Using a Syslog Server

Most networks of any size need to have some sort of system for storing and managing their log files.  Most network devices produce logs and many of them can contain lots of useful information.  However without a way of analysing and reporting this data then it can simply become another system administration chore with little or no benefit.

One of  the oldest methods of centralising these system messages and logs is by using a syslog server.  Syslog messaging was originally used on UNIX system for the logs produced by network devices, applications and operating systems.  Most modern network devices can be configured to generate Syslog messages which can be picked up by a server.  These messages are normally generated and then transmitted using UDP to a server running a Syslog daemon that can accept the messages.

Over the years more and more devices have been created which cab support and generate Syslog messages.  Despite being fairly old technology many firms have started to move away from specialized technology towards simply using a central Syslog server to receive, store and archive messages generated from network devices.   These servers can also be used to create automatic notifications if specific critical events are generated – for example if an important default gateway becomes unresponsive.  This means that IT support personnel can be made aware of potential issues quickly and often before it affects users directly or at least minimize downtime.

Although there are many other methods of receiving and sending system messages across a network using Syslog has many advantages.  For a start it works directly with many reporting technologies and almost all network devices will support the Syslog message format.   This is very important because as soon as you have multiple logging formats and messaging you’re faced with  the prospect of installing multiple system log servers.  This creates a hierarchy which can be difficult to support especially for network support staff who need access to all logs in order to troubleshoot issues.

For example if you have a RAS (Remote Access Server) which is configured to use a different system messaging system from other devices in your network you could miss vital pieces of information.  In addition, problems in these servers can be missed and so important devices can suffer longer periods of downtime.    Many remote users rely on having access through a good VPN service when travelling in order to connect back from remote networks.

If you do have different devices which don’t support the Syslog standard and aren’t able to get rid of them there are some other options.  You can use software like Microsoft’s Log Parser program which can convert many formats into a log message that Syslog can understand.

James Hawkings

Author of a Polskie Proxy

 

No Comments Networking, VPNs

Protecting Your Network with IDS

There is little excuse for not installing an IDS (Intrusion Detection System) on your Network, even the usual culprit of budget doesn’t apply.  In fact one of the leading IDS systems called Snort is actually available completely free of charge and is sufficient for all but the most very complex network infrastructures.    It is virtually impossible to effectively monitor and control your network, particularly if it’s connected to the internet, without some sort of IDS in place.

There are certain questions about the day to day operation of your network that you should be able to answer.  Questions like the following will help you determine if you really have control over your network and it’s hardware =

  • Can you tag and determine how much traffic on  your network is associated with malware or unauthorised software.
  • Are you able to determine which of your clients do not have the latest client build?
  • Can you determine which websites are most popularly requested.  Are these requests from legitimate users or as a result of malware activity.
  • Can you determine which users are the top web surfers (and is it justified).
  • How much mail are your SMTP server’s processing?

It is surprising how many network professionals simply wouldn’t have a clue about obtaining this information from their network however, it’s impossible to ensure that the network is efficient without it.  For example a few high intensive web users can create much more traffic than the majority of ordinary business users.   Imagine two or three users in a small department who used a working BBC VPN to stream TV to their computer 8 hours a day.   The traffic that would generate would be huge and could easily swamp an important network segment.

All security professionals should ensure that they have the tools and reporting capacity to answer simple questions like this about network usage.   Knowing the answers to these questions, will help control and adapt your network to meet it’s users needs.   Of course a simple IDS won’t provide the complete solution but it will help keep control in your network.  Malware can sit and operate for many weeks in a network which is not monitored properly.  This will heavily impact performance and can enable it to spread to other devices and eventually other networks.  In network environments where performance is important, then being aware of the sorts of situations can make a huge difference.

John Williams

Network Professional and Broadcaster on author of BBC News Streaming.

Using Proxies for Virtual Locations

For many people, travel is becoming much easier and as a species our geographical horizons are perhaps wider than ever.  Inexpensive air travel and soft borders like the European Union means that instead of just looking to work in another city or town, another country is just as viable.  The internet of course enables this somewhat, many corporations have installed infrastructure to allow remote or home working which means many people can work from wherever they wish.   Instead of sitting in cubicles in vast expensive office space, the reality is that people can work together just as easily using high speed internet connections from home.

