Example for Configuring Dual-Link Cold Backup
Service Requirements
An enterprise uses two APs to deploy WLAN area A to provide WLAN services. The enterprise requires that dual-link backup be used to improve data transmission reliability.
Networking Requirements
- AC networking mode: Layer 2 networking in bypass mode
- DHCP deployment mode: The switch functions as a DHCP server to assign IP addresses to APs and STAs.
- Service data forwarding mode: direct forwarding
Data Planning
Item |
Data |
|---|---|
Management VLANs for APs |
VLAN 100 |
Service VLAN for STAs |
VLAN 101 |
DHCP server |
Switch functions as the DHCP server for the APs and STAs. STAs' gateway: 10.23.101.1/24 APs' gateway: 10.23.100.1/24 |
IP address pool for APs |
10.23.100.4-10.23.100.254/24 |
IP address pool for STAs |
10.23.101.2-10.23.101.254/24 |
AC's source interface |
VLANIF 100 |
Management IP address of AC1 |
VLANIF 100: 10.23.100.2/24 |
Management IP address of AC2 |
VLANIF 100: 10.23.100.3/24 |
AP group |
|
Regulatory domain profile |
|
SSID profile |
|
Security profile |
|
VAP profile |
|
AP system profile |
|
Configuration Roadmap
- Set up connections between AC1, AC2, and other network devices. Configure the switch as a DHCP server to assign IP addresses to APs and STAs.
- Configure AC1 as the active AC and configure basic WLAN services on AC1.
- Configure AC2 as the standby AC and configure basic WLAN services on AC2. Ensure that service configurations on AC1 and AC2 are the same.
- Configure dual-link backup on the active AC first and then on the standby AC. When dual-link backup is enabled, all APs are restarted. With dual-link backup enabled, the standby AC will replace the active AC to manage APs if the CAPWAP tunnel between the active AC and APs is disconnected.
Configuration Notes
- No ACK mechanism is provided for multicast packet transmission on air interfaces. In addition, wireless links are unstable. To ensure stable transmission of multicast packets, they are usually sent at low rates. If a large number of such multicast packets are sent from the network side, the air interfaces may be congested. You are advised to configure multicast packet suppression to reduce impact of a large number of low-rate multicast packets on the wireless network. Exercise caution when configuring the rate limit; otherwise, the multicast services may be affected.
- In direct forwarding mode, you are advised to configure multicast packet suppression on switch interfaces connected to APs.
- In tunnel forwarding mode, you are advised to configure multicast packet suppression in traffic profiles of the AC.
Configure port isolation on the interfaces of the device directly connected to APs. If port isolation is not configured and direct forwarding is used, a large number of unnecessary broadcast packets may be generated in the VLAN, blocking the network and degrading user experience.
In tunnel forwarding mode, the management VLAN and service VLAN cannot be the same. Only packets from the management VLAN are transmitted between the AC and APs. Packets from the service VLAN are not allowed between the AC and APs.
Dual-link backup does not support DHCP information backup. If the active AC functions as a DHCP server to assign IP addresses to APs and STAs, the APs and STAs need to obtain IP addresses again upon a failure of the active AC. Therefore, the switch is recommended as a DHCP server. If the AC must be used as the DHCP server, manually plan address pools with different IP address ranges on the active and standby ACs to prevent repeated IP address allocation.
Procedure
- Configure the switch and AC to enable the AC to communicate with the APs.
# On the switch, create VLAN 100 and VLAN 101. VLAN 100 is used as the management VLAN and VLAN 101 is used as the service VLAN. Set the link type of GE0/0/1 and GE0/0/4 that connect the switch to the APs to trunk and the PVID of the two interfaces to 100, and configure the interfaces to allow packets in VLAN 100 and VLAN 101 to pass. Set the link type of GE0/0/2 and GE0/0/3 on the switch to trunk, and configure the interfaces to allow packets in VLAN 100 to pass.
