Contents

Configuring dual-link backup· 1

About dual-link backup· 1

Restrictions and guidelines: Dual-link backup configuration· 1

Dual-link backup tasks at a glance· 2

Setting AP connection priority and specifying a backup AC· 2

Configuring master CAPWAP tunnel preemption· 2

Dual-link backup configuration examples· 3

Example: Configuring dual-link backup· 3

Configuring WLAN uplink detection· 5

About WLAN uplink detection· 5

Restrictions and guidelines: WLAN uplink detection· 5

Configuring WLAN uplink detection· 5

WLAN uplink detection configuration examples· 5

Example: Configuring WLAN uplink detection· 5

 

Configuring dual-link backup

About dual-link backup

Dual-link backup enables two ACs to back up each other to reduce risks of service interruption caused by single-AC failures.

With dual-link backup enabled, an AP establishes a master CAPWAP tunnel and a backup CAPWAP tunnel with the master AC and the backup AC, respectively. The master and backup ACs cannot detect each other's link state in real time. When the backup AC takes over traffic forwarding upon a master AC failure, temporary communication interruption occurs. When the failed master AC recovers, the master CAPWAP tunnel preemption feature determines the master CAPWAP tunnel based on the AP connection priority.

Dual-link backup is applicable to networks that are service continuity insensitive.

Figure 1 Network diagram for dual-link backup

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Restrictions and guidelines: Dual-link backup configuration

For the dual-link backup feature to function correctly, configure auto AP or manual APs on the two ACs. The manual AP configuration must be identical on both ACs. For more information, see managing APs in AP and WT Management Configuration Guide.

You can configure APs by using the following methods:

·     Configure APs one by one in AP view.

·     Assign APs to an AP group and configure the AP group in AP group view.

·     Configure all APs in global configuration view.

For an AP, the settings made in these views for the same parameter take effect in descending order of AP view, AP group view, and global configuration view.

Dual-link backup tasks at a glance

To configure dual-link backup, perform the following tasks:

1.     Setting AP connection priority and specifying a backup AC

2.     (Optional.) Configuring master CAPWAP tunnel preemption

Setting AP connection priority and specifying a backup AC

About this task

Set a higher AP connection priority for the master AC to ensure that APs can associate with the master AC first.

After an AP establishes a CAPWAP tunnel with the master AC, the AP will establish a backup CAPWAP tunnel with the specified backup AC.

Procedure

1.     Enter system view.

system-view

2.     Enter AP view or AP group view.

¡     Enter AP view.

wlan ap ap-name

¡     Enter AP group view.

wlan ap-group group-name

3.     Set the AP connection priority.

priority priority

By default:

¡     In AP view, an AP uses the configuration in AP group view.

¡     In AP group view, the AP connection priority is 4.

4.     Specify a backup AC.

backup-ac { ip ipv4-address | ipv6 ipv6-address }

By default:

¡     In AP view, an AP uses the configuration in AP group view.

¡     In AP group view, no backup AC is specified.

Configuring master CAPWAP tunnel preemption

About this task

This feature enables a backup CAPWAP tunnel to become a master tunnel after the specified delay time if the backup AC has higher AP connection priority than the master AC.

Procedure

1.     Enter system view.

system-view

2.     (Optional.) Set the delay time for backup-to-master switchover.

wlan backup-ac switch-delay time

The default setting is 5 seconds.

3.     Enter AP view, AP group view, or global configuration view.

¡     Enter AP view.

wlan ap ap-name

¡     Enter AP group view.

wlan ap-group group-name

¡     Enter global configuration view.

wlan global-configuration

4.     Configure master CAPWAP tunnel preemption.

wlan tunnel-preempt { disable | enable }

By default:

¡     In AP view, an AP uses the configuration in AP group view. If no configuration exists in AP group view, the AP uses the configuration in global configuration view.

¡     In AP group view, an AP uses the configuration in global configuration view.

¡     In global configuration view, master CAPWAP tunnel preemption is disabled.

Dual-link backup configuration examples

Example: Configuring dual-link backup

Network configuration

As shown in Figure 2, configure AC 1 to act as the master AC and AC 2 as the backup AC. When AC 1 fails and AC 2 takes over, the AP can communicate through AC 2. Configure the master CAPWAP tunnel preemption feature on the two ACs so that the AP reconnects to AC 1 when AC 1 recovers.

