Use the WLR - Advanced page to configure Layer 1 link detection and Layer 3 ping detection to determine the availability of a WAN link. Each method has configurable up and down interval times between keepalive attempts and the number of attempts before a link is considered available or unavailable. 

  1. Choose Network > WAN Failover > Advanced. 
    The following figure shows the WAN interface configured with the primary VLAN host.


    The following figure shows the WAN interface configured with the secondary VLAN host.


  2. Configure settings using the information in the table below. When you have finished configuring settings, click Submit to make your changes take effect.

    WLR - Advanced Configuration Parameters

    ItemDescription

    Link Detection Module

    Configure Link Detection Module settings:

    Up Link Timer (seconds)

    Enter the number of seconds between keepalive attempts when determining if a link is back up or leave the default value.

    Up Link Attempts

    Enter the number of consecutive successful keep alive attempts before a WAN link is considered back up or leave the default value.

    Down Link Timer (seconds)

    Enter the number of seconds between keepalive attempts when determining if a link has gone down or leave the default value.

    Down Link Attempts

    Enter the number of consecutive failed keepalive attempts before a WAN link is considered down or leave the default value.

    Link Detection Delay (seconds)

    Specifies the number of seconds to wait before making switchover decisions when the link first comes up.

    There are certain WAN types whose Data Link Layer takes time to establish. These types include Frame Relay over T1. If the time to establish exceeds the Link and Ping Detection Down timers, WLR considers the WAN link unavailable and switches over to the backup link. If revertive mode is disabled and the link becomes available soon after, WLR will not assign it as the active link.

    This parameter can be tuned so that WLR waits for the link to come up before marking an interface as down and switching over to another link. This delay occurs as the system starts or after a switchover, when the module restarts. This should not affect switchover time under working conditions.

    Link Detection Delay only applies to non-PPP Frame Relay WAN types. It should be set to the maximum acceptable time for a Frame Relay link to be established. The range is 1 to 180 seconds. The default is 90 seconds.

    Ping Detection Module

    Configure Ping Detection Module settings:

    Up Ping Timer (seconds)

    Enter the time interval in seconds before the module sends an Internet Control Message Protocol (ICMP) echo request packet on a physically up link to the Ping Host.

    Up Ping Attempts

    Enter the number consecutive responses for ICMP requests from the Ping Host on a previously down link before the link can be declared as up.


    Down Ping Timer (seconds)

    Enter the time interval in seconds before the module sends an ICMP request on a down link with physically up interface.

    Down Ping Attempts

    Enter the number of consecutive ICMP requests with no responses from the Ping Host on a physically up interface with a previously up link status.

    Ping Response Timeout (milliseconds)Enter the maximum time (in milliseconds) the Ping Detection Module should wait, for the ping response to return. The default time is 60 milliseconds.

    Ping Detection Settings

    Configure Ping Detection Settings.

    Enable Primary Ping Detection

    Select the Enable Primary Ping Detection checkbox to activate the layer 3 ICMP-based ping detection mechanism. WLR will send periodic keepalive pings to the configured host to monitor the status of the WAN Link.

    Primary Ping Type

    Select the Primary Ping Type (either IPv4 or IPv6) based on whether the host is using IPv4 or IPv6.

    If you are using IPv4 hosts, configure the link for IPv4. If you are using IPv6 hosts, configure the link for IPv6.

    Note: Ping type selector is enforced only for ambiguous configurations where the system cannot determine if IPv4 or IPv6 ping is desired due to blank hosts or FQDN hosts on a dual-stack link.

    Primary Ping Host 1/2/3Enter the primary host IPs to which periodical keepalive pings should be sent. You can give up to 3 host IPs. If all three hosts are left unspecified, the default gateway becomes the ping host by default.

    Enable Secondary Ping Detection

    Select the Enable Secondary Ping Detection checkbox to enable a secondary ping detection mechanism for WLR to send periodic keepalive pings.

    Secondary Ping Type

    Select the Secondary Ping Type (either IPv4 or IPv6) based on whether the host is using IPv4 or IPv6.

    If you are using IPv4 hosts, configure the link for IPv4. If you are using IPv6 hosts, configure the link for IPv6.

    Note: Ping type selector is enforced only for ambiguous configurations where the system cannot determine if IPv4 or IPv6 ping is desired due to blank hosts or FQDN hosts on a dual-stack link.

    Secondary Ping Host 1/2/3Enter the secondary host IPs to which periodical keepalive pings should be sent. You can give up to 3 host IPs. If all three hosts are left unspecified, the default gateway becomes the ping host by default.

    Ping Detection Hosts Settings

    Configure Ping Detection Hosts settings for an interface.

    WAN Interface

    Select the interface from the drop-down list.

    Note

    If the ping host is already configured, then the following parameters will populate automatically.

    Enable ping detectionSelect the checkbox to enable ping detection for the interface.
    Ping TypeSelect the checkbox to to enable the ping host IP address: IPv4 or IPv6.
    Ping Host 1, 2, and 3

    Enter the host name in the Ping Host(s) field and click Add.

    Note
    • If you configure more than one host for a link, then all hosts are pinged simultaneously.
    • If all Ping Hosts fail to respond to the configured number of consecutive attempts, then that link is considered "failed". However, if even one host is responding, the link is still considered active.
    • Hosts for a link can be all IP addresses, all FQDNs, or a combination of the two.
    • Hosts for one link must be all IPv4 or all IPv6 for that link. (Note: IPv4 on one link and IPv6 on other link is acceptable.)
    • FQDNs must have A (IPv4) or AAAA (IPv6) records.
    • To use IPv6 hosts, be sure to configure the link for IPv6.
    • TTL determines the frequency of the DNS lookup for an FQDN.
    • IPv4/IPv6 ping type selector will be enforced only for ambiguous configurations where the system cannot determine if IPv4 or IPv6 ping would be desired due to blank or FQDN hosts on a dual-stack link.