<HUAWEI> system-view [HUAWEI] sysname Switch [Switch] vlan batch 100 101 [Switch] interface gigabitethernet 0/0/1 [Switch-GigabitEthernet0/0/1] port link-type trunk [Switch-GigabitEthernet0/0/1] port trunk pvid vlan 100 [Switch-GigabitEthernet0/0/1] port trunk allow-pass vlan 100 to 101 [Switch-GigabitEthernet0/0/1] port-isolate enable [Switch-GigabitEthernet0/0/1] quit [Switch] interface gigabitethernet 0/0/4 [Switch-GigabitEthernet0/0/4] port link-type trunk [Switch-GigabitEthernet0/0/4] port trunk pvid vlan 100 [Switch-GigabitEthernet0/0/4] port trunk allow-pass vlan 100 to 101 [Switch-GigabitEthernet0/0/4] port-isolate enable [Switch-GigabitEthernet0/0/4] quit [Switch] interface gigabitethernet 0/0/2 [Switch-GigabitEthernet0/0/2] port link-type trunk [Switch-GigabitEthernet0/0/2] port trunk allow-pass vlan 100 [Switch-GigabitEthernet0/0/2] quit [Switch] interface gigabitethernet 0/0/3 [Switch-GigabitEthernet0/0/3] port link-type trunk [Switch-GigabitEthernet0/0/3] port trunk allow-pass vlan 100 [Switch-GigabitEthernet0/0/3] quit
# Add GE0/0/1 on AC1 connected to the switch to VLAN 100.
<HUAWEI> system-view [HUAWEI] sysname AC1 [AC1] vlan batch 100 101 [AC1] interface gigabitethernet 0/0/1 [AC1-GigabitEthernet0/0/1] port link-type trunk [AC1-GigabitEthernet0/0/1] port trunk allow-pass vlan 100 [AC1-GigabitEthernet0/0/1] quit
# Add GE0/0/1 on AC2 connected to the switch to VLAN 100.
<HUAWEI> system-view [HUAWEI] sysname AC2 [AC2] vlan batch 100 101 [AC2] interface gigabitethernet 0/0/1 [AC2-GigabitEthernet0/0/1] port link-type trunk [AC2-GigabitEthernet0/0/1] port trunk allow-pass vlan 100 [AC2-GigabitEthernet0/0/1] quit
- Configure the DHCP function on the switch to assign IP addresses to APs and STAs.Configure the DNS server as required. The common methods are as follows:
- In interface address pool scenarios, run the dhcp server dns-list ip-address &<1-8> command in the VLANIF interface view.
- In global address pool scenarios, run the dns-list ip-address &<1-8> command in the IP address pool view.
# Configure VLANIF 100 to use the interface address pool to assign IP addresses to APs.
[Switch] dhcp enable [Switch] interface vlanif 100 [Switch-Vlanif100] ip address 10.23.100.1 255.255.255.0 [Switch-Vlanif100] dhcp select interface [Switch-Vlanif100] dhcp server excluded-ip-address 10.23.100.2 10.23.100.3 [Switch-Vlanif100] quit
# Configure VLANIF 101 to use the interface address pool to assign IP addresses to STAs.
[Switch] interface vlanif 101 [Switch-Vlanif101] ip address 10.23.101.1 255.255.255.0 [Switch-Vlanif101] dhcp select interface [Switch-Vlanif101] quit
- Configure basic WLAN services on AC1.
- Configure APs to go online.
# Create an AP group to which the APs with the same configuration can be added.
[AC1] wlan [AC1-wlan-view] ap-group name ap-group1 [AC1-wlan-ap-group-ap-group1] quit
# Create a regulatory domain profile, configure the AC country code in the profile, and apply the profile to the AP group.
