When the trunk is created it will in turn be assigned to one or more VLANs just like an interface.
How Trunks Work You are probably thinking; how do the devices ensure that frames are never sent out of order or even duplicated? The BIG-IP systems solves this by using what is known as Frame Distribution Hash which is used to determine which interface it should use to forward traffic. The Frame Distribution Hash creates a hash value based upon different values such as MAC or IP address. When the hash value has been calculated, it will send each frame matching the hash value over the same member link. You can base the hash on the following: ▪ ▪ ▪
Source/Destination MAC address - The BIG-IP system bases the hash on both source and destination MAC address. Destination MAC address - The BIG-IP system bases the hash on only the destination MAC address. Source/Destination IP address - The BIG-IP system bases the hash on both source and destination IP address.
Link Aggregation Control Protocol (LACP) We will not cover any in-depth detail of this protocol as the knowledge of how this protocol works are already expected and covered in the F5 ADF 101 Study Guide. However, when creating a trunk, you will have the option of adding this feature to the trunk. As you should already be aware of, LACP is an IEEE standard protocol that detects error conditions on member links and can redistribute traffic to other member links in order to prevent loss of traffic when a link fails. The behavior of LACP is customisable where you for instance can choose how LACP should communicate its control messages from the BIG-IP system to the peer system.
505 505