Information processing system and control method for information processing system

An information processing system, comprising:

• a plurality of switches, each of which is classified to any one of a plurality of domains that are connected in a form of a tree, wherein a plurality of physical links between two domains among the plurality of domains are set as one logical link;
• an information processing apparatus connected to one of the plurality of switches;
• and
• a management apparatus connected to one of the plurality of switches, which manages assignment of channel IDs, wherein
• the information processing apparatus comprises:
• a first memory;
• and
• a first processor coupled to the first memory and configured to transmit an assignment request whose destination is the management apparatus,
• the assignment request is relayed from the information processing apparatus to the management apparatus via a first switch among the plurality of switches,
• the first processor receives a response for the assignment request from the management apparatus,
• the response for the assignment request includes a channel ID,
• the first switch comprises:
• a second memory;
• and
• a second processor coupled to the second memory and configured to:
• upon receiving the response for the information processing apparatus from the management apparatus, makes first settings for relaying a packet whose destination is the information processing apparatus, based on the channel ID included in the response and an identifier of a first logical link that includes a first plurality of physical links and through which the assignment request was received, wherein the first switch and at least one second switch belong to a first domain among the plurality of domains, the first domain being connected to a second domain among the plurality of domains through the first logical link, the second domain including one or more switches and the second domain being a lower-layer domain than the first domain in the tree;
• and
• transmits, to the at least one second switch, a request to make second settings for relaying the packet whose destination is the information processing apparatus, wherein the request includes the identifier of the first logical link and the channel ID included in the response.