[AC1-wlan-view] regulatory-domain-profile name default [AC1-wlan-regulate-domain-default] country-code cn [AC1-wlan-regulate-domain-default] quit [AC1-wlan-view] ap-group name ap-group1 [AC1-wlan-ap-group-ap-group1] regulatory-domain-profile default Warning: Modifying the country code will clear channel, power and antenna gain configurations of the radio and reset the AP. Continue?[Y/N]:y [AC1-wlan-ap-group-ap-group1] quit [AC1-wlan-view] quit
# Configure the AC's source interface.
[AC1] interface vlanif 100 [AC1-Vlanif100] ip address 10.23.100.2 255.255.255.0 [AC1-Vlanif100] quit [AC1] capwap source interface vlanif 100
# Import the APs offline on the AC and add the APs to AP group ap-group1. Assume that the APs' MAC addresses are 00e0-fc76-e360 and 00e0-fc74-9640, respectively. Configure names for the APs based on the APs' deployment locations, so that you can know where the APs are deployed from their names. For example, name the AP with the MAC address 00e0-fc76-e360 as area_1 if it is deployed in area 1, and name the AP with the MAC address 00e0-fc74-9640 as area_2 if it is deployed in area 2.The ap auth-mode command sets the AP authentication mode to MAC address authentication by default. If the default settings are retained, you do not need to run the ap auth-mode mac-auth command.
In this example, the AP5030DN is used and has two radios: radio 0 and radio 1.
[AC1] wlan [AC1-wlan-view] ap auth-mode mac-auth [AC1-wlan-view] ap-id 0 ap-mac 00e0-fc76-e360 [AC1-wlan-ap-0] ap-name area_1 [AC1-wlan-ap-0] ap-group ap-group1 Warning: This operation may cause AP reset. If the country code changes, it will clear channel, power and antenna gain configuration s of the radio, Whether to continue? [Y/N]:y [AC1-wlan-ap-0] quit [AC1-wlan-view] ap-id 1 ap-mac 00e0-fc74-9640 [AC1-wlan-ap-1] ap-name area_2 [AC1-wlan-ap-1] ap-group ap-group1 Warning: This operation may cause AP reset. If the country code changes, it will clear channel, power and antenna gain configuration s of the radio, Whether to continue? [Y/N]:y [AC1-wlan-ap-1] quit
# After the APs are powered on, run the display ap all command to check the AP states. If the State field displays nor, the APs have gone online.
[AC1-wlan-view] display ap all Total AP information: nor : normal [2] Extra information: P : insufficient power supply -------------------------------------------------------------------------------------------------- ID MAC Name Group IP Type State STA Uptime ExtraInfo -------------------------------------------------------------------------------------------------- 0 00e0-fc76-e360 area_1 ap-group1 10.23.100.253 AP5030DN nor 0 10S - 1 00e0-fc74-9640 area_2 ap-group1 10.23.100.254 AP5030DN nor 0 10S - -------------------------------------------------------------------------------------------------- Total: 2 - Configure WLAN service parameters.# Create security profile wlan-net and configure a security policy in the profile.
In this example, the security policy is set to WPA-WPA2+PSK+AES and the password to a1234567. In actual situations, configure the security policy according to service requirements.
[AC1-wlan-view] security-profile name wlan-net [AC1-wlan-sec-prof-wlan-net] security wpa-wpa2 psk pass-phrase a1234567 aes [AC1-wlan-sec-prof-wlan-net] quit
# Create SSID profile wlan-net and set the SSID name to wlan-net.
[AC1-wlan-view] ssid-profile name wlan-net [AC1-wlan-ssid-prof-wlan-net] ssid wlan-net [AC1-wlan-ssid-prof-wlan-net] quit
# Create VAP profile wlan-net, set the data forwarding mode and service VLAN, and apply the security profile and SSID profile to the VAP profile.
