Table of Contents

1 GVRP Configuration· 1-1

Introduction to GVRP· 1-1

GARP· 1-1

GVRP· 1-4

Protocols and Standards· 1-4

Configuring GVRP· 1-4

Configuring GVRP Functions· 1-4

Configuring GARP Timers· 1-5

Displaying and Maintaining GVRP· 1-6

GVRP Configuration Examples· 1-7

GVRP Configuration Example I 1-7

GVRP Configuration Example II 1-8

GVRP Configuration Example III 1-9

 

The GARP VLAN Registration Protocol (GVRP) is a GARP application. It functions based on the operating mechanism of GARP to maintain and propagate dynamic VLAN registration information for the GVRP devices on the network.

When configuring GVRP, go to these sections for information you are interested in:

l          Introduction to GVRP

l          Configuring GVRP

l          Displaying and Maintaining GVRP

l          GVRP Configuration Examples

Introduction to GVRP

GARP

The Generic Attribute Registration Protocol (GARP) provides a mechanism that allows participants in a GARP application to distribute, propagate, and register with other participants in a LAN the attributes specific to the GARP application, such as the VLAN or multicast address attribute.

GARP itself does not exist on a device as an entity. GARP-compliant participants are known as GARP applications. One example is GVRP. When a GARP participant is present on a port on your device, the port is regarded as a GARP participant.

GARP messages and timers

1)        GARP messages

A GARP participant exchanges information with other GARP participants by sending the following three types of messages:

l          Join messages to register with other entities its attributes, the attributes received from other GARP application entities, and the attributes manually configured on it.

l          Leave messages to have its attributes deregistered on other devices. A GARP participant also sends Leave messages when it receives Leave messages from other GARP participants or when attributes are manually deregistered on it.

l          LeaveAll messages to deregister all the attributes so that all GARP participants can re-register all attributes with each other. A LeaveAll message is sent upon expiration of a LeaveAll timer, which starts upon the startup of a GARP application entity.

Join messages, Leave messages, and LeaveAll message make sure the reregistration and deregistration of GARP attributes are performed in an orderly way.

Through message exchange, all attribute information that needs registration propagates to all GARP participants on the LAN.

2)        GARP timers

GARP uses the following four timers to set the interval for sending GARP messages:

l          Hold timer –– When a GARP application entity receives the first registration request, it starts a hold timer and collects succeeding requests. When the timer expires, the entity sends all these requests in one Join message. This helps you save bandwidth.

l          Join timer –– A GARP participant sends each Join message at most twice for reliability sake and uses a join timer to set the sending interval. If the first Join message has not been acknowledged before the Join timer expires, the GARP participant sends the second Join message.

l          Leave timer –– Starts upon receipt of a Leave message sent for deregistering some attribute information. If no Join message has been received before this timer expires, the GARP participant removes the attribute information as requested.

l          LeaveAll timer –– Starts when a GARP participant starts. When this timer expires, the entity sends a LeaveAll message so that other participants can re-register its attribute information. Then, a LeaveAll timer starts again.

 

 

Operating mechanism of GARP

The GARP mechanism allows the configuration of a GARP participant to propagate throughout a LAN quickly. In GARP, a GARP participant registers or deregisters its attributes with other participants by making or withdrawing declarations of attributes and at the same time, based on received declarations or withdrawals, handles attributes of other participants. When a port receives an attribute declaration, it registers the attribute; when a port receives an attribute withdrawal, it deregisters the attribute.

GARP participants send protocol data units (PDU) with a particular multicast MAC address as destination. Based on this address, a device can identify to which GVRP application (GVRP for example) a GARP PDU should be delivered.

GARP message format

The following figure illustrates the GARP message format.

Figure 1-1 GARP message format

 

Table 1-1 describes the GARP message fields.

