Connection Failover
WinRoute allows for definition of connection failover (secondary connection). This alternate connection is enabled automatically whenever a dropout of the primary Internet connection is detected. Functionality of the primary connection is tested by sending of ICMP Echo Requests (PING) to selected computers. When WinRoute finds out that the primary connection is recovered again, the alternate connection is disabled and the primary one is established automatically.
Any network interface or dial connection defined in WinRoute can be used as an alternate connection (see chapter Interfaces). Traffic rules permitting or denying relevant communication through the alternate connection must be defined. This means that a network connected to the alternate interface must be added to the Destination section of all rules defining traffic going out to the Internet through the primary connection.
For details on traffic rules refer to chapter Definition of Custom Traffic Rules.
Example: Primary connection used for traffic going out to the Internet is performed by a network adapter (labeled as Internet in WinRoute). A Dial-up Connection interface will be used for the alternate connection. We want to deny the Telnet service in direction from the local network to the Internet.
To meet these requirements, the following rules are set. Two destination items are specified for each rule: network connected to the Internet interface (primary connection) and network connected to the Dial-up Connection interface (alternate connection).
- Forbid Telnet connection to Telnet in direction from the local network to the Internet will be forbidden.
- NAT translation of source IP addresses will be performed for connections from the local network to the Internet (shared Internet connection).
- Firewall traffic the WinRoute host will be allowed to connect to the Internet (NAT is not necessary since this host has its proper IP address).
Notes:
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Traffic rules must be defined by the moment when Connection Failover Setup (see below) is enabled, otherwise the connection will not function properly.
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Use the Default outgoing interface option in the NAT rule to ensure that the source IP address in packets going from the local network to the Internet is always resolved to the appropriate IP address (i.e. to the IP address of either the primary or alternate interface accordingly to which one is used at that moment).
To specify an IP address for NAT, two independent rules must be defined one for the primary and the other for an alternate connection.
Connection Failover Setup
Secondary Use the Connection failover tab in Configuration / Interfaces to define a secondary connection.
Enable automatic connection failover
Use this option to enable/disable connection failover.
Current connection
This item informs users on which connection is currently active:
- Primary primary connection (in a green field)
- Secondary alternate (secondary) connection (in a purple field)
Note: Current connections can be switched any time. To view the current status click on the Refresh button (at the bottom of the Connection failover tab).
Probe hosts
Use this entry to specify IP address(es) of at least one computer (or a router, etc.). WinRoute will test availability of specified IP address(es) in regular intervals. If at least one of the tested devices is available, the primary connection is considered as functioning.
Note:
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Connection failover is enabled only if at least one probe host is specified (WinRoute is not able to detect fails of the primary connection unless at least one probe host is defined).
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Probe hosts must be represented by computers or network devices which are permanently running (servers, routers, etc.). Workstations which are running only a few hours per day are irrelevant as probe hosts.
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Probe hosts must not block ICMP Echo Requests (PING) since such requests are used to test availability of these hosts otherwise the hosts will be always considered as unavailable.
Primary connection
Parameters of the primary Internet connection. The connection can be defined as follows:
- network interface with a default gateway
- dial-up connection
Only interfaces and dial-up connections defined through the Interfaces tab are available in the Interface entry (see chapter Interfaces).
Default settings (default gateway and a corresponding interface) are detected in the operating system after WinRoute installation, or when the Enable automatic connection failover option is enabled the first time. This can be also be achieved by clicking on the Detect button.
If no default gateway is defined in the operating system (i.e. when the primary connection is performed by a dial-up which is currently hung-up), a connection cannot be detected automatically the primary connection must be set by hand.
Alternate connection
Use this section to set parameters for an alternate internet connection which will be established in case that a primary connection dropout is detected. The alternate connection can be defined as a network interface with a default gateway or as a dial-up connection (like for the primary connection).
Note: The same adapter as for the primary connection can be used, however, the default gateway must be different. This way we can be sure that a different router in the same network (subnet) will be used when the primary connection is dropped out.
Dial-up Use
The following issues must be taken into consideration if a dial-up is used for the primary and/or the alternate connection:
- Connection failover is relevant only if performed by a permanent connection (using a network adapter or a permanently connected dial-up). If an on-demand dial-up (or a dial-up connection dialed by hand) was used for the primary connection, the alternate connection would be established automatically after each hang-up of the primary connection.
- If a dial-up is used for alternate connection, it is not important whether this line is dialed on demand WinRoute will dial and hang up the line whenever needed.
However, problems can be caused by the Hang-up if idle option whenever the alternate line is disconnected automatically, WinRoute will not dial it again (unless the primary connection is recovered and then fails again).
For these reasons we recommend you to set dial-up parameters as follows:
- for the primary connection persistent connection
- for the alternate connection manual dialing
