deviceControlTcpPort 1.3.6.1.4.1.8691.2.8.1.4.1.2.1.1.1.11

The 'TCP port' is the TCP port that the NPort 6000 series device server uses to listen to connections, and that other devices must use to contact the NPort 6000 series device server. This setting is used in RFC2217 mode.