Table 1-1 Description on the GARP message fields

Field	Description	Value
Protocol ID	Protocol identifier for GARP	1
Message	One or multiple messages, each containing an attribute type and an attribute list	––
Attribute Type	Defined by the concerned GARP application	0x01 for GVRP, indicating the VLAN ID attribute
Attribute List	Contains one or multiple attributes	––
Attribute	Consists of an Attribute Length, an Attribute Event, and an Attribute Value	––
Attribute Length	Number of octets occupied by an attribute, inclusive of the attribute length field	2 to 255 (in bytes)
Attribute Event	Event described by the attribute	0: LeaveAll event 1: JoinEmpty event 2: JoinIn event 3: LeaveEmpty event 4: LeaveIn event 5: Empty event
Attribute Value	Attribute value	VLAN ID for GVRP If the Attribute Event is LeaveAll, Attribute Value is omitted.
End Mark	Indicates the end of a GARP PDU	0x00

 

GVRP

GVRP enables a device to propagate local VLAN registration information to other participant devices and dynamically update the VLAN registration information from other devices to its local database about active VLAN members and through which port they can be reached. It thus ensures that all GVRP participants on a bridged LAN maintain the same VLAN registration information. The VLAN registration information propagated by GVRP includes both manually configured local static entries and dynamic entries from other devices.

GVRP provides the following three registration types on a port:

l          Normal –– Enables the port to dynamically register and deregister VLANs, and to propagate both dynamic and static VLAN information.

l          Fixed –– Disables the port to dynamically register and deregister VLANs or propagate information about dynamic VLANs, but allows the port to propagate information about static VLANs. A trunk port with fixed registration type thus allows only manually configured VLANs to pass through even though it is configured to carry all VLANs.

l          Forbidden –– Disables the port to dynamically register and deregister VLANs and to propagate VLAN information except information about VLAN 1. A trunk port with forbidden registration type thus allows only VLAN 1 to pass through even though it is configured to carry all VLANs.

Protocols and Standards

GVRP is described in IEEE 802.1Q.

Configuring GVRP

 

 

Configuring GVRP includes Configuring GVRP Functions and Configuring GARP Timers.

Configuring GVRP Functions

Before enabling GVRP on a port, you must enable GVRP globally.

Follow these steps to configure GVRP functions on a trunk port:

To do…		Use the command…	Remarks
Enter system view		system-view	––
Enable GVRP globally		gvrp	Required Globally disabled by default
Enter Ethernet interface view or port-group view	Enter Ethernet interface view	interface interface-type interface-number	Required Use either command. l      In Ethernet interface view, the subsequent configurations apply to the current port. l      In port group view, the subsequent configurations apply to all ports in the port group. l      In Layer-2 aggregate interface view, the subsequent configurations apply to the Layer-2 aggregate interface and all its member ports.
	Enter Layer-2 aggregate interface view	interface bridge-aggregation interface-number
	Enter port-group view	port-group manual port-group-name
Enable GVRP on the port		gvrp	Required Disabled by default
Configure the GVRP registration mode on the port		gvrp registration { fixed | forbidden | normal }	Optional The default is normal.

 

 

Configuring GARP Timers

Among the four GARP timers, the LeaveAll timer is configured in system view and takes effect on all ports, while the other three are configured on a port basis.

Follow these steps to configure GARP timers:

To do…		Use the command…	Remarks
Enter system view		system-view	––
Configure the GARP LeaveAll timer		garp timer leaveall timer-value	Optional The default is 1000 centiseconds.
Enter Ethernet interface view or port-group view	Enter Ethernet interface view	interface interface-type interface-number	Required Use either command. l      In Ethernet interface view, the subsequent configurations apply to the current port. l      In port group view, the subsequent configurations apply to all ports in the port group. l      In Layer-2 aggregate interface view, the subsequent configurations apply to the Layer-2 aggregate interface and all its member ports.
	Enter Layer-2 aggregate interface view	interface bridge-aggregation interface-number
	Enter port-group view	port-group manual port-group-name
Configure the hold timer, join timer, and leave timer		garp timer { hold | join | leave } timer-value	Optional The default is 10 centiseconds for the hold timer, 20 centiseconds for the join timer, and 60 centiseconds for the leave timer.

