The link balancer spreads the traffic over several Internet links according to their weights, and switches over automatically when a link fails.
It covers both the traffic routed by Artica (gateway mode) and the traffic emitted by Artica itself (proxy, DNS, updates).
¶ How it works
- Each link is a network interface with its own gateway. Artica builds one routing table per link and spreads new connections over the links according to their weights; a connection always stays on the link it started on.
- Every 10 seconds, each link is checked by a ping through that link. A link that stops answering is removed from the balancing; it comes back when it answers again.
- The normal default route of the appliance stays in place underneath: if the link balancer is switched off, traffic follows it again.
- Firewall rules can force some traffic through a given link: action Send through a link.
¶ Enable the feature
The link balancer requires the firewall. In Your system › Features, install Link Balancer: the Link Balancer entry appears in the network menu.
¶ Configure the links
The page lists the interfaces that can be used as links:
Click an interface to set it up:
- Check: Ping (recommended) or Always up (no check).
- Address to ping through this link: a reliable address reachable through this link (a public DNS server, your provider's gateway).
- Weight: the share of new connections sent to this link. With weights 3 and 1, about three connections out of four use the first link.
Enable at least two links, then click enable at the top of the page. The Status column shows, for each link, whether it is up and used.
¶ Send traffic through a chosen link
Create a firewall rule with the action Send through a link and choose the link in the Link field. Typical use: send the backups through the second link, or the VoIP traffic through the most stable one.
¶ Good to know
- With fewer than two available links, the balancing is removed and the default route is used.
- IPv6 is not balanced.
- Traffic already marked by another Artica function (transparent proxy, mark rules) is not balanced.