Table of Contents

Chapter 1 GVRP Configuration. 1-1

1.1 Introduction to GVRP. 1-1

1.1.1 GVRP Mechanism.. 1-1

1.1.2 GVRP Packet Format 1-3

1.1.3 Protocol Specifications. 1-4

1.2 GVRP Configuration. 1-4

1.2.1 Configuration Prerequisite. 1-4

1.2.2 Configuration Procedure. 1-4

1.3 Displaying and Debugging GVRP. 1-6

1.4 GVRP Configuration Example. 1-6

1.4.1 Network requirements. 1-6

1.4.2 Network diagram.. 1-6

1.4.3 Configuration procedure. 1-7

 

Chapter 1  GVRP Configuration

1.1  Introduction to GVRP

GARP VLAN registration protocol (GVRP) is an implementation of generic attribute registration protocol (GARP). It maintains dynamic VLAN registration information and propagates the information to other switches by adopting the same mechanism as that of GARP.

 

 

After the GVRP feature is enabled on a switch, the switch receives the VLAN registration information from other switches to dynamically update the local VLAN registration information (including VLAN members, ports through which the VLAN members can be reached, and so on). The switch also propagates the local VLAN registration information to other switches so that all the switching devices in the same switched network can have the same VLAN information. The VLAN registration information includes not only the static registration information configured locally, but also the dynamic registration information received from other switches.

1.1.1  GVRP Mechanism

I. GARP timers

The information exchange between GARP members is completed by messages. The messages performing important functions for GARP fall into three types: Join, Leave and LeaveAll.

l           When a GARP entity expects other switches to register certain attribute information of its own, it sends out a Join message.

l           When a GARP entity expects other switches to unregister certain attribute information of its own, it sends out a Leave message.

l           Once a GARP entity starts up, it starts the LeaveAll timer. After the timer times out, the GARP entity sends out a LeaveAll message.

The Join message and the Leave message are used together to complete the unregistration and re-registration of information. Through message exchange, all the attribute information to be registered can be propagated to all the switches in the same switched network.

GARP uses the following timers:

l           Hold: When a GARP entity receives a piece of registration information, it does not send out a Join message immediately. Instead, to save the bandwidth resources, it starts the Hold timer and puts all received registration information before the timer times out into one Join message and sends out the message after the timer times out.

l           Join: To transmit the Join messages reliably to other entities, a GARP entity sends each Join message two times. The Join timer is used to define the interval at which each Join message is sent.

l           Leave: When a GARP entity expects to unregister a piece of attribute information, it sends out a Leave message. Any GARP entity receiving this message starts its Leave timer, and unregisters the attribute information if it does not receives a Join message again before the timer times out.

l           LeaveAll: Once a GARP entity starts up, it starts the LeaveAll timer, and sends out a LeaveALL message after the timer times out, so that other GARP entities can re-register all the attribute information on this entity. After that, the entity restarts the LeaveAll timer to begin a new cycle.

II. GVRP port registration mode

GVRP has the following three port registration modes: Normal, Fixed, and Forbidden.

l           Normal: In this mode, a port can dynamically register/deregister a VLAN and propagate the dynamic/static VLAN information.

l           Fixed: In this mode, a port cannot register/deregister a VLAN dynamically. It only propagates static VLAN information. That is, a trunk port only permits the packets of manually configured VLANs in this mode even if you configure the port to permit the packets of all the VLANs.

l           Forbidden: In this mode, a port cannot register/deregister VLANs. It only propagates VLAN 1 information. That is, a trunk port only permits the packets of the default VLAN (namely VLAN 1) in this mode even if you configure the port to permit the packets of all the VLANs.

III. GARP operation procedure

Through the mechanism of GARP, the configuration information on a GARP member will be propagated to the entire switched network. A GARP member can be a terminal workstation or a bridge; it instructs other GARP members to register/unregister its attribute information by declaration/recant, and register/unregister other GARP member's attribute information according to other member's declaration/recant.

The protocol packets of GARP entities use specific multicast MAC addresses as their destination MAC addresses. When receiving these packets, the switch distinguishes them by their destination MAC addresses and delivers them to different GARP application (for example, GVRP) for further processing.

1.1.2  GVRP Packet Format

The GVRP packets are in the following format:

Figure 1-1 Format of GVRP packets

The following table describes the fields of a GVRP packet.

Table 1-1 Description of GVRP packet fields

Field	Description	Value
Protocol ID	Protocol ID	1
Message	Each message consists of two parts: Attribute Type and Attribute List.	—
Attribute Type	Defined by the specific GARP application	The attribute type of GVRP is 0x01.
Attribute List	It contains multiple attributes.	—
Attribute	Each general attribute consists of three parts: Attribute Length, Attribute Event, and Attribute Value. Each LeaveAll attribute consists of two parts: Attribute Length and LeaveAll Event.	—
Attribute Length	The length of the attribute	2 to 255
Attribute Event	The event described by the attribute	0: LeaveAll Event 1: JoinEmpty 2: JoinIn 3: LeaveEmpty 4: LeaveIn 5: Empty
Attribute Value	The value of the attribute	The attribute value of GVRP is the VID.
End Mark	End mark of the GVRP PDU.	—

 

1.1.3  Protocol Specifications

GVRP is defined in IEEE 802.1Q standard.

