Latest Posts

Increase in DNS Based DDoS Attacks


Over the last few years, the Internet of Things (IoT) has expanded into all areas of our lives.A recent report predicted that there are over 8 billion devices potentially connected this year, whcih would grow to over 20 billion by 2020. Although the IoT will bring us many benefits there is also the potential for…

Read More

ISGMLUG Newsletter


SGML and XML are both languages that are used for defining markup languages. More specifically, they are metalanguage formalisms that facilitate the definition of descriptive markup languages for the purpose of electronic information encoding and interchange. SGML and XML support the definition of markup languages that are hardware- and software-independent, as well as application-processing neutral….

Read More

The New Technology Which Could Help Internet Speeds


What do you look for in a new property – big gardens, ample parking, close to amenities or simply a nice well built house. Well I saw a house last month in my home town and I very much wanted to move there.  Sure it wasn’t the nicest place and it was quite a bit…

Read More

IP Routing Functions


There is no doubt that one of the most important functions of the Internet protocol (IP) is that of routing.   The datagrams that are routed by IP can be generated either on the local host or another remote device.  If they are generated from a remote host, then in order to process the datagram it…

Read More

Introducing Snort – Open Source NIDS


Anyone who has studied or spent time working in network security will have heard of Snort.  It is an open source NIDS (Network Intrusion detection System) which has been installed on millions of systems across the world.  It was written initially as a packet sniffer by Marty Roesch but is now supported by many more…

Read More

UDP – User Datagram Protocol


UDP is a relatively simple protocol compared with something like TCP for one simple reason – it has none of the fields that ensure reliable delivery of information.  With UDP there is no guarantee that data transmitted will be delivered, the idea is that applications and other transport mechanisms will handle this function. However there…

Read More

DNS Caching for Proxies


Resolving names can often lead to performance issues on busy networks.  For instance in most large networks internet access is handled through central proxies, mainly for security reasons.  Organisations can control access to the internet if all traffic is funneled via a specific server, these can also be the only machines allowed through a firewall…

Read More

Authentication Systems and Techniques


Authentication is one of the most important parts of any computer system, application or network.  Without an adequate authentication method a network operating system will quickly become overloaded and insecure.  In the early days of computers a simple username and password would be sufficient, and although this is still the case in many networks more…

Read More

Capacity Planning for Proxy Servers


There is one factor which is crucial when we are considering capacity planning for a proxy server and that is the ‘peak load’.  This point will vary greatly between organisations or companies yet it is essential that it is first identified and measured correctly.  For some networks it might be first thing in the morning…

Read More

Network Troubleshooting – TCP Flow Control


This is the 2nd article in our series on troubleshooting network performance problems, in it we are going to look at another area which will help this function. Retransmissions and duplicate ACKs are part of TCPs functionality which helps prevent packet loss.  If you have network or server performance problems then it’s likely you will…

Read More

← OLDER POSTS