Servers can have redundant hard drives, power supplies, and so on. OpenBSD supports redundant network connections by combining multiple Ethernet links into a single virtual link, or trunk. You might also know of this as link aggregation, network adapter teaming, or bonding.
Cisco people know of trunks as Ethernet links that support multiple concurrent VLANs. Most vendors, including OpenBSD, don’t use the word trunk in that way. OpenBSD supports sending multiple VLANs over a single link outside the
To use multiple physical links as a single large link, you need a way to distribute traffic between the links. OpenBSD supports five different ways to distribute frames between trunk ...