Blocked ports between TUnet and Internet

*) Incoming mails are routed through the mailbastion server.
(Third party domains with TU Wien mail servers can also be handled by mailbastion).
Transport Port Protocol Description Direction
ICMP - ping Echo request from outside
IP protocol 41 - IP in IP Tunneling IPv6-Tunneling method such as 6to4 and ISATAP both
UDP,TCP 7 echo Echo Service from outside
UDP,TCP 9 discard Discard Service from outside
TCP 25 SMTP Simple Mail Transfer Protocol - E-Mail-Transport from outside *)
UDP,TCP 53 DNS Domain Name System - Nameservice from outside
UDP 67 BOOTPS Boot Strap Protocol Server, DHCP both
UDP 68 BOOTPC Boot Strap Protocol Client, DHCP both
UDP 69 TFTP Trivial Filetransfer Protocol (without password) from outside
UDP,TCP 111 ONC RPC (Sun RPC) Portmapper (a.o. for NFS) both
UDP 123 NTP Network Time Protocol - Time Services from outside
UDP,TCP 135 msrpc Microsoft Remote Procedure Call both
UDP,TCP 136 Profile Name Service no longer a legitimate application both
UDP,TCP 137-139 NETBIOS via TCP SMB (Server Message Block) - File and printer service both
UDP,TCP 161-162 SNMP Net-Management both
UDP,TCP 177 XDMCP X Display Manager Control Protocol both
UDP,TCP 445 Microsoft-DS Microsoft Directory Service (SMB over IP, CIFS) - File and printer service both
TCP 512 rexec R-Commands (Remote Exec) from outside
TCP 513 rlogin R-Command (Remote Login) from outside
UDP 514 syslog System Logging Service from outside
TCP 514 rsh, rcp, rdump, rrestore, rdist R-Commands (Remote Shell, Copy, Dump, Distribution) from outside
TCP 515 lpd Line Printer Daemon - Printer Service from outside
TCP 540 UUCP Unix to Unix Copy Protocol - u.a. E-Mail-Transport from outside
UDP,TCP 623 IPMI IPMI Management both
TCP 1080 SOCKS Application proxy from outside
UDP 1434 SSRS SQL Server Resolution Service both
UDP,TCP 1900 SSDP Simple Service Discovery Protocol from outside
UDP,TCP 2049 NFS Network Filesystem (other ports possible) - File service both
TCP 3128 Squid Web-Proxy from outside
UDP 3544 Teredo Encapsulation of IPv6 data packets in IPv4 UDP data packets both
UDP,TCP 4045 lockd NFS Lock Manager - File service both
UDP,TCP 5000 UPnP Universal Plug and Play Service from outside
UDP 5353 mDNS Apple Bonjour Service from outside
TCP 6000-6063 X11 X Window Display Server (X-Terminal) both
UDP,TCP 9100 PDL Page Description Language - Printer service such as JetDirect both

Handling of external access to TUnet (VPN, lecture halls, WLAN):

  • Outgoing traffic as shown in the table above; Port 25/TCP (for sending mail) to external mail servers is also blocked for WLAN and lecture halls.
  • Traffic coming from the Internet is blocked. SSH is excluded from student workplaces at the University of Vienna due to inter-university studies.

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