connect devices. Copyright Hewlett-Packard Company, Page 5