Tag Archives: firewall

Sysadmin: block these pesky recursive DNS queries with iptables rate limiting rules

dns-reflectIf you are managing Linux server you have probably heard about recent DNS amplification attacks that were using misconfigured DNS servers.
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sysadmin: Brute Force Detection – first line of defense

Most of the hosting servers nowadays are plagued by brute force attacks – too many computers running some or other botnet, too many “no brainer” scan tools are available for the interested.
There are always somebody who doesn’t bother to select good password to secure his account on the server and that could potentially bring a lot of problems not only to him but to the whole hosting company as well – imagine brute-forced password used for SMTP AUTH to send massive amounts of SPAM from the compromised server?
Now there is lot of countermeasures invented for that and here I will explain which one I prefer and why.
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VPN from Vmware Guest OS on windows 7

I have couple of Vmware VMs that I am carrying with me from computer to computer and using on regular basis. One of these VMs is used for corporate PPTP VPN.
After my last transition to Windows 7 this VPN stopped working. It took me some time to find the solution to this problem. Read more »

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