Contact Information
- Name: CAEN Staff
- Email: caen@umich.edu
- Phone: (734) 764-CAEN
Releases Quick Access
Selected ports to be blocked
On Monday, May 15, CAEN will begin blocking off-campus access to a number of network service ports. Blocking these ports will reduce common network scans and attacks directed at Windows-based computers and improve overall network security. ITCS already blocks these network service ports for the rest of campus, and most ISPs also block them. The most visible impact of these blocks will be the inability to login to or access Active Directory, Exchange, or Windows file shares from off-campus. On-campus access to these services will not be affected. A number of alternative methods exist that will allow you to get access to network resources that may natively use these ports to communicate. In particular:
- The campus Virtual Private Network (VPN) service will provide a way to get access to all network service ports blocked by this change. For more details see www.itcom.itcs.umich.edu/vpn.
- Apple users, in addition to the campus VPN, can use CAEN's native Mac VPN. For more details see www.engin.umich.edu/caen/network/wireless/docs/macosvpn.
- Secure FTP provides another mechanism for remote file access to files including CAEN Windows home directories. For more information on using secure FTP in the CAEN environment as well as other general off-campus file access methods, see www.engin.umich.edu/caen/faqs/Accounts/NAS/. For information on obtaining the secure FTP software, see www.itcs.umich.edu/itcsdocs/s4299.
The ports that will be blocked are the main ports used by Microsoft Windows for File Sharing, Exchange, SQL, and directory/domain services. The specific list of blocked network service ports are TCP/UDP 135, 137, 138, 139, 445, 1433, 1434. A more detailed list of network service port assignments used by Microsoft Windows can be found at the Microsoft web site.
See CAEN's FAQs for more specific information on Windows port blocking at the CoE. If you have any questions regarding how this change will impact your off-campus access to on-campus computing resources, or on using the VPN service, contact the CAEN Hotline (caen@umich.edu; 734-764-CAEN).
