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

You can configure Multi-Link with a Firewall Cluster consisting of two nodes by using two routers and two switches and physically connecting each node to each switch.

Figure: Cluster interfaces for Multi-Link

1
  Interface 1 on Node 1 is used as the CVI for Internet traffic that is routed through ISP A.
2
  Interface 2 on Node 1 is used as the CVI for Internet traffic that is routed through ISP B.
3
  Interface 1 on Node 2 is used as the CVI for Internet traffic that is routed through ISP A.
4
  Interface 2 on Node 2 is used as the CVI for Internet traffic that is routed through ISP B.

Both nodes have one physical interface for each CVI, so that both nodes are physically connected to both switches that are connected to the routers that lead to the Internet.

CAUTION:
We do not recommend configuring Multi-Link by connecting two CVIs to a single router, which in turn connects to both ISPs. It creates a single point of failure.