# Using Multi-Link with a Single Firewall for outbound traffic management

You can configure Multi-Link with Single Firewalls where each interface is connected to a router from a different ISP.

Figure: Single Firewall interfaces with Multi-Link

CAUTION:
We do not recommend defining two or more IP addresses for a single physical interface. If two IP addresses are defined, the router behind the interface forwards the traffic to the different ISPs. This creates an additional single point of failure at the intermediate router, and the associated cabling and network cards.

1
  interface 1 is used as the network interface for Internet traffic that is routed through ISP A.
2
  Interface 2 is used as the network interface for Internet traffic that is routed through ISP B.