6.3 Connection Failover
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## 6.3 Connection Failover

WinRoute allows guarantee Internet connection by an alternative (back-up) connection (so called connection failover). This connection failover is launched automatically whenever failure of the primary connection is detected. When WinRoute finds out that the primary connection is recovered again, the secondary connection is disabled and the primary one is re-established automatically.

### Requirements

The computer hosting WinRoute must have two network interfaces for Internet connection: a leased line (Ethernet, WiFi) or a dial-up with persistent connection (CDMA, PPPoE) for primary connection and a leased line or a dial-up for secondary (failover) connection.

This connection type also requires one or more network cards for connection of individual segments of the LAN. Default gateway must NOT be set on any of these cards (cards for the LAN)!

In case of dial-ups, it is also necessary to define corresponding telephone connection in the operating system. It is not necessary that login data for telephone connections are saved in the system, this information can be specified directly in WinRoute.

Both the primary and the secondary link may be configured automatically by the DHCP protocol. In that case, WinRoute looks all required parameters up in the operating system.

It is recommended to check functionality of both the primary and the secondary link out before installing WinRoute:

- If these links are two dial-ups, dial one after the other and check the Internet connection.

- If the primary link is leased and the secondary a dial-up, test the primary link connection first and the secondary connection second. Dialing of the link opens (creates) a new default route via this link which allows us to test Internet connection on the secondary link.

- In case of two leased links, the simplest way is to disable one of the connections int he operating system and test the other (enabled) link. And, as implied, test the other in the same way when the first link is checked.

### Warning

Connection failover is relevant only if performed by a persistent connection (i.e. the primary connection uses a network card or a persistently connected dial-up). Failing that, the secondary connection would be activated upon each hang-up of the primary link automatically.

### Configuration with the wizard

On the second page of the Traffic Policy Wizard (see chapter 7.1 Network Rules Wizard), select Multiple Internet Links — Failover.

Figure 6.9. Traffic Policy Wizard — Internet connection failover

In the third step of the wizard, select a network interface for the primary connection (leased or persistent dial-up link) and for the secondary connection (leased or dial-up link). If login data for the selected telephone connections are not saved in the operating system, enter the valid username and password.

Figure 6.10. Traffic Policy Wizard — failover of a leased link by a dial-up

### Resulting interface configuration

When you finish set-up in Traffic Policy Wizard, the resulting configuration can be viewed under Configuration → Interfaces and edited if desirable.

Figure 6.11. Configuration of interfaces — Internet connection failover

The Internet interfaces group includes the Internet and the Dial-up link selected as primary and secondary (failover) on the third page of the wizard. The information provided in the Internet column states which link is used for primary and which one for secondary connection. The Status column informs of the link status (up/down) as well as of the fact whether the link is active (just being used as Internet connection at the moment) or not.

Other interfaces (including Dial-In) are considered as segments of the LAN and put in Trusted / Local interfaces.

The Internet interfaces group can include also other links. If these links are connected, standard routing with IP address translation (NAT) will be applied. Obviously, these links will not be backed up by any failover. Such configuration is not of any particular help, anyway. It is recommended to use the Internet interfaces for primary and secondary connection links only.

To change settings of primary and secondary connection, use corresponding options in the interface edit dialog (see chapter 5 Network interfaces) or use the context menu called up by right-clicking on the corresponding link. However, under any circumstances, always a single link can be set as primary connection and a single one as secondary.

### Probe hosts

Functionality of primary Internet connection is regularly tested by sending an ICMP request for a response (PING) to certain hosts or network interfaces. By default, the default gateway of the primary connection is used as the probe host. If the default gateway is not available, the Internet connection is not working (correctly).

If the primary default gateway cannot be used as the testing computer by any reason, it is possible to specify IP addresses of other (one or more) testing computers upon clicking on Advanced. If at least one of the tested devices is available, the primary connection is considered as functioning.

Figure 6.12. Internet connection failover — setting probe hosts

Note:

1. 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. This is one of the cases where the primary default gateway cannot be used as the testing computer.

2. 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.

3. ICMP queries sent to probe hosts cannot be blocked by the firewall's traffic rules.

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6.2 Connection with a single leased link — dial on demand | Contents | 6.4 Network Load Balancing