Customer conversations

Working in IT and dealing with problems or setting up new systems involves talking to customers.

Occasionally these are amusing enough to repeat. Here is one.

I was setting up a new server with file, print, and email. As it happens I was using Novell OES, and GroupWise 7 for Linux, which comes with clients for Windows, Apple Mac, and Linux as well as a web interface.

When setting up email you have a bunch of people who need mail boxes and they have a standard format of email like logonname@somedomain.co.uk or firstname.lastname@ etc....

You also need some alias or group email addresses like sales@ and perhaps the odd one or two for people who have left who's mail you may want to redirect to some one else.

Anyway, so there I am, installing this system, and ask "what about email aliases?"

I get a nine yard long list, which includes many different ways of spelling peoples names people who left ages ago etc.

So I say:

"Why not tell them to f*ck off and learn how to spell?"

Customer
"That does not fit in with our customer focused strategy"

Ah well....

More on email miss spellings another day.

Streuth!

25,648 Spam mails bounced in one day just using block lists that I implemented yesterday on one server.

Wow that is a lot.

Mind you some of those may be spammers trying again.

Gotcha!

Got the Spammers by using RBLs.

I put this in my postfix servers main.cf:

maps_rbl_domains = relays.ordb.org,
bl.spamcop.net

smtpd_recipient_restrictions =
permit_mynetworks,
reject_unauth_destination,
reject_maps_rbl,
permit

And now I get to see lots of open relays, probably home PC's taken over as zombies being rejected!

Good.

By the way, Postfix is brilliant, Well done Wietse Venema!


Update. So far on one server alone, 1200 spam emails bounced in 1 1/2 hours!

I'll have to roll it out elswhere.

Update at 17:30

Stopped 3258 spams that way. Bog off spammers!

Arghhh... Spammers

I hate spammers. Gits.

Just who do these people think is going to get an email addressed to akshdsbfkjsb@somedomain.com?

Why bother? They are just clogging up the internet with rubbish. They are the internets fly tippers.

Gits!

Linux tip of the day

I am no Linux Nerd god, but I do a bit and come across a really useful tit bit.

Here is one.

Lots of things on Linux (or UNIX) get logged in log files. If something is going wrong it can be useful to look at the log files, that's what they are for. The problem with these log files is they can be big and you may be looking for a needle in a haystack.

However there are tools to help. Here are the ones I use most.

Tail. If you tail a file it shows you the end of the file. Like for example:

tail /var/log/mail

will show the end of the mail log file (assuming that /var/log/mail is your mail log file).

tail -f /var/log/mail

will show you the end of the log file, but will also show you any new bits as they are added. Very handy. So you tail -f the log file, then replicate the fault and the answer pops up on the screen.

Some times though, tailing a log file is hard work as on a busy mail server stuff is flying up the screen at a rate of notts.

That's where grep comes in. You use grep to show you a line in a file which contains a given expression. For example:

grep me@somedomain.com /var/log/mail

will give you every line of the log file that has me@somedomain.com in it. Fantastic.

One of the great things though about the Linux command line is that you can get one command line program to pass its output to another to do something else with it to produce a more refined out put. So how do we find something useful that is about to happen in a log file that is growing quickly?

Here's how:

tail -f /var/log/mail | grep me@somedomain.com

That will show any new lines in the log file that contains the email address.

Of course you need not be looking at a mail log file or for an email address. If you use fetchmail and only want to see what fetchmail is doing rather than the rest of the mail system you would type:

tail -f /var/log/mail | grep fetchmail

(fetchmail normally puts "fetchmail" in any entries it makes in a log file.)

grep can also return lines before and after the line you were looking for. Use -A num for after occurrence and -B num for before.

You can also man grep to get the full manual page, or for an easier on the eye read you can also type man grep into google and read man pages on line.

The "|" is the symbol for pipe. On a UK keyboard you will find it on the bottom left hand side, and will need to press shift to get to it. What it means is pipe the output of this program to that over there. Works very well.

Geeky things I do at work

Well, I work in IT, so there are many things I do with computers that other people just don't get. Frequently it seems I am almost speaking another language.

Just recently I have bee setting up a server running Novell OES. Oh the joy that some of that has been.

I also do a lot of Linux. Personally my favourite flavour of Linux is Archlinux. I just like the way it is laid out.

More later....