The hashing algorithm takes the destination MAC address (or another value, as you'll see later), and hashes that value to a number in the range of 0-7. The same range is used regardless of how many links are actually in the EtherChannel. Each physical link is assigned one or more of these eight values, depending on how many links are in the EtherChannel. Figure 7-3 shows how packets are distributed according to this method. Notice that the distribution is not always even. This is important to understand because link usage statistics-especially graphs-will bear it out. Number of physical links Figure 7-3. EtherChannel physical link balancing On an EtherChannel with eight physical links, each of the links is assigned a single value. On an EtherChannel with six links, two of the links are assigned two values, and the remaining four links are each assigned one value. This means that two of the links (assuming a theoretical perfect distribution) will receive twice as much traffic as the other four. Having an EtherChannel thus does not imply that all links are used equally. Indeed, it should be obvious looking at Figure 7-3 that the only possible way to distribute traffic equally across all links in an EtherChannel (again, assuming perfect distribution) is to design one with eight, four, or two physical links. Regard- less of the information used to determine the link, the method will still hash the value to a value of 0-7, which will be used to assign a link according to this table. Load Balancing The method the switch uses to determine which path to assign can be changed. The default behavior is that the destination MAC address is used. However, depending on the version of the software and hardware in use, the options may include: The source MAC address The destination MAC address The source and destination MAC addresses The source IP address The destination IP address The source and destination IP addresses The source port The destination port The source and destination ports The reasons for changing the default beh