Figure 2 Network diagram

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Procedure

1.     Configure AC 1:

# Create VLAN-interface 1 and assign an IP address to it.

<AC1> system-view

[AC1] interface vlan-interface 1

[AC1-Vlan-interface1] ip address 10.1.1.1 24

[AC1-Vlan-interface1] quit

# Create an AP named ap1, and specify the AP model and serial ID. Set the AP connection priority to 7.

[AC1] wlan ap ap1 model WA4320i-ACN

[AC1-wlan-ap-ap1] serial-id 210235A1BSC123000050

[AC1-wlan-ap-ap1] priority 7

# Specify a backup AC.

[AC1-wlan-ap-ap1] backup-ac ip 11.1.1.1

# Enable master CAPWAP tunnel preemption.

[AC1-wlan-ap-ap1] wlan tunnel-preempt enable

[AC1-wlan-ap-ap1] quit

2.     Configure AC 2:

# Create VLAN-interface 1 and assign an IP address to it.

<AC2> system-view

[AC2] interface Vlan-interface 1

[AC2-Vlan-interface1] ip address 11.1.1.1 24

[AC2-Vlan-interface1] quit

# Create an AP named ap1, and specify the AP model and serial ID. Set the AP connection priority to 5.

[AC2] wlan ap ap1 model WA4320i-ACN

[AC2-wlan-ap-ap1] serial-id 210235A1BSC123000050

[AC2-wlan-ap-ap1] priority 5

# Specify a backup AC.

[AC2-wlan-ap-ap1] backup-ac ip 10.1.1.1

# Enable master CAPWAP tunnel preemption.

[AC2-wlan-ap-ap1] wlan tunnel-preempt enable

[AC2-wlan-ap-ap1] quit

Verifying the configuration

# Get the AP online on AC 1. (Details not shown.)

# Shut down VLAN-interface 1 on AC 1 and wait no longer than 3 minutes, during which service interruption occurs. (Details not shown.)

# Verify that the AP comes online on AC 2 and the AP state is R/M on AC 2. (Details not shown.)

# Bring up VLAN-interface 1 on AC 1. (Details not shown.)

# Verify that the AP comes online on AC 1 again and the AP state is R/M on AC 1 and R/B in AC 2. (Details not shown.)

Configuring WLAN uplink detection

About WLAN uplink detection

When the uplink of an AC fails, clients cannot access external networks through the APs that are connected to the AC. WLAN uplink detection associates the uplink state of an AC with the radio state of the connected APs. When the uplink fails, the AC disables the radios of the APs. When the uplink recovers, the AC enables the radios of the APs. The association ensures that clients can associate with APs connected to another AC when the uplink of an AC fails.

This feature collaborates with a detection module and the Track module to function.

·     When the track entry is in Positive state, the AC enables the radios of the connected APs.

·     When the track entry is in Negative state, the AC disables the radios of the connected APs.

·     When the track entry is in Invalid state, the AC does not change the radio state of the connected APs.

For more information about the track module, see "Configuring Track."

Restrictions and guidelines: WLAN uplink detection

For the WLAN uplink detection feature to function correctly, configure a detection module to detect the uplink state, and associate a track entry with the detection module. For more information, see "Configuring Track."

Configuring WLAN uplink detection

1.     Enter system view.

system-view

2.     Associate a track entry with the WLAN uplink detection feature.

wlan uplink track track-entry-number

By default, WLAN uplink detection is not associated with any track entry.

WLAN uplink detection configuration examples

Example: Configuring WLAN uplink detection

Network configuration

As shown in Figure 3, use an NQA operation to test the reachability of each AC's uplink. Configure WLAN uplink detection on each AC so that clients can associate with the AP connected to another AC when the uplink of an AC fails.

Figure 3 Network diagram

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Procedure

1.     Configure AC 1:

# Create an ICMP echo operation.

<AC1> system-view

[AC1] nqa entry admin test

[AC1-nqa-admin-test] type icmp-echo

# Specify 10.1.1.1 as the destination IP address of ICMP echo requests.

[AC1-nqa-admin-test-icmp-echo] destination ip 10.1.1.1

# Configure the ICMP echo operation to repeat every 1000 milliseconds.

[AC1-nqa-admin-test-icmp-echo] frequency 1000

# Create reaction entry 1. If the number of consecutive probe failures reaches 5, collaboration is triggered.

[AC1-nqa-admin-test-icmp-echo] reaction 1 checked-element probe-fail threshold-type consecutive 5 action-type trigger-only

[AC1-nqa-admin-test-icmp-echo] quit

# Start the ICMP echo operation.

[AC1] nqa schedule admin test start-time now lifetime forever

# Configure track entry 1, and associate it with reaction entry 1 of the NQA operation (with administrator admin and operation tag test).

