Table of Contents

Chapter 1 Auto Detect Configuration. 1-1

1.1 Introduction to the Auto Detect Function. 1-1

1.1.1 Configuring the Auto Detect Function. 1-1

1.1.2 Displaying Auto Detect Configuration. 1-1

1.1.3 Auto Detect Configuration Example. 1-2

Chapter 2 Auto Detect Implementation. 2-1

2.1 Introduction. 2-1

2.2 Auto Detect Implementation in Static Routing. 2-1

2.2.1 Configuring the Auto Detect Function for a Static Route. 2-1

2.2.2 Configuration Example. 2-2

2.3 Auto Detect Implementation in VRRP. 2-3

2.3.1 Configuring the Auto Detect Function for VRRP. 2-3

2.3.2 Configuration Example. 2-4

2.4 Auto Detect Implementation in VLAN Interface Backup. 2-5

2.4.1 Configuring the Auto Detect Function for VLAN Interface Backup. 2-6

2.4.2 Configuration Example. 2-6

 

Chapter 1  Auto Detect Configuration

1.1  Introduction to the Auto Detect Function

The auto detect function uses ICMP request/reply packets to test the connectivity of a network regularly.

The auto detect function is carried out through detecting groups. A detecting group comprises of a group of the IP addresses to be detected. As the states of detecting groups indicate network state, they can be used to locate network problems in time and trigger network devices to take proper measures against network problems.

1.1.1  Configuring the Auto Detect Function

Table 1-1 Configure the auto detect function

Operation	Command	Description
Enter system view	system-view	—
Create a detecting group and enter detecting group view	detect-group group-number	Required
Add an IP address to be detected to the detecting group	detect-list list-number ip address ip-address [ nexthop ip-address ]	Required
Specify how the detecting result is generated	option [ and | or ]	Optional By default, the and keyword is specified.
Set the detecting interval	timer loop seconds	Optional By default, the detecting interval is 15 seconds.
Set the maximum number of retries during a detecting operation	retry retry-times	Optional By default, the maximum number of retries is 2.
Set the detecting timeout time	timer wait seconds	Optional By default, the detecting timeout time is 2 seconds.

 

1.1.2  Displaying Auto Detect Configuration

After the above-mentioned configuration, you can use the display command in any view to view the auto detect configuration, so as to verify configuration result.

Table 1-2 Display auto detect configuration

Operation	Command	Description
Display the configuration of a detecting group	display detect-group [ group-number ]	The display command can be executed in any view.

 

1.1.3  Auto Detect Configuration Example

I. Network requirements

l           Create detecting group 10 on Switch A and add two IP addresses, 10.1.1.4 and 192.168.2.2, to it to test the reachability to the two IP addresses.

l           Specify to return reachable as the detecting result if one of the two IP addresses is reachable, that is, specify the or keyword for the option command.

l           Set the detecting interval to 60 seconds; the maximum number of retries to 3, and the timeout time to 3 seconds.

II. Network diagram

Figure 1-1 Network diagram for auto detect configuration

III. Configuration procedure

# Enter system view.

<H3C> system-view

# Create detecting group 10.

[H3C] detect-group 10

# Specify to detect the IP address of 10.1.1.4, taking the IP address of 192.168.1.2 as the next hop and setting the detecting number to 1.

[H3C-detect-group-10] detect-list 1 ip address 10.1.1.4 nexthop 192.168.1.2

# Specify to detect the IP address of 192.168.2.2, setting the detecting number to 2.

[H3C-detect-group-10] detect-list 2 ip address 192.168.2.2

# Specify to return reachable as the detecting result if one of the two IP addresses is reachable.

[H3C-detect-group-10] option or

# Set the detecting interval to 60 seconds.

[H3C-detect-group-10] timer loop 60

# Set the maximum number of retries during a detecting operation to 3.

[H3C-detect-group-10] retry 3

# The IP addresses in the detecting group are detected after 3 seconds the last detecting operation is performed.

[H3C-detect-group-10] timer wait 3

[H3C-detect-group-10] quit

[H3C]

 

Chapter 2  Auto Detect Implementation

2.1  Introduction

The results of auto detect operations (reachable or unreachable) can be used to trigger other functions, such as:

l           Static routing

l           Virtual router redundancy protocol (VRRP)

l           Interface backup

l           Packet redirection

You can utilize a single detecting group simultaneously in multiple implementations mentioned above.

