display gvrp state

Function

The display gvrp state command displays information about the GVRP state machine.

Format

display gvrp state interface interface-type interface-number vlan vlan-id

Parameters

Parameter	Description	Value
interface interface-type interface-number	Displays information about the GVRP state machine of the specified interface. interface-type specifies the type of an interface. interface-number specifies the number of an interface.	-
vlan vlan-id	Displays information about the state machine of the specified VLAN.	The value is an integer that ranges from 2 to 4094.

Views

All views

Default Level

1: Monitoring level

Usage Guidelines

The GVRP function has two types of state machines: Applicant state machine and Registrar state machine.

An applicant implements declaration of attributes. If no message is lost during transmission, an applicant can ensure that all registrars have registered an attribute after it sends a Join message or receives a JoinIn message. To ensure reliable transmission of messages, the applicant needs to send two Join messages or send a Join message and receive a JoinIn message to confirm that all registrars have registered an attribute. Therefore, a simple counter is used. The counter starts from 0 and increases by 1 every time the applicant sends a Join message or receives a JoinIn message. The maximum value of the counter is 2. If the applicant receives a JoinEmpty, Empty, Leave, or LeaveAll message, the counter is reset to 0. This indicates that the applicant can send PDUs only when the value of the counter is smaller than 2.

The Join timer controls the interval for sending Join messages, but not every attribute has its own Join timer. A GVRP participant uses a Join timer. The value of the Join timer must be long enough to ensure that all the attributes can be packaged in a message and transmitted in a declaration.

Anxious applicants
Depending on the value of the applicant counter, an applicant may be in either of the following states:
- V (very anxious): The value of the counter is 0, indicating that the applicant does not send a Join message or receive a JoinIn message.
- A (anxious): The value of the counter is 1, indicating that no message is lost and all the registrars have registered the attribute.
- Q (quiet): The value of the counter is 2, indicating that the applicant does not need to send Join messages.
Members and observers

The preceding states are applicable to normal situations. In special cases, for example, when some terminals do not need to send registration messages and only need to retain all the GARP state machines, these terminals must be separated from other entities. Therefore, the concept of member and observer is introduced. A member refers to an entity that tries to declare or retain an attribute value or an entity that has not sent a Leave message yet. An observer refers to an entity that traces the states of attributes but does not declare attributes.
Multiple entities may actively join or leave the same attribute. To minimize the number of Join or Leave messages in this situation, members are classified into active members and passive members. Therefore, the following states are introduced:
- A: Active member
- P: Passive member
- O: Observer

In addition, when an active member must send a Leave message to cancel a declaration, the active member enters the leaving state. Considering all these states, the state machine of an applicant has multiple state combinations, as shown in the following table.

State Combination	Very Anxious	Anxious	Quiet	Leaving
Active Member	VA	AA	QA	LA
Passive Member	VP	AP	QP	-
Observer	VO	AO	QO	LO

When a passive member needs to cancel a declaration, it can switch to the observer state. Therefore, the leaving passive member state does not exist.

A registrar has a Leave timer and three states: IN (attribute registered), MTR (attribute deregistered), and LV (attribute being deregistered). If a registrar in LV state does not receive the declaration of an attribute within the timeout interval of the Leave timer, the registrar enters the MTR state.

A registrar changes to different states depending on the received message:

When receiving a Join message, the registrar changes to the IN state.
When receiving a Leave or LeaveAll message, the registrar changes from the IN state to the LV state and starts the Leave timer. If the registrar is not in IN state, it does not change its state after receiving a Leave or LeaveAll message.
The registrar does not change its state after receiving an Empty message.

Example

# Display information about the GVRP state machine.

<HUAWEI> display gvrp state interface gigabitethernet 0/0/1 vlan 100 
    GVRP state of VLAN 100 on port GigabitEthernet0/0/1

         Applicant state machine :    VP
         Registrar state machine :    MTR

**Table 1** Description of the display gvrp state command output
Item	Description
Applicant state machine	State machine of the applicant.
Registrar state machine	State machine of the registrar.