Unfortunately there are some issues from this digital utopia, of which most are self inflicted.  Instead of being a vast unfettered global communications medium, the internet in some senses has begun to shrink somewhat.  Not so much in size but rather an increasing number of restrictions, filters and blocks being applied to web servers across the planet.  For instance the company I work for has two main bases one in the UK and the other in Poland, which means there is quite a bit of travel between the two countries.  Not surprisingly employees who are working away from home for some time, use the internet to keep in touch with their homelife, yet this can be frustrating.

A common issue is the fact that many websites are not really accessible globally, they are locked to specific regions.  Take for example the main Polish TV channel – TVN, it has a fantastic website and a media player by which you can watch all their shows.  However a Polish citizen who tries to watch the local News from Warsaw from a hotel in the UK will find themselves blocked, the content is only available to those physically located in Poland.  It’s no one off either, this behaviour is shared by pretty much every large media company on the web who block access depending on your location.

There is a solution and for our employees it’s actually quite simple, all they need to do is fire up their VPN client and remotely connect back to their home server in Poland.  The instant they do this, their connection looks like it’s based in Poland and all the Polish TV channels will work perfectly.  There’s a post about something similar here – using a Polish proxy to watch TVN and some other channels although this one is through a commercial service designed to hide your location.  It’s a practice that is becoming increasingly necessary, the more we travel the more we find our online access is determined by our physical location.

The use of proxies and more recently VPNs allows you to break out of these artificial intranets which companies are creating by blocking access from other countries.  The idea is that if you have the ability to switch to various VPNs across the world you can effectively take back control and access whatever website you need. Your physical location becomes unimportant again, by taking control of your virtual location you have an huge advantage over other internet users by choosing the location you wish to appear from.  There are even some other options now take a look at this UK DNS proxy which does something fairly similar and can be used to watch the BBC and Netflix from outside the UK.

John Hammond

Author of – Does BBC Iplayer Work in Ireland 

VPN (Virtual Private Network)

The technology sector is at the moment somewhat confused about what a VPN actually is.   However the confusion is understandable as the VPN has continually evolved over the last few years into a somewhat different networking technology.   In the passed, the VPN could be described as a private network which is able to carry voice and data usually built into existing carrier services.

This is not how a VPN is defined commonly today, it’s probably best to split into the following different definitions.

  • Voice VPN – a single carrier which handle all the voice call switching.  The ‘virtual’ in VPN here implies that a virtual voice switching network has been created within the switching equipment.  This is probably the most dated definition under the concept of traditional carrier based voice vpns.
  • Carrier Based Data VPN – Traditional packet, cell switching and frame networks normally carry data in discrete bundles which are then routed through a complex mesh of networks and switches to their destination. These networks would be shared between many owners and users.   A VPN would be a web of individual virtual circuits which form a virtual private network over another carriers packet-switched network.
  • Internet VPN – this is probably the definition which is most relevant today, similar to the previous carrier based data network.   Here an IP network is the underlying transport and the common medium the shared hardware of the internet.

The internet VPN like this is the most common today probably because it is by far the easiest and cheapest one to set up.   There might not be the same bandwidth and data quality guarantees than a traditional virtual circuit, however the popularity of simple VPN client and server accessible from anywhere in the world is a powerful tool for many reasons.

What’s more the internet VPN can be created and used by almost anyone without exception.  Companies for instance will often install generic VPN client software on their laptops so any employee can dial in to the corporate servers using any internet connection safely and securely.   This means that employees can work remotely from almost any location all they need is a simple internet connection and an account on the VPN server.

A decade ago these were used over simple dial up modems but now most countries have a fairly large internet access infrastructure allowing high speed access from most public places and from home internet connection.   The other advantage is that an internet VPN requires no real investment in hardware apart from the central server.  Users can leverage the internet connection of their ISP or even a hotel wifi access point, a fairly insecure setup but if you connect through a virtual private network then all your data is securely encrypted and protected from prying eyes.

John Hammond

http://www.proxyusa.com/