1.2  GVRP Configuration

The GVRP configuration tasks include configuring the timers, enabling GVRP, and configuring the GVRP port registration mode.

1.2.1  Configuration Prerequisite

The port on which GVRP will be enabled must be set to a trunk port.

1.2.2  Configuration Procedure

Table 1-2 Configuration procedure

Operation	Command	Description
Enter system view	system-view	—
Configure the LeaveAll timer	garp timer leaveall timer-value	Optional By default, the LeaveAll timer is set to 1,000 centiseconds.
Enter Ethernet port view	interface interface-type interface-number	—
Configure the Hold, Join, and Leave timers	garp timer { hold | join | leave } timer-value	Optional By default, the Hold, Join, and Leave timers are set to 10, 20, and 60 centiseconds respectively.
Exit and return to system view	quit	—
Enable GVRP globally	gvrp	Required By default, GVRP is disabled globally.
Enter Ethernet port view	interface interface-type interface-number	—
Enable GVRP on the port	gvrp	Required By default, GVRP is disabled on the port. After you enable GVRP on a trunk port, you cannot change the port to a different type.
Configure GVRP port registration mode	gvrp registration { fixed | forbidden | normal }	Optional You can choose one of the three modes. By default, GVRP port registration mode is normal.

 

The timeout ranges of the timers vary depending on the timeout values you set for other timers. If you want to set the timeout time of a timer to a value out of the current range, you can set the timeout time of the associated timer to another value to change the timeout range of this timer.

The following table describes the relations between the timers:

Table 1-3 Relations between the timers

Timer	Lower threshold	Upper threshold
Hold	10 centiseconds	This upper threshold is less than or equal to one-half of the timeout time of the Join timer. You can change the threshold by changing the timeout time of the Join timer.
Join	This lower threshold is greater than or equal to twice the timeout time of the Hold timer. You can change the threshold by changing the timeout time of the Hold timer.	This upper threshold is less than one-half of the timeout time of the Leave timer. You can change the threshold by changing the timeout time of the Leave timer.
Leave	This lower threshold is greater than twice the timeout time of the Join timer. You can change the threshold by changing the timeout time of the Join timer.	This upper threshold is less than the timeout time of the LeaveAll timer. You can change the threshold by changing the timeout time of the LeaveAll timer.
LeaveAll	This lower threshold is greater than the timeout time of the Leave timer. You can change threshold by changing the timeout time of the Leave timer.	32,765 centiseconds

 

1.3  Displaying and Debugging GVRP

After the above configuration, you can use the display command in any view to display the configuration information and operating status of GVRP/GARP, and thus verify your configuration. You can use the reset command in user view to clear GARP statistics.

Table 1-4 Display and debug GVRP

Operation	Command	Description
Display GARP statistics	display garp statistics [ interface interface-list ]	The display command can be executed in any view.
Display the settings of the GARP timers	display garp timer [ interface interface-list ]
Display GVRP statistics	display gvrp statistics [ interface interface-list ]
Display the global GVRP status	display gvrp status
Clear GARP statistics	reset garp statistics [ interface interface-list ]	The reset command can be executed in user view.

 

1.4  GVRP Configuration Example

1.4.1  Network requirements

You need to enable GVRP on the switches to enable dynamic VLAN information registration and update between the switches.

1.4.2  Network diagram

Figure 1-2 Network diagram for GVRP configuration

1.4.3  Configuration procedure

l           Configure switch A.

# Enable GVRP globally.

<H3C> system-view

[H3C] gvrp

GVRP is enabled globally.

# Configure Ethernet1/0/1 to be a trunk port and to permit the packets of all the VLANs.

[H3C] interface Ethernet 1/0/1

[H3C-Ethernet1/0/1] port link-type trunk

[H3C-Ethernet1/0/1] port trunk permit vlan all

# Enable GVRP on the trunk port.

[H3C-Ethernet1/0/1] gvrp

GVRP is enabled on port Ethernet1/0/1.

l           Configure switch B.

# Enable GVRP globally.

<H3C> system-view

[H3C] gvrp

GVRP is enabled globally.

# Configure Ethernet1/0/2 to be a trunk port and to permit the packets of all the VLANs.

[H3C] interface Ethernet 1/0/2

[H3C-Ethernet1/0/2] port link-type trunk

[H3C-Ethernet1/0/2] port trunk permit vlan all

# Enable GVRP on the trunk port.

[H3C-Ethernet1/0/2] gvrp

GVRP is enabled on port Ethernet1/0/2.