 

When configuring GARP timers, note that their values are dependent on each other and must be a multiple of five centiseconds. If the value range for a timer is not desired, you may change it by tuning the value of another related timer as shown in the following table:

Table 1-2 Dependencies of GARP timers

Timer	Lower limit	Upper limit
Hold	10 centiseconds	Not greater than half of the join timer setting
Join	Not less than two times the hold timer setting	Less than half of the leave timer setting
Leave	Greater than two times the join timer setting	Less than the LeaveAll timer setting
LeaveAll	Greater than the leave timer setting	32765 centiseconds

 

 

Displaying and Maintaining GVRP

To do…	Use the command…	Remarks
Display statistics about GARP	display garp statistics [ interface interface-list ]	Available in any view
Display GARP timers for specified or all ports	display garp timer [ interface interface-list ]	Available in any view
Display the local VLAN information maintained by GVRP	display gvrp local-vlan interface interface-type interface-number	Available in any view
Display the current GVRP state	display gvrp state interface interface-type interface-number vlan vlan-id	Available in any view
Display statistics about GVRP	display gvrp statistics [ interface interface-list ]	Available in any view
Display the global GVRP state	display gvrp status	Available in any view
Display the information about dynamic VLAN operations performed on a port	display gvrp vlan-operation interface interface-type interface-number	Available in any view
Clear the GARP statistics	reset garp statistics [ interface interface-list ]	Available in user view

 

GVRP Configuration Examples

GVRP Configuration Example I

Network requirements

Configure GVRP for dynamic VLAN information registration and update among devices, adopting the normal registration mode on ports.

Network diagram

Figure 1-2 Network diagram for GVRP configuration

 

Configuration procedure

1)        Configure Device A

# Enable GVRP globally.

<DeviceA> system-view

[DeviceA] gvrp

# Configure port GigabitEthernet 2/0/1 as a trunk port, allowing all VLANs to pass through.

[DeviceA] interface GigabitEthernet 2/0/1

[DeviceA-GigabitEthernet2/0/1] port link-type trunk

[DeviceA-GigabitEthernet2/0/1] port trunk permit vlan all

# Enable GVRP on GigabitEthernet 2/0/1, the trunk port.

[DeviceA-GigabitEthernet2/0/1] gvrp

[DeviceA-GigabitEthernet2/0/1] quit

# Create VLAN 2 (a static VLAN).

[DeviceA] vlan 2

2)        Configure Device B

# Enable GVRP globally.

<DeviceB> system-view

[DeviceB] gvrp

# Configure port GigabitEthernet 2/0/1 as a trunk port, allowing all VLANs to pass through.

[DeviceB] interface GigabitEthernet 2/0/1

[DeviceB-GigabitEthernet2/0/1] port link-type trunk

[DeviceB-GigabitEthernet2/0/1] port trunk permit vlan all

# Enable GVRP on GigabitEthernet 2/0/1, the trunk port.

[DeviceB-GigabitEthernet2/0/1] gvrp

[DeviceB-GigabitEthernet2/0/1] quit

# Create VLAN 3 (a static VLAN).

[DeviceB] vlan 3

3)        Verify the configuration

# Display dynamic VLAN information on Device A.

[DeviceA] display vlan dynamic

 Now, the following dynamic VLAN exist(s):

  3

# Display dynamic VLAN information on Device B.

[DeviceB] display vlan dynamic

 Now, the following dynamic VLAN exist(s):

  2

GVRP Configuration Example II

Network requirements

Configure GVRP for dynamic VLAN information registration and update among devices. Specify fixed GVRP registration on Device A and normal GVRP registration on Device B.

