Inbound failover is critical to maintain the continued connection of remote traffic to application (mail, VoIP, Citrix, email, web, ftp, etc.) servers hosted on your LAN. Inbound traffic is more difficult to failover because all Internet services use different IP addresses. There are three ways to avoid changing the IP addresses of your local servers:

1. Dynamic DNS is used in addition to automatic failover and only works if inbound traffic resolves to the host name of the application server instead of directly to its static IP address. The host name in turn resolves to the static IP address of the application server. When the primary connection fails, the host name automatically resolves to the IP addresses of the backup connection. DDNS is provided for free or a nominal charge by DDNS providers. There is no Internet standard and most DDNS providers only support host names that are extensions of their own domain name (e.g., customer.ddns.com). Remote users are disconnected when the primary connection drops and can only reconnect after the DDNS server is updated. DDNS is most effective when all remote users share the the same DDNS server. Otherwise, the length of the changeover depends on how long it takes the DNS change to propagate throughout the Internet.
2. IP Failover transfers the IP address assigned to one connection over to another. The failover appliance switches to another connection when one goes down, establishing a VPN tunnel to your ISP who redirects the IP’s assigned at that connection to the VPN tunnel. Within seconds, the inbound traffic flows through the VPN tunnel instead of the lost connection.
3. Shared IP failover, provided by Skyway, is by far the simplest and most efficient of all failover solutions. Shared IP tunnels the same IP address block over two or more internet connections and when one connection goes down, our failover appliance simply routes all traffic through the alternate connection(s).

Skyway is one of the very few companies capable of Shared IP failover. We can supply your WAN connections or work with connection(s) provided by other ISP’s.

Skyway and our Value-Added Partners support many traffic-management devices and security/VPN appliances (e.g., Astrocom, SonicWall, Fortigate, Mikrotik, etc.) capable of failover and bonding.

Failover appliances can use Policy Routing to manage traffic on multiple WAN connections. For example, a Mikrotik Routerboard 750GL has four wide area network (WAN) ports for connecting multiple broadband connections to a local area network (LAN) and can be configured to separate the outgoing WAN traffic based on policy routing statements. If the IP traffic matches particular criteria (i.e. protocol, port number or particular destination IP) then the outbound traffic is directed up one of the WAN interfaces.

Companies typically segregate highly interactive or latency-sensitive applications like VoIP, VPN or Gaming from from bulk data transfers like email, ftp and http. Alternatively, they might segregate private traffic from public traffic for better security and to prevent public traffic from introducing instability into the less resilient private traffic. Skyway tags and separates the traffic based on a variety of metrics including IP Addresses, Type of Service (TOS) bits, Protocol and Port ranges.

The Mikrotik pings an IP address at the other end of each broadband connection to confirm they are operational. If pings are lost, and that loss exceeds a certain threshold, then the WAN interface is declared down and the Mikrotik fails outbound traffic over to the other broadband connection. The Mikrotik continues sending pings until the “down” interface responds and at that time the Mikrotik begins using both broadband connections again.

Most failover appliances prioritize outgoing traffic based on how it is tagged but have no control over inbound traffic.

Skyway uses failover appliances that integrate with Skyway’s network equipment, allowing us to prioritize both outbound and inbound traffic both before and after failover.