Switch and switch system

A switch system, comprising:

• a plurality of switches,
• wherein the plurality of switches are classified to a plurality of domains, each of which includes plural switches to be virtually integrated, and
• at least one of the plurality of switches comprises:
• a plurality of ports that comprise a first port to be connected to another switch included in a first domain of the plurality of domains, and a second port that is other than the first port;
• a first processing unit configured to obtain data of a switch included in the first domain through the first port;
• and
• a second processing unit configured to obtain data of switches included in a second domain that is adjacent to the first domain through the second port and obtain data of switches included in the second domain from the another switch included in the first domain to identify, from among the plurality of ports, plural ports that are connected to the second domain, perform a setting for the identified plural ports, and perform a first processing to make the plurality of domains that include the first and second domains a tree structure.