関連ワード:  two types of data link layer    two types of networks at the data link layer    what are the two types of data link layer or sublayer    different types of data link layer    explain different types of data link layer protocols    two types of network layer firewalls    two types of network layer    list and describe the two types of networks at the data link layer    what is data link layer    what are the two sublayers of the data link layer