Andrey Mikhalchuk’s Blog

I started republishing posts from my old website about immigration to Australia. First few posts are available here, more are coming later. All posts are in Russian. All posts are not published on the first page.

For debugging purposes I frequently need to quickly convert ip addresses from one representation to another. Here is quick and dirty (I’ll cleanup the interface when get some free time) converter that does the job.
If you don’t see the form below because of some reason please proceed to this page.
The following formats are supported:

• integer
• unsigned integer
• dot notation
• hex number
• binary number
• octal number
• natural netmask

Please specify one of the following

When I used NFS first time 15 years ago on Sun it seemed to me the top of progress. And it really was at that time. So dealing mostly with samba during last few years I forgot how actually NFS works until a few days ago when I issued standard “mount server:/directory /mnt/subdir” and tried to compile a project. The performance was HORRIBLE. So I spent some time investigating how to improve NFS performance and found this solution:

Recently I’ve got $10 charge from company called “Reservation Rewards” …
I’ve seen this company before in one of those “Use your chance to get $20″ with really long explanation that hides the fact you have to subscribe to “Reservation rewards” for $12/month in order to get those $20. But I was very patient first time I saw this ad, I noticed this hidden subscription, noticed checkbox that was prechecked for me and since then carefully hidden subscriptions like this. So here is the story about Reservation Rewards subscription with happy end.

I recently uploaded a sitemap for a new website to google and It looks like google webmaster tools do not accept sitemap containing just single url. The error it reports is “Missing XML tag”.

When you need to implement a DNS master/slave relationship, you obviously can go ahead and edit named config files, but when you do next change to DNS configuration using Plesk most your changes will be lost. From the other side Plesk doesn’t provide slave server configuration at all! Here is the solution that works for me on Plesk 8.2. Versions 8.3 and above support the master/slave DNS configuration via web interface.

Sometimes, for security reasons, it is useful to disable pop3 protocol on a server, leaving users with necessity of using secure pop3 protocol (i.e. in outlook they will have to check “Use SSL checkbox”, otherwise mail just won’t work). The civilized method is of course just ask people politely to make changes to their settings, but frequently people just don’t have time to do so. This tiny hack will force them to do so, otherwise their mail just won’t come.

When your mail is not working it is important to know exactly what part is broken (so you know if you should go blame sysadmin or just check your mail client settings). Let’s simulate basic POP3 client using regular telnet (enter commands without quotes) in order to check if the POP3 is doing fine:

“553 sorry, that domain isn’t in my list of allowed rcpthosts; no valid cert for gatewaying”
There could be many things leading to the problem. One of them is client inability to authorize to SMTP server. Here’s a quick explanation of what happens and how the problem could be solved.

Despite the process of obtaining an SSL certificate for your website is not very difficult it may take you plenty of time, because the price of mistake could be rather high. I’d say you can loose hundreds of dollars if you buy wrong type of certificate or get it from wrong place. Here’s a quick overview of the process that will make your SSL cert shopping experience more enjoyable.

Howdy! This blog is about various technical stuff like coputers, gadgets, photos etc etc. Enjoy