 

 

2.2  Auto Detect Implementation in Static Routing

By binding a detecting group to a static route, you can control the validity of a static route according to auto detect results as follows:

l           Enable the static route when the result of the detecting group is reachable.

l           Disable the static route when the result of the detecting group is unreachable.

2.2.1  Configuring the Auto Detect Function for a Static Route

 

 

Table 2-1 Configure the auto detect function for a static route

Operation	Command	Description
Enter system view	system-view	—
Bind a detecting group to a static route	ip route-static ip-address { mask | mask-length } { interface-type interface-number | next-hop } [ preference preference-value ] [ reject | blackhole ] detect-group group-number	Required

 

2.2.2  Configuration Example

I. Network requirements

l           Create detecting group 8 on Switch A. to detect the reachability of the IP address 10.1.1.4/24, with 192.168.1.2/24 as the next hop, and the detecting number set to 1.

l           Configure a static route between Switch A and Switch B.

l           Enable the static route when the result of detecting group 8 is reachable.

II. Network diagram

Figure 2-1 Network diagram for implementing the auto detect function in static routing

III. Configuration procedure

l           Configure Switch A.

# Enter system view.

<H3C> system-view

# Create detecting group 8.

[H3C] detect-group 8

# Detect the reachability of 10.1.1.4/24, with 192.168.1.2/24 as the next hop, and the detecting number set to 1.

[H3C-detect-group-8] detect-list 1 ip address 10.1.1.4 nexthop 192.168.1.2

[H3C-detect-group-8] quit

# Enable the static route when the detecting group is reachable. Disable the static route when the detecting group is unreachable.

[H3C] ip route-static 10.1.1.4 24 192.168.1.2 detect-group 8

2.3  Auto Detect Implementation in VRRP

 

 

You can control the priorities of VRRP backup groups according to auto detect results to enable automatic switch between the master and the backup switch as follows:

l           Decrease the priority of a VRRP backup group when the result of the detecting group is unreachable.

l           Resume the priority of a VRRP backup group when the result of the detecting group is reachable.

2.3.1  Configuring the Auto Detect Function for VRRP

 

 

Table 2-2 Configure the auto detect function for VRRP

Operation	Command	Description
Enter system view	system-view	—
Enter VLAN interface view	interface vlan-interface vlan-id	—
Enable the auto detect function for VRRP	Vrrp vrid virtual-router-id track detect-group group-number [ reduced value-reduced ]	Required

 

2.3.2  Configuration Example

I. Network requirements

l           Switch B and switch D form VRRP backup group 1, whose virtual IP address is 192.168.1.10.

l           Packets sourced from Switch A and destined for Switch C is forwarded by Switch B under normal situations.

l           When the connection between Switch B and Switch C fails, Switch D becomes the Master in backup group 1 automatically and the link from Switch D to Switch C, the secondary link, is enabled.

II. Network diagram

Figure 2-2 Network diagram for implementing the auto detect function in VRRP

III. Configuration procedure

l           Configure Switch B.

# Create detecting group 9.

<H3C> system-view

[H3C] detect-group 9

# Specify to detect the reachability of the IP address 10.1.1.4/24, setting the detect number to 1.

[H3C-detect-group-9] detect-list 1 ip address 10.1.1.4

[H3C-detect-group-9] quit

# Assign an IP address to VLAN 1 interface.

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] ip address 192.168.1.2 24

# Enable VRRP on VLAN 1 interface and assign a virtual IP address to the backup group.

[H3C-Vlan-interface1] vrrp vrid 1 virtual-ip 192.168.1.10

# Set the backup group priority of switch B to 110, and specify to decrease the priority by 20 when the result of detecting group 9 is unreachable.

[H3C-Vlan-interface1] vrrp vrid 1 priority 110

[H3C-Vlan-interface1] vrrp vrid 1 track detect-group 9 reduced 20

l           Configure Switch D.