[AC1] track 1 nqa entry admin test reaction 1

[AC1-track-1] quit

# Associate track entry 1 with WLAN uplink detection.

[AC1] wlan uplink track 1

[AC1] quit

2.     Configure AC 2:

# Create an ICMP echo operation.

<AC2> system-view

[AC2] nqa entry admin test

[AC2-nqa-admin-test] type icmp-echo

# Specify 11.1.1.1 as the destination IP address of ICMP echo requests.

[AC2-nqa-admin-test-icmp-echo] destination ip 11.1.1.1

# Create reaction entry 1. If the number of consecutive probe failures reaches 5, collaboration is triggered.

[AC2-nqa-admin-test-icmp-echo] reaction 1 checked-element probe-fail threshold-type consecutive 5 action-type trigger-only

[AC2-nqa-admin-test-icmp-echo] quit

# Start the ICMP echo operation.

[AC2] nqa schedule admin test start-time now lifetime forever

# Configure track entry 1, and associate it with reaction entry 1 of the NQA operation (with administrator admin and operation tag test).

[AC2] track 1 nqa entry admin test reaction 1

# Associate track entry 1 with WLAN uplink detection.

[AC2] wlan uplink track 1

[AC2] quit

Verifying the configuration

This example uses AC 1 to verify the configuration.

1.     Verify that the radio state of AP 1 is Up when the state of track entry 1 is Positive:

# Display information about track entry 1.

<AC1> display track 1

Track ID: 1

  State: Positive

  Duration: 0 days 1 hours 5 minutes 48 seconds

  Notification delay: Positive 0, Negative 0 (in seconds)

  Tracked object:

    NQA entry: admin test

    Reaction: 1

# Display detailed information about AP ap1.

<AC1> display wlan ap name ap1 verbose

AP name                       : ap1

AP ID                         : 1

AP group name                 : default-group

State                         : Run

Backup Type                   : Master

Online time                   : 0 days 2 hours 25 minutes 12 seconds

System up time                : 0 days 1 hours 22 minutes 12 seconds

Model                         : WA4320i-ACN

Region code                   : US

Region code lock              : Disable

Serial ID                     : 210235A1BSC123000050

MAC address                   : 83D5-AB43-67FF

IP address                    : 1.1.1.2

H/W version                   : Ver.C

S/W version                   : V700R001B62D001

Boot version                  : 1.01

Description                   : wtp1

Priority                      : 4

Echo interval                 : 10 seconds

Statistics report interval    : 50 seconds

Jumbo frame value             : Disabled

MAC type                      : Local MAC & Split MAC

Tunnel mode                   : Local Bridging & 802.3 Frame & Native Frame

Discovery type                : DHCP

Retransmission count          : 3

Retransmission interval       : 5 seconds

Firmware upgrade              : Enabled

Sent control packets          : 1

Received control packets      : 1

Connection count              : 1

Backup Ipv4                   : Not configured

Backup Ipv6                   : Not configured

Tunnel encryption             : Disabled

LED mode                      : Normal

Radio 1:

    Basic BSSID               : N/A

    Admin state               : Up

    Radio type                : 802.11n(5GHz)

    Antenna type              : internal

    Client dot11ac-only       : Disabled

    Client dot11n-only        : Disabled

    Channel band-width        : 20/40MHz

    Secondary channel offset  : SCB

    Short GI for 20MHz        : Supported

    Short GI for 40MHz        : Supported

    A-MSDU                    : Enabled

    A-MPDU                    : Enabled

    LDPC                      : Not Supported

    STBC                      : Supported

    Operational HT MCS Set:

        Mandatory             : Not configured

        Supported             : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,

                                10, 11, 12, 13, 14, 15

        Multicast             : Not configured

    Channel                   : 64(auto)

    Max power                 : 13 dBm

    Operational rate:

        Mandatory             : 6, 12, 24 Mbps

        Supported             : 9, 18, 36, 48, 54 Mbps

        Multicast             : 24 Mbps

        Disabled              : Not configured

    Distance                  : 1 km

    ANI                       : Enabled

    Fragmentation threshold   : 2346 bytes

    Beacon interval           : 100 TU

    Protection threshold      : 2346 bytes

    Long retry threshold      : 4

    Short retry threshold     : 7

    Maximum rx duration       : 2000 ms

    Noise Floor               : 0 dBm

    Smart antenna             : Enabled

    Smart antenna policy      : Auto

Radio 2:

