FAQ - Frequently Asked Questions/Netiquette

Verze z 4. 2. 2007, 12:46

What should I do, when I receive spam or hoax or when someone tryed to crack my computer?

If you're convinced that it is a real threat (some security programs display attempt at hack even in case of ordinary ping) you can do the following things: post a message to discussion group localnews.sh.cvut.cz to group info.sh-net, or even better send an email to klub@sh.cvut.cz (it is read by all admins in Strahov). Portscan or attempt to connect with your computer is not a reason to write at info.sh-net. Best is if you first try to discuss it with somebody into IT. In most cases the attack is done by a virus not a person. If it is a member of student club, you can find and contact him/her by mail (find out in DUSPS database).

How should posts to newsgroups and emails look like?

Mail should be starting with a salutation and end with a signature. If you are unsure recipient is able to view encoding, don't use that (in case of other than English alphabet). If you want to insert a non-english text into the message, make sure that it has the same encoding. If you are writing a reply, split the text of original letter at least with one empty line.

Why shouldn't I send emails with size exceeding 50 kB?

You send a mail with size exceeding 1 MB. Recipient's mail server can be down for a while or could deny receiving mail. In this case the mail is returned and waits on [#zkratky-smtp SMTP] server. After some time it sends your mail once more. Assume that mail returns again, so sending server tries another time to deliver this large message. Even we consider successful receiving by recepients's mail server, it can last few days until he/she reads his/her mail. All this time oversized mail consumes valuable space on some of the servers, that could collapse when it runs out of free space. Moreover when sending or receiving so large message, the server is overloaded (for a few minutes or so) and requests of other users are delayed. For transferring larger amount of data the [#ftp FTP] (File Transfer Protocol) or [#http HTTP] (HyperText Transfer Protocol) is sufficient. For these purposes you can use your webpage on your block's server.

Why shouln't I post messages exceeding 50 kB?

E.g. you attach an image to your post, that has 500 kilobytes. Your client at first codes the message according to standard MIME. This coding enlarges the file by 30 percent on average (700 kB) in order to distinguish between control sequences of news protocol and the data file's content. The post is saved on newsserver up to 90 days and during the whole period consumes valuable disk space. Moreover users that use text-only clients, cannot view your attachment - they see only a bunch of characters of the encoded image. If you want to present a file to readers of localnews, just save your file to an [#ftp ftp] or http server and include the [#zkratky-url URL] in your message. For these purpose it is the best to use personal webpage at your block's server.