Introduction

The chapter "Remote Access" will show you possible solutions to remotely access a managed client or your data inside the D-ITET networks from the selfmanaged client network or from devices outside the ETH network. It will cover the following topics:

• mailbox access
• remote terminal session
• remote desktop session
• file transfer
• network file system access

"Remote Access" solutions depend on the available (firewall enabled) protocols between the remote access client and the target network. With a view on the firewall, the networks relevant for D-ITET are segmented into 5 logical virtual private zones (VPZ):

• itet-isg (ISG managed servers and clients)

• itet-staff (Selfmanaged clients; most often these are selfmanaged laptops)

• itet-iot (Internet of things; small unmanaged devices, often lacking a possibility to configure them in a secure way)

• VPN zones (Public VPN zones; you will be assigned to this zone by default when you connect to the ETH network using the VPN client. An exception would be if a realm to enter a specific private VPZ zone is configured in the VPN client. The latter is only enabled in exceptional cases; contact ISG.EE for details.)

• Internet (all networks outside ETH intranet)

An ITET zone (VPZ) consists of multiple IP subnets. Traffic between subnets associated to the same VPZ does never pass the zone firewall and thus there are no restrictions (no IP's or ports blocked).

Here is a table with the relevant protocols for remote access:

The following table shows the available protocols depending on the source and target network:

*1) NFS access from unmanaged clients is not allowed for security reasons.
*2) These protocols are only enabled for the servers involved in the D-ITET mail system.

From the zones itet-isg and itet-staff to the internet the ip transport protocols udp/tcp are generally enabled. Every machine inside can initiate a connection to an arbitrary server port in the internet.

Mailbox Access

Web Access (Roundcube)

You can access your inbox and your mail folders with a web browser on any client with internet connectivity. Our web server with the Roundcube software can be reached under https://email.ee.ethz.ch .

IMAP/ SMTP Access

You can also access your mail with any IMAP/ SMTP based mail client software ( Thunderbird, Outlook, Smartphone Mail Programs, Windows 10 Mail, ......) over the internet. IMAP/ SMTP access to our mail servers is enabled for the internet. Detailed information is available in this Wiki under https://computing.ee.ethz.ch/Email .

SSH - remote terminal session

In the Unix/ Linux world a remote terminal is still widely used. The old telnet terminal is now replaced by the encrypted shell "ssh" which is secure enough to be enabled for the internet. You will need an ssh client. Under Linux and Macintosh OSX, the program is itself called ssh and is usually available in the basic installation of the operating system. Unter MS Windows, use a 3rd party manufacturer program like XWin32, PuTTY (http://www.chiark.greenend.org.uk/~sgtatham/putty) or the Cygwin SSH client (these have to be installed on the operating system separately).

Establishing a remote terminal session

• On an ETH-internal client you can simply enter

  ssh <account>@<targethostname>.ee.ethz.ch

  After a successful login, a remote terminal session is established on the selected target host. If you omit <account>@ in the ssh commandline, your shell's current login username is used.

• To connect to an ssh service from an ETH-external client, one must either install and activate the VPN client software on that computer and then proceed in a way as if the client were an ETH-internal computer (see above).

• Alternatively, for ETH-external clients, one may establish a "direct" connection (without VPN client) to the target host via our login server login.ee.ethz.ch. For the latter, use the following commandline (example for the Linux built-in ssh application):

  ssh -o ProxyJump=<account>@login.ee.ethz.ch <account>@<targethostname>.ee.ethz.ch

• For a key-based ssh login see https://computing.ee.ethz.ch/FAQ/SSHkeys .
  
  

SSH details

The ssh protocol has some integrated features like

• X11 forwarding (run a Linux GUI application remotely and display it's window on the local computer)
• encrypted file transfer, encrypted remote shell sessions
• ssh tunnelling (purpose is most often to bypass firewall restrictions)

With these features ssh also offers solutions to additional tasks which are covered in the following chapters.

As a default entry point you can use the host login.ee.ethz.ch. Use this host only as a starting point, but do not execute processes that will consume a lot of CPU resources (e.g. do not use matlab on this machine!).