# Assign an IP address to VLAN 1 interface.

<H3C> system-view

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] ip address 192.168.1.3 24

# Enable VRRP on VLAN 1 interface and assign a virtual IP address to the backup group.

[H3C-Vlan-interface1] vrrp vrid 1 virtual-ip 192.168.1.10

# Set the backup group priority of Switch D to 100.

[H3C-Vlan-interface1] vrrp vrid 1 priority 100

2.4  Auto Detect Implementation in VLAN Interface Backup

The interface backup function is used to back up VLAN interfaces by using the auto detect function. For two VLAN interfaces configured with the same destination device, you can configure them to be the primary interface and the secondary interface. The latter is enabled automatically when the primary fails, so as to ensure the connectivity. In this case, the auto detect function is implemented as follows:

l           In normal situations (that is, when the result of the detecting group is reachable), the secondary VLAN interface is down and packets are transmitted through the primary VLAN interface.

l           When the link between the primary VLAN interface and the destination operates improperly (that is, the result of the detecting group is unreachable), the system shuts down the primary VLAN interface and enables the secondary VLAN interface.

l           When the link between the primary VLAN interface and the destination recovers (that is, the result of the detecting group becomes reachable again), the system enables the primary VLAN interface and shuts down the secondary VLAN interface again.

2.4.1  Configuring the Auto Detect Function for VLAN Interface Backup

 

 

Table 2-3 Configure the auto detect function for VLAN interface backup

Operation	Command	Description
Enter system view	system-view	—
Enter VLAN interface view	interface vlan-interface vlan_id	—
Enable the auto detect function to implement VLAN interface backup	standby detect-group group-number	Required This operation is only needed on the secondary VLAN interface.

 

2.4.2  Configuration Example

I. Network requirements

l           Configure a static route between Switch C and Switch A.

l           Create detecting group 10 on Switch A to detect the connectivity between Switch B and Switch C.

l           Configure VLAN 1 interface to be the primary interface, which is enabled when the result of detecting group 10 is reachable.

l           Configure VLAN 2 interface to be the secondary interface, which is enabled when the result of the detecting group 10 is unreachable.

l           Make sure the routes between Switch A, Switch B, and Switch C are reachable; and those between Switch A, Switch D, and Switch C are also reachable.

II. Network diagram

Figure 2-3 Network diagram for VLAN interface backup

III. Configuration procedure

l           Configure Switch C.

# Enter system view.

<H3C> system-view

# Configure a static route to VLAN interface 1 on Switch A as the primary route, with the IP address of 10.1.1.3/24 as the next hop.

[H3C] ip route-static 192.168.1.1 24 10.1.1.3

# Configure a static route to VLAN interface 2 on Switch A as the secondary route, with the IP address of 20.1.1.3/24 as the next hop.

[H3C] ip route-static 192.168.2.1 24 20.1.1.3

l           Configure Switch A.

# Enter system view.

<H3C> system-view

# Assign an IP address to VLAN 1 interface.

[H3C] interface vlan-interface 1

[H3C-Vlan-interface1] ip address 192.168.1.1 24

[H3C-Vlan-interface1] quit

# Add port Ethernet1/0/2 to VLAN 2.

[H3C] vlan 2

[H3C-vlan2] port ethernet1/0/2

[H3C-vlan2] quit

# Assign an IP address to VLAN 2 interface.

[H3C] interface vlan-interface 2

[H3C-Vlan-interface2] ip address 192.168.2.1 24

[H3C-Vlan-interface2] quit

# Create auto detecting group 10.

[H3C] detect-group 10

# Add the IP address of 10.1.1.4 to detecting group 10 to detect the reachability of the IP address, with the IP address of 192.168.1.2 as the next hop, and the detecting number set to 1.

[H3C-detect-group-10] detect-list 1 ip address 10.1.1.4 nexthop 192.168.1.2

[H3C-detect-group-10] quit

# Specify to enable VLAN 2 interface when the result of detecting group 10 is unreachable.

[H3C] interface vlan-interface 2

[H3C-Vlan-interface2] standby detect-group 10