[AC1-wlan-view] vap-profile name wlan-net [AC1-wlan-vap-prof-wlan-net] forward-mode direct-forward [AC1-wlan-vap-prof-wlan-net] service-vlan vlan-id 101 [AC1-wlan-vap-prof-wlan-net] security-profile wlan-net [AC1-wlan-vap-prof-wlan-net] ssid-profile wlan-net [AC1-wlan-vap-prof-wlan-net] quit
# Bind VAP profile wlan-net to the AP group and apply the profile to radio 0 and radio 1 of the AP.
[AC1-wlan-view] ap-group name ap-group1 [AC1-wlan-ap-group-ap-group1] vap-profile wlan-net wlan 1 radio 0 [AC1-wlan-ap-group-ap-group1] vap-profile wlan-net wlan 1 radio 1 [AC1-wlan-ap-group-ap-group1] quit
- Configure APs to go online.
- Configure basic WLAN services on AC2.
# Configure basic parameters for AC2 according to the configurations of AC1.
# Configure the source interface of AC2.
[AC2] interface vlanif 100 [AC2-Vlanif100] ip address 10.23.100.3 255.255.255.0 [AC2-Vlanif100] quit [AC2] capwap source interface vlanif 100 [AC2] wlan
- Configure dual-link backup on AC1 and AC2.
# On AC1, specify the IP addresses of the primary and backup ACs.
[AC1-wlan-view] ap-system-profile name wlan-net [AC1-wlan-ap-system-prof-wlan-net] primary-access ip-address 10.23.100.2 [AC1-wlan-ap-system-prof-wlan-net] backup-access ip-address 10.23.100.3 [AC1-wlan-ap-system-prof-wlan-net] quit [AC1-wlan-view] ap-group name ap-group1 [AC1-wlan-ap-group-ap-group1] ap-system-profile wlan-net [AC1-wlan-ap-group-ap-group1] quit [AC1-wlan-view] ac protect enable Warning: This operation maybe cause AP reset, continue?[Y/N]:y
# On AC2, specify the IP addresses of the primary and backup ACs.
[AC2-wlan-view] ap-system-profile name wlan-net [AC2-wlan-ap-system-prof-wlan-net] primary-access ip-address 10.23.100.2 [AC2-wlan-ap-system-prof-wlan-net] backup-access ip-address 10.23.100.3 [AC2-wlan-ap-system-prof-wlan-net] quit [AC2-wlan-view] ap-group name ap-group1 [AC2-wlan-ap-group-ap-group1] ap-system-profile wlan-net [AC2-wlan-ap-group-ap-group1] quit [AC2-wlan-view] ac protect enable Warning: This operation maybe cause AP reset, continue?[Y/N]:y
# Restart the APs on AC1 and AC2 and deliver the dual-link backup configuration to the APs.
[AC1-wlan-view] ap-reset all Warning: Reset AP(s), continue?[Y/N]:y
[AC2-wlan-view] ap-reset all Warning: Reset AP(s), continue?[Y/N]:y
- Verify the configuration.
# Run the display ac protect and display ap-system-profile name wlan-net commands on the active and standby ACs to check dual-link information.
[AC1-wlan-view] display ap-system-profile name wlan-net ------------------------------------------------------------------------------ AC priority : - Protect AC IP address : - Primary AC : 10.23.100.2 Backup AC : 10.23.100.3 ... [AC1-wlan-view] display ac protect ------------------------------------------------------------ Protect state : enable ... ------------------------------------------------------------
[AC2-wlan-view] display ap-system-profile name wlan-net ------------------------------------------------------------------------------ AC priority : - Protect AC IP address : - Primary AC : 10.23.100.2 Backup AC : 10.23.100.3 ... [AC2-wlan-view] display ac protect ------------------------------------------------------------ Protect state : enable ... ------------------------------------------------------------
# When an AP detects a fault on the link connected to AC1, AC2 takes the active role, ensuring service stability.
# Simulate a master AC fault by restarting the master AC to verify the backup configuration. Restart AC1. When an AP detects a fault on the link connected to AC1, AC2 takes the active role, ensuring service stability.Before restarting the AC, run the save command to save the configuration file on the AC to prevent configuration loss after the restart.
