I recently discovered a wonderful DNSBL service reporting you where public Internet IPs are from.
The service is countries.nerd.dk: http://countries.nerd.dk/more.html
You can for example block any mail at your mailserver coming from china or russia, simply integrating this DNSBL with your MTA.
You can even get the country of your IP with dig!
Warning: You need to swap IP octets. If for example the IP to check is 18.104.22.168, you have to call 22.214.171.124.zz.countries.nerd.dk.
root@nbvirtdns1:/# dig TXT 126.96.36.199.zz.countries.nerd.dk
188.8.131.52.zz.countries.nerd.dk. 1047 IN TXT “it”
I would not recommend you to host sites that way, you have to be sure that your ISP give you public IP(s) and setup your router to port forward ports 80, 443, 53, and so on.
There are other problems too:
1) if you want to host more than one site with SSL you must have one public IP for each SSL site or use different SSL ports for each site, because name virtualhosting with SSL is not possible;
2) dsl lines are not designed to be stable. The connection can go down and make your site not visible. This is a major problem if you make the mistake to have your own DNS server on it!! The ISP assigned public IP address can change more than one time a day and you have to sync the DNS zone each time.
3) dsl ips are putted into DNS based blacklists zones. You may not be reached from various HTTP proxy servers around the world. For the same reason you cannot send mails, for example originated from your sites.
4) adsl lines are asymmetric (unbalanced for download). You have few kbytes per second in upload, that is just what you need to publish web sites, so this can be a problem when you have just more than 3 users.
5) you probably have problems with High-Availability and Load-Balancing on domestic hardware and you may have blackouts.
6) DNS subsystem may need primary and secondary DNS servers.
The best way (imho) is to use services like slicehost where you have a HA virtual server slice running linux, public IP addresses, free primary and secondary DNS hosting service, large public bandwidth, disk space… and not last your own root password that you can use to have maintenance on your own server for your own.
Se quello che hai sempre cercato e’ avere il tuo personalissimo server linux up and running 24 ore su 24, SliceHost e’ l’opzione giusta per te.
Questa meravigliosa azienda americana (in Italia purtroppo certe cose ce le sogniamo alla grande!) ha sviluppato un sistema automatico con interfaccia web in grado di fornirti in tempo reale per pochi dollari al mese una tua personalissima macchina virtuale con cui potrai realizzare e gestire il tuo server linux in tutta tranquillita’.
Banda e connettivita’ internazionale a internet non sono un problema e potrai scegliere tra vari tagli di offerte pronte per te.
Se sei interessato, dai un’occhiata al sito https://manage.slicehost.com/customers/new?referrer=af57db3020e04bb27352e271753a7a18 e affiliati anche tu.
Avrai la possibilita’ di scegliere la distribuzione linux che piu’ ti aggrada e il tuo server linux personale sara’ in piedi in pochi secondi.
Noi di TuxWeb lo stiamo utilizzando con successo per gestire i siti internet di alcuni nostri clienti.
Ciao, Dino – http://www.tuxweb.it/
I’m now talking about a simple GPLv2, C written, small program that work as a very fast clamdscan antivirus frontend.
Scandalo can take a mail on standard input and parse it from viruses, piping it to clamdscan.
It then get the virus status from clamdscan and put a mail header called “X-Virus-Ret” returning the virus scanner status.
It also put a mail header called “X-Virus-stream” returning the first virus name found (if any).
You can then setup a rule on your (say, maildrop) mail filter to pipe the incoming mail to scandalo, and another rule to check the return scanned mail header for viruses.
If a virus was found, you can drop the mail, or put it into a .Virus maildir.
If you have any question, I’m the developer of scandalo.
Scandalo – http://www.tuxweb.it/?section=progetti/scandalo&
Write me a note at firstname.lastname@example.org.