Uplink Configuration
26.5 Uplink Preferences and Switching
SCALANCE W1750D UI
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Configuration Manual, 02/2018, C79000-G8976-C451-02
In the CLI
To configure uplink preemption:
(scalance)(config)# uplink
(scalance)(uplink)# preemption
(scalance)(uplink)# end
(scalance)# commit apply
26.5.4
Switching Uplinks Based on VPN and Internet Availability
The default priority for uplink switchover is Ethernet and then 3G/4G. The AP can switch to
the lower-priority uplink if the current uplink is down.
Switching Uplinks Based on VPN Status
SCALANCE W supports switching uplinks based on the VPN status when deploying multiple
uplinks (Ethernet, 3G/4G, and Wi-Fi). When VPN is used with multiple backhaul options, the
AP switches to an uplink connection based on the VPN connection status, instead of only
using the Ethernet or the physical backhaul link.
The following configuration conditions apply to uplink switching:
●
If the current uplink is Ethernet and the VPN connection is down, the AP tries to
reconnect to VPN. The retry time depends on the fast failover configuration and the
primary or backup VPN tunnel. If this fails, the AP waits for the VPN failover timeout and
selects a different uplink such as 3G/4G or Wi-Fi.
●
l If the current uplink is 3G or Wi-Fi, and Ethernet has a physical link, the AP periodically
suspends user traffic to try and connect to the VPN on the Ethernet. If the AP succeeds,
the AP switches to Ethernet. If the AP does not succeed, it restores the VPN connection
to the current uplink.
Uplink switching based on VPN status is automatically enabled if VPN is configured on the
AP. However, you can specify the duration in the VPN failover timeout text box to wait for an
uplink switch. By default, this duration is set to 180 seconds. The AP monitors the VPN
status and when the VPN connection is not available for 3 minutes, the uplink switches to
another available connection (if a low-priority uplink is detected and the uplink preference is
set to none). When VPN failover timeout is set to 0, uplink does not switch over.
When uplink switching based on the Internet availability is enabled, the uplink switching
based on VPN failover is automatically disabled.