    Basic BSSID               : N/A

    Admin state               : Up

    Radio type                : 802.11b

    Antenna type              : internal

    Channel                   : 5(auto)

    Max power                 : 20 dBm

    Preamble type             : Short

    Operational rate:

        Mandatory             : 1, 2 Mbps

        Multicast             : Auto

        Supported             : 5.5, 11 Mbps

        Disabled              : Not configured

    Distance                  : 1 km

    ANI                       : Enabled

    Fragmentation threshold   : 2346 bytes

    Beacon interval           : 100 TU

    Protection threshold      : 2346 bytes

    Long retry threshold      : 4

    Short retry threshold     : 7

    Maximum rx duration       : 2000 ms

    Noise Floor               : 0 dBm

2.     Verify that the radio state of AP 1 is Down when the state of track entry 1 is Negative:

# Display information about track entry 1.

<AC1> display track 1

Track ID: 1

  State: Negative

  Duration: 0 days 2 hours 5 minutes 48 seconds

  Notification delay: Positive 0, Negative 0 (in seconds)

  Tracked object:

    NQA entry: admin test

    Reaction: 1

# Display detailed information about AP ap1.

<AC1> display wlan ap name ap1 verbose

AP name                       : ap1

AP ID                         : 1

AP group name                 : default-group

State                         : Run

Backup Type                   : Master

Online time                   : 0 days 3 hours 25 minutes 12 seconds

System up time                : 0 days 2 hours 22 minutes 12 seconds

Model                         : WA4320i-ACN

Region code                   : US

Region code lock              : Disable

Serial ID                     : 210235A1BSC123000050

MAC address                   : 83D5-AB43-67FF

IP address                    : 1.1.1.2

H/W version                   : Ver.C

S/W version                   : V700R001B62D001

Boot version                  : 1.01

Description                   : wtp1

Priority                      : 4

Echo interval                 : 10 seconds

Statistics report interval    : 50 seconds

Jumbo frame value             : Disabled

MAC type                      : Local MAC & Split MAC

Tunnel mode                   : Local Bridging & 802.3 Frame & Native Frame

Discovery type                : DHCP

Retransmission count          : 3

Retransmission interval       : 5 seconds

Firmware upgrade              : Enabled

Sent control packets          : 1

Received control packets      : 1

Connection count              : 1

Backup Ipv4                   : Not configured

Backup Ipv6                   : Not configured

Tunnel encryption             : Disabled

LED mode                      : Normal

Radio 1:

    Basic BSSID               : N/A

    Admin state               : Down

    Radio type                : 802.11n(5GHz)

    Antenna type              : internal

    Client dot11ac-only       : Disabled

    Client dot11n-only        : Disabled

    Channel band-width        : 20/40MHz

    Secondary channel offset  : SCB

    Short GI for 20MHz        : Supported

    Short GI for 40MHz        : Supported

    A-MSDU                    : Enabled

    A-MPDU                    : Enabled

    LDPC                      : Not Supported

    STBC                      : Supported

    Operational HT MCS Set:

        Mandatory             : Not configured

        Supported             : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,

                                10, 11, 12, 13, 14, 15

        Multicast             : Not configured

    Channel                   : 64(auto)

    Max power                 : 13 dBm

    Operational rate:

        Mandatory             : 6, 12, 24 Mbps

        Supported             : 9, 18, 36, 48, 54 Mbps

        Multicast             : 24 Mbps

        Disabled              : Not configured

    Distance                  : 1 km

    ANI                       : Enabled

    Fragmentation threshold   : 2346 bytes

    Beacon interval           : 100 TU

    Protection threshold      : 2346 bytes

    Long retry threshold      : 4

    Short retry threshold     : 7

    Maximum rx duration       : 2000 ms

    Noise Floor               : 0 dBm

    Smart antenna             : Enabled

    Smart antenna policy      : Auto

Radio 2:

    Basic BSSID               : N/A

    Admin state               : Down

    Radio type                : 802.11b

    Antenna type              : internal

    Channel                   : 5(auto)

    Max power                 : 20 dBm

    Preamble type             : Short

    Operational rate:

        Mandatory             : 1, 2 Mbps

        Multicast             : Auto

        Supported             : 5.5, 11 Mbps

        Disabled              : Not configured

    Distance                  : 1 km

    ANI                       : Enabled

    Fragmentation threshold   : 2346 bytes

    Beacon interval           : 100 TU

    Protection threshold      : 2346 bytes

    Long retry threshold      : 4

    Short retry threshold     : 7

    Maximum rx duration       : 2000 ms

    Noise Floor               : 0 dBm