How to determine source of mysterious server name on my network

Over the last few days I have noticed a mysterious (unknown to me) server hostname that shows up on both Ubuntu's Nautilus Network section as well as Windows File Manager network group. The hostname does not show in the list of clients on my router. If I double click the hostname icon to try to connect to it I get a connection refused error. The hostname's appearance is random.I have non-factory admin and wireless passwords set on my router as well as MAC filtering. Router firewall is on and no unneeded service ports are opened (NFS, etc.).H...Read more

network security - IDS Evasion Techniques and tools over several protocols

I need some IDS evasion attacks to test an IDS product.All I can find is an old paper titled "Insertion, Evasion and Denial Of Service: Eluding NIDS" by Thomas.H.Ptacek and Tim Newsham.It is kind of too old,and there must be some new ways through those years.Also there maybe some other tools like fragroute.I need to find them.So give me some clue where to find it. Thanks.And here is what is evasion attack from the paper I mentioned:An end-system can accept a packet that an IDS rejects. An IDS that mistakenly rejects such a packet misses its con...Read more

network security - Best way to prevent denial of service attacks on a website

I have a web app and I would like to prevent DOS attacks by blocking an IP address if it make many request in a short period of time.For example, if the same IP address makes 100 request in a second, I can assume that it's some kind of attack and I would like to block this IP.However, making this check in the application layer seems too expensive - what is the optimal way to make this check?Should I make this kind of check at my:firewallrouterapache configsomeplace else entirely ......Read more