# When AC1 is restarted, the AP goes online on AC2. Run the display ap all command on AC2. The command output shows that the AP status changes from standby to normal.
# After AC1 recovers from the restart, an active/standby switchback is triggered. The AP automatically goes online on AC1.
Configuration Files
Switch configuration file
# sysname Switch # vlan batch 100 to 101 # dhcp enable # interface Vlanif100 ip address 10.23.100.1 255.255.255.0 dhcp select interface dhcp server excluded-ip-address 10.23.100.2 10.23.100.3 # interface Vlanif101 ip address 10.23.101.1 255.255.255.0 dhcp select interface # interface GigabitEthernet0/0/1 port link-type trunk port trunk pvid vlan 100 port trunk allow-pass vlan 100 to 101 port-isolate enable group 1 # interface GigabitEthernet0/0/2 port link-type trunk port trunk allow-pass vlan 100 # interface GigabitEthernet0/0/3 port link-type trunk port trunk allow-pass vlan 100 # interface GigabitEthernet0/0/4 port link-type trunk port trunk pvid vlan 100 port trunk allow-pass vlan 100 to 101 port-isolate enable group 1 # return
- AC1 and AC2 have similar configuration files, which are listed in the following table. (Configurations highlighted in bold are the dual-link backup configurations on AC1 and AC2.)
Table 4-52 Configuration files of AC1 and AC2
AC1
AC2
# sysname AC1 # vlan batch 100 to 101 # interface Vlanif100 ip address 10.23.100.2 255.255.255.0 # interface GigabitEthernet0/0/1 port link-type trunk port trunk allow-pass vlan 100 # capwap source interface vlanif100 # wlan ac protect enable security-profile name wlan-net security wpa-wpa2 psk pass-phrase %^%#m"tz0f>~7.[`^6RWdzwCy16hJj/Mc!,}s`X*B]}A%^%# aes ssid-profile name wlan-net ssid wlan-net vap-profile name wlan-net service-vlan vlan-id 101 ssid-profile wlan-net security-profile wlan-net regulatory-domain-profile name default ap-system-profile name wlan-net primary-access ip-address 10.23.100.2 backup-access ip-address 10.23.100.3 ap-group name ap-group1 ap-system-profile wlan-net radio 0 vap-profile wlan-net wlan 1 radio 1 vap-profile wlan-net wlan 1 ap-id 0 type-id 35 ap-mac 00e0-fc76-e360 ap-sn 210235554710CB000042 ap-name area_1 ap-group ap-group1 ap-id 1 type-id 35 ap-mac 00e0-fc74-9640 ap-sn 210235419610D2000097 ap-name area_2 ap-group ap-group1 # return
# sysname AC2 # vlan batch 100 to 101 # interface Vlanif100 ip address 10.23.100.3 255.255.255.0 # interface GigabitEthernet0/0/1 port link-type trunk port trunk allow-pass vlan 100 # capwap source interface vlanif100 # wlan ac protect enable security-profile name wlan-net security wpa-wpa2 psk pass-phrase %^%#m"tz0f>~7.[`^6RWdzwCy16hJj/Mc!,}s`X*B]}A%^%# aes ssid-profile name wlan-net ssid wlan-net vap-profile name wlan-net service-vlan vlan-id 101 ssid-profile wlan-net security-profile wlan-net regulatory-domain-profile name default ap-system-profile name wlan-net primary-access ip-address 10.23.100.2 backup-access ip-address 10.23.100.3 ap-group name ap-group1 ap-system-profile wlan-net radio 0 vap-profile wlan-net wlan 1 radio 1 vap-profile wlan-net wlan 1 ap-id 0 type-id 35 ap-mac 00e0-fc76-e360 ap-sn 210235554710CB000042 ap-name area_1 ap-group ap-group1 ap-id 1 type-id 35 ap-mac 00e0-fc74-9640 ap-sn 210235419610D2000097 ap-name area_2 ap-group ap-group1 # return