Network diagram

Figure 1-3 Network diagram for GVRP configuration

 

Configuration procedure

1)        Configure Device A

# Enable GVRP globally.

<DeviceA> system-view

[DeviceA] gvrp

# Configure port GigabitEthernet 2/0/1 as a trunk port, allowing all VLANs to pass through.

[DeviceA] interface GigabitEthernet 2/0/1

[DeviceA-GigabitEthernet2/0/1] port link-type trunk

[DeviceA-GigabitEthernet2/0/1] port trunk permit vlan all

# Enable GVRP on GigabitEthernet 2/0/1.

[DeviceA-GigabitEthernet2/0/1] gvrp

# Set the GVRP registration type to fixed on the port.

[DeviceA-GigabitEthernet2/0/1] gvrp registration fixed

[DeviceA-GigabitEthernet2/0/1] quit

# Create VLAN 2 (a static VLAN).

[DeviceA] vlan 2

2)        Configure Device B

# Enable GVRP globally.

<DeviceB> system-view

[DeviceB] gvrp

# Configure port GigabitEthernet 2/0/1 as a trunk port, allowing all VLANs to pass through.

[DeviceB] interface GigabitEthernet 2/0/1

[DeviceB-GigabitEthernet2/0/1] port link-type trunk

[DeviceB-GigabitEthernet2/0/1] port trunk permit vlan all

# Enable GVRP on GigabitEthernet 2/0/1.

[DeviceB-GigabitEthernet2/0/1] gvrp

[DeviceB-GigabitEthernet2/0/1] quit

# Create VLAN 3 (a static VLAN).

[Sysname] vlan 3

3)        Verify the configuration

# Display dynamic VLAN information on Device A.

[DeviceA] display vlan dynamic

 No dynamic vlans exist!

# Display dynamic VLAN information on Device B.

[DeviceB] display vlan dynamic

 Now, the following dynamic VLAN exist(s):

  2

GVRP Configuration Example III

Network requirements

To prevent dynamic VLAN information registration and update among devices, set the GVRP registration mode to forbidden on Device A and normal on Device B.

Network diagram

Figure 1-4 Network diagram for GVRP configuration

 

Configuration procedure

1)        Configure Device A

# Enable GVRP globally.

<DeviceA> system-view

[DeviceA] gvrp

# Configure port GigabitEthernet 2/0/1 as a trunk port, allowing all VLANs to pass through.

[DeviceA] interface GigabitEthernet 2/0/1

[DeviceA-GigabitEthernet2/0/1] port link-type trunk

[DeviceA-GigabitEthernet2/0/1] port trunk permit vlan all

# Enable GVRP on GigabitEthernet 2/0/1.

[DeviceA-GigabitEthernet2/0/1] gvrp

# Set the GVRP registration type to forbidden on the port.

[DeviceA-GigabitEthernet2/0/1] gvrp registration forbidden

[DeviceA-GigabitEthernet2/0/1] quit

# Create VLAN 2 (a static VLAN).

[DeviceA] vlan 2

2)        Configure Device B

# Enable GVRP globally.

<DeviceB> system-view

[DeviceB] gvrp

# Configure port GigabitEthernet 2/0/1 as a trunk port, allowing all VLANs to pass through.

[DeviceB] interface GigabitEthernet 2/0/1

[DeviceB-GigabitEthernet2/0/1] port link-type trunk

[DeviceB-GigabitEthernet2/0/1] port trunk permit vlan all

# Enable GVRP on GigabitEthernet 2/0/1.

[DeviceB-GigabitEthernet2/0/1] gvrp

[DeviceB-GigabitEthernet2/0/1] quit

# Create VLAN 3 (a static VLAN).

[DeviceB] vlan 3

3)        Verify the configuration

# Display dynamic VLAN information on Device A.

[DeviceA] display vlan dynamic

 No dynamic vlans exist!

# Display dynamic VLAN information on Device B.

[DeviceB] display vlan dynamic

 No dynamic vlans exist!