The Informatikdienste are upgrading the routers in our HIT/D/13 server room causing a downtime of the network of about 1 hour on Thursday morning, 15th September, between 05:30 and 07:30. Please note that various services will not be available during that time.

After several years it was time to update the SSH host keys of our managed Linux machines. Therefore, if you reconnect with SSH, you might get a warning similar to this one:

ssh login.phys.ethz.ch
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
36:04:d8:3d:89:a2:76:19:ef:b6:f0:0a:f2:5c:81:a3.
Please contact your system administrator.
Add correct host key in ~/.ssh/known_hosts to get rid of this message.
Offending key in ~/.ssh/known_hosts:1
RSA host key for login.phys.ethz.ch has changed and you have requested strict checking.
Host key verification failed.


This is because your computer has memorized the previous host key and is bailing because the current one is different. This mechanism is designed to prevent users from man-in-the-middle attacks. In our case it can be treated as a mere notification that the SSH key has changed.

In order to get rid of this warning, you simply need to delete the old key from your ~/.ssh/known_hosts file. This can be done either by deleting the entry manually or with the following command

ssh-keygen -R login.phys.ethz.ch

for the machine you try to ssh into.

On the next SSH connection you will be prompted to accept the new key. Power users may also download the full list of SSH keys of all our managed Linux computers.

Apart from the file-, mail- and web servers exists another crucial element of our core server infrastructure, namely the servers managing the account information and logins (LDAP). With a current uptime of a remarkable 550 days, it is time for an upgrade of the operating system and high-availability cluster software. For this reason we schedule a downtime on Wednesday 18th July between 07:00 and 08:00.

Most services will be affected and unavailable during that time, as they require an authentication with your D-Phys account (email, file server, print server, managed workstations). Note that, even though you will not be able to check your emails or send new ones, all incoming mails will be received and safely delivered to your inbox afterwards.

If everything goes smoothly, the actual downtime should be considerably less than the scheduled hour.

We developed a real-time monitoring of the number of pages printed in physics department. We keep track of the printed pages on each printer and the total for our two servers (cups and winprinter). The results are plotted on our printer homepage printer.ethz.ch. Clicking on the upper graph shows you more details, as well as the statistics over the last 30days. Moreover you can click on the little "Stats" icon next to each printer, to see its individual statistics.

These statistics not only help us to monitor and debug our printers, but should also make everyone aware of the large amount of pages printed in D-Phys, namely that more than 5000 pages are printed every single workday.

Please be eco-friendly and print only when you need to.