Yes thinkpads and Ethernet cable and routers and web servers (IIS and Apache Tomcat) are part of the Operational local network (OpsLan) onboard the ISS - they are used primarily for astronaut (crew) mission planning, procedures and electronic communition - systems that are deemed not to be flight critical and are not directly used in command and control of the spacecraft (think email, documents and other messaging and notification systems)

Source: I was a ISS Flight Controller for 6 years and helped write the software for local intranet websites hosted onboard the ISS for the crew