On Wed, Feb 01, 2017 at 11:55:46AM -0600, Dennis Wicks wrote: > I find myself with several unused NICs (network interface cards) and some > empty ports on my switches. > > Would it be beneficial to have more than one network connection on a system? > > If so, what would I do with it, and how would I set it up? Pointers to > tutorials and how-to's would be nice!
Case 1: A system becomes a router. Each NIC attaches to a different IP network. Turn on IP Forwarding. Now it's a router. Run iptables, and it's a firewall, too. Case 2: a system gains redundancy and capacity. Each NIC attaches to the same switch. The switch has to be configurable to do Link Aggregation Protocol -- not all can. You configure the system NICs to become a bond device, using 802.3ad mode. Now traffic can flow through all the bonded NICs and is resilient if one of the links dies. Case 3: direct connection to another system. If you have, for example, a machine which offers a lot of storage and a machine which uses a lot of storage, you can connect them directly and gain speed and security, possibly at the cost of redundancy. -dsr-