Chapter 1 Setting the Port State Change Delay
The port state change delay configuration was added to Release 2107P07.
During a short period after you connect your switch to another device, the connecting port may go up and down frequently due to hardware compatibility, resulting in service interruption.
To avoid situations like this, you may introduce a port state change delay.
Caution:
The port state change delay takes effect when the port goes down but not when the port goes up.
Follow these steps to set the port state change delay:
To do … | Use the command … | Remarks |
Enter system view | system-view | — |
Enter Ethernet interface view | interface interface-type interface-number | — |
Set the port state change delay | link-delay delay-time | Required Defaults to 0, which indicates that no delay is introduced. |
Display the information about the port with the link-delay command configured | display link-delay | Available in any view |
The delay configured in this way does not take effect for ports in DLDP down state.
Syntax
link-delay delay-time
undo link-delay
View
Ethernet port view
Parameters
delay-time: Port state change delay to be set. This argument is in the range 2 to 10 (in seconds).
Description
Use the link-delay command to set the port state change delay.
Use the undo link-delay command to restore the default.
By default, the port state change delay is 0 seconds, that is, the port state changes without any delay.
During a short period after you connect your switch to another device, the connecting port may go up and down frequently due to hardware compatibility, resulting in service interruption.
To avoid situations like this, you may set a port state change delay.
l The port state change delay takes effect when the port goes down but not when the port goes up.
l The delay configured in this way does not take effect for ports in DLDP down state.
Examples
# Set the port state change delay of Ethernet 1/0/5 to 8 seconds.
<Sysname> system-view
Enter system view, return to user view with Ctrl+Z.
[Sysname] interface Ethernet1/0/5
[Sysname-Ethernet1/0/5] link-delay 8
Syntax
display link-delay
View
Any view
Parameters
None
Description
Use the display link-delay command to display the information about the ports with the link-delay command configured, including the port name and the configured delay.
Related commands: link-delay.
Examples
# Display the information about the ports with the link-delay command configured.
<Sysname> display link-delay
Interface Time Delay
===================== ==============
Ethernet1/0/5 8
Configuration the source IP address of IGMP group-specific queries was added to Release 2107P07.
In an IP multicast network running IGMP, one dedicated multicast device is responsible for sending IGMP general queries, and this router or Layer 3 switch is called the IGMP querier.
However, a Layer 2 multicast switch does not support IGMP, and therefore cannot send general queries by default. By enabling IGMP Snooping querier on a Layer 2 switch in a VLAN where multicast traffic needs to be Layer-2 switched only and no multicast routers are present, the Layer 2 switch will act as a querier to send IGMP general queries, thus allowing multicast forwarding entries to be established and maintained at the data link layer.
Upon receiving an IGMP query with the source IP address 0.0.0.0 on a port, the switch does not enlist that port as a dynamic router port. This may prevent multicast forwarding entries from being correctly created at the data link layer and cause multicast traffic forwarding failure in the end. When a Layer 2 device acts as an IGMP-Snooping querier, to avoid the aforesaid problem, configure a non-all-zero IP address as the source IP address of IGMP queries.
IGMP Snooping querier related configurations include:
l Enabling IGMP Snooping querier,
l Configuring the IGMP query interval, and
l Configuring the source address to be carried in IGMP general and group specific queries.
I. Enabling IGMP Snooping querier
Follow these steps to enable IGMP Snooping querier:
To do... | Use the command... | Remarks |
Enter system view | system-view | — |
Enable IGMP Snooping | igmp-snooping enable | Required By default, IGMP Snooping is disabled. |
Enter VLAN view | vlan vlan-id | — |
Enable IGMP Snooping | igmp-snooping enable | Required By default, IGMP Snooping is disabled. |
Enable IGMP Snooping querier | igmp-snooping querier | Required By default, IGMP Snooping querier is disabled. |
II. Configuring IGMP query interval
Follow these steps to configure IGMP query interval:
To do... | Use the command... | Remarks |
Enter system view | system-view | — |
Enter VLAN view | vlan vlan-id | — |
Configure the IGMP query interval | igmp-snooping query-interval seconds | Optional 60 seconds by default. |
III. Configuring the source address to be carried in IGMP queries
Follow these steps to configure the source address to be carried in IGMP queries:
To do... | Use the command... | Remarks |
Enter system view | system-view | — |
Enter VLAN view | vlan vlan-id | — |
Configure the source IP address of IGMP general queries | igmp-snooping general-query source-ip { current-interface | ip-address } | Optional 0.0.0.0 by default |
Configure the source IP address of IGMP group-specific queries | igmp-snooping special-query source-ip { current-interface | ip-address } | 0.0.0.0 by default |
Command igmp-snooping special-query source-ip was added to Release 2107P07. For the details about the rest commands about IGMP Snooping Querier Configuration, please refer to the Command Manual of the switch.
Syntax
igmp-snooping special-query source-ip { current-interface | ip-address }
undo igmp-snooping special-query source-ip
View
VLAN view
Parameters
current-interface: Specifies the IP address of the current VLAN interface as the source address to be carried in IGMP group-specific queries. If the current VLAN interface does not have an IP address, the default IP address 0.0.0.0 will be used as the source IP address of IGMP group-specific queries.
ip-address: Specifies the source address to be carried in IGMP group-specific queries, which can be any legal IP address.
Description
Use the igmp-snooping special-query source-ip command to configure the source address to be carried in IGMP group-specific queries.
Use the undo igmp-snooping special-query source-ip command to restore the default.
By default, the Layer 2 multicast switch sends group-specific query messages with the source IP address of 0.0.0.0.
Related commands: igmp-snooping querier.
Examples
# Configure the switch to send group-specific query messages with the source IP address 2.2.2.2 in VLAN 3.
<Sysname> system-view
System view, return to user view with Ctrl+Z.
[Sysname] igmp-snooping enable
[Sysname] vlan 3
[Sysname-vlan3] igmp-snooping enable
[Sysname-vlan3] igmp-snooping special-query source-ip 2.2.2.2