If you are not sure if you connect to the right server you can check it here: https://computing.ee.ethz.ch/SshFingerprints. We created a website where you can check if the PC you are connecting to is the same key as the PC we manage.

Remote Desktop Session

Windows RDP

The Microsoft Remote Desktop Protocol is the remote desktop solution in the windows world. An RDP-server component is integrated in all Microsoft operating systems and the protocol is widely used for terminal server access. An RDP client software (rdesktop, xfreerdp,..) is also available for linux, so it's no problem to get a windows remote desktop on a linux client. Here are the sample commands for rdesktop and xfreerdp:

> rdesktop -u d\\pmuster -k de-ch -g 1280x1024 vega7.ee.ethz.ch
> xfreerdp [-sec-nla] [/cert-ignore] /size:1920x1100 /u:pmuster /d:d /vega7.ee.ethz.ch

[ ] are optional parameters and their need depends on the configuration settings of the terminal server.

On windows machines you can start the RDP client with mstsc.exe .

VNC

VNC is the preferred solution for remote desktop sessions on linux machines. A detailed description of the usage of VNC is in the FAQ (https://computing.ee.ethz.ch/FAQ/VNCUsage).

File Transfer

Http download

The http download is a simple solution to transfer a data file to an external user. On the client side no additional software is needed, a web browser is sufficient.

Here are the sample commands to provide a data file for download with a required authorization in your personal web page:

> mkdir /home/pmuster/public_html/transfer
> cp /scratch/pmuster/datafile /home/pmuster/public_html/transfer/
> htpasswd -c /home/pmuster/public_html/.htpasswd download

Create a file .htacces in the download folder /home/pmuster/public_html/transfer with content:

AuthUserFile "/home/pmuster/public_html/.htpasswd"
AuthName "Downloads"
AuthType Basic
Require user download

Under the address http://people.ee.ethz.ch/~pmuster/transfer the file can now be downloaded with user download and the password set with the htpasswd command.

Linux scp

Between two Unix/Linux machines you can transfer a file with the ssh-integrated secure file copy (SFTP). The command is:

ubuntu@home> scp <path-to-datafile> <user>@<dns hostname>:<path-to-target directory>

With the command

ubuntu@home> scp document.pdf pmuster@login.ee.ethz.ch:Documents/

the file document.pdf on your linux machine is copied in the Documents subdirectory in your home at D-ITET.

Windows WinSCP/Filezilla

Windows has no ssh integrated, so you must use an additional software. The popular programs WinSCP (https://winscp.net) and Filezilla (https://filezilla-project.org) are the preferred choice. Filezilla is also available for the linux platform and is already installed on our managed linux clients.

ID polybox - Own Cloud Storage

ID provides 50 GB storage to every ETH member (https://www1.ethz.ch/id/services/list/polybox/index_EN). The polybox client software is available for different plattforms and synchronizes a local storage on the client with the owncloud server storage. If the client software is installed on two machines you can therefore transfer data between the two machines with the polybox client.

Cifex

ID offers also a service for the exchange of big sized files which can not be send by mail named Cifex (https://cifex.ethz.ch/). The mail size limit depends on the provider but normally files greater than 50-100 Mbyte can not be send by mail. It's a good solution for sporadic transfers of big sized data files to a site where no n-ethz account can be used.

Network File System Access

NFS access

Because NFS is not enabled between the internal networks nor to the internet it has no significance in remote access solutions. NFS is only used by ISG managed linux clients to access user and project homes on servers and dedicated storage systems of ID and ITET by automount tables.

SMB/CIFS access

This Microsoft network file sharing protocol has a user based authentication and therefore has a great significance for accessing data resources not only on windows file servers. Linux/Unix servers are also providing SMB/CIFS access with use of the samba software suite, an emulation of the windows file sharing protocol for Linux/Unix file servers.

More information how to access your data you find under:

• https://computing.ee.ethz.ch/Workstations/FindYourData

• https://computing.ee.ethz.ch/Services/FileAccess