Top 5 Networking Issues with Windows Clients

by [Published on 3 Nov. 2009 / Last Updated on 3 Nov. 2009]

The 5 most common problems associated with Windows clients over a networked infrastructure.

Introduction

A network is defined as a group (2 or more) of systems such as Windows desktop and server platforms that connect together for the purpose of sharing resources. Typical resources include printers, storage devices and folders that include files and other data that users may wish to use. Networks are used to give centralized access (secure access) to networked resources and generally, the entire network (whether it be a home based office, or a corporation’s infrastructure) all connect up to the biggest shared resource in use today – the World Wide Web. Tie all of these dissimilar systems and resources together and you can start to see why so many people have issues connecting to, staying connected to or just plain ‘setting up’ their networks. Keeping a network operational after it is created is another challenge – especially when you start to use it over unsecured connections.

The problems many people; such as end-users, administrators and business owners face today are usually common. For example, how many times have you heard ‘I cannot connect to the network’ or something of that nature? This is because since Windows systems came to the market, they have never been easy to set up and work with and worse, keep problem-free. Now, tie in the fact that many people have moved, tried to use, or otherwise integrated other types of systems such as Apple, Unix or Linux on their networks, you can see why more and more issues arise each and every day. As well, there is a huge mobile market growing by leaps and bounds. These same users now wish to connect their mobiles such as Blackberry’s, iPhones and Palms to their home or corporate networks adding a new layer of complexity to the mix. To complicate things further, wireless (not a new technology) is a booming market growing bigger than ever with newer, faster and more secure technologies (such as 802.11n) which seem to come to market yearly and bring a new host of issues to the ‘connectivity’ issues you may already face. All of these technologies, systems and resources once connected (and that is, if you connected them correctly), now suffer from many of the same issues.

This article lays out what seems to be most common of these problems and I provide some helpful tips to give you ideas on how to troubleshoot or circumvent just about any common network issue you may find. This article focuses on Windows Networking problems. With Windows client systems (such as Windows XP, Vista and 7), you will find that these top five issues are absolutely the most common amongst most Windows users today. These are not listed in any order – they are all equally to blame or all should be equally considered because they all work together to produce the same result – a network that operates correctly, or one that is expensive and does not do anything for you.

# 5: Initial Configuration

The first problem that comes to mind is glitches that occur when configuring your network, your systems and resources for use. There are many components to a typical network and as size and use grows, so do its complexities and the possibility for problems to arise. With the rise in telecommuting over the past 10 years, and the growth of this market in terms of hardware and software offerings, there are many people setting up systems and networking them together without any formal education on the topics or systems, networking and security.

No matter whether you are setting up and configuring Windows, or a Linksys router, there are many things that need to be considered and done correctly. There are also multiple ways of doing things, and so, the best practices should be considered and followed. For example, the computer system you want to connect to the Internet. This simple example requires you to know a few things about TCP/IP addressing schemes, the DHCP protocol and cabling (or wireless for those who have it available). A great primer to networking can be found by following this link. Here you can get an idea of the complexity of networking if you are not already familiar with the fundamentals.

When setting up your systems, the biggest things that cause disruption are loss of your main power source, incorrect cabling (or wireless configurations), lack of/or misconfigured protocols (such as IP) and problems with Windows systems such as misconfigured network services. Another issue to consider is the configuration of how your client computers access shared resources, such as a network printer. Many times, a ‘server’ is used to provide centralized access which would mean you would need to configure properties on the print server, or if the print server function is located and controlled on a server, the configuration of the workgroup, or client/server relationship. This is a huge stumbling block for those working with networked Windows systems… the relationship of a client to the server it uses to work with shared resources. After the initial configuration and testing of your network, the next steps should be to document it correctly so that if problems do pop up, you have the phone number for your ISP handy, or the manuals (or Web links) to the systems you are working with.

I have also found that people put expensive Band-Aids on mere flesh wounds. For example, major corporations that apply a tool like a packet queue accelerator – when all they needed to do is assess the amount of bandwidth being used on their network with a network performance monitor and cleaning up issues with applications, poor design or otherwise.  

If you decide to use wireless connections over wired ones, initial design and configuration must not be overlooked. The OSI Model is a great help in getting these issues resolved. Firstly, wires (or cables) are associated with problems at the physical level. The cable is either damaged or being affected by distance or electrical problems, is connected incorrectly (wrong type or grade), or possibly the fact that the cable is simply not fully connected. Signal Interference issues are common, especially when cables are laid over a light or power source, for example. Wireless connections are way more complicated, as they need multiple hardware as well as software components (such as drivers and applications software) to be configured, made to work and keep up and running. Many times, you need to configure an Access Point (AP), generally found on most home-based routers sold on the market today.

# 4: Credential, Permission and Rights Problems

So, if you configured everything correctly and connected all systems without issue – then what could possibly go wrong? Anything and everything. The first problem that comes to mind with Windows systems is credentials, permissions and rights. Most times, you may try to access a host and not be able to because… yep, you guessed it – because they can not log in, or they do not have permissions to access resources once they are logged in.

Usually, someone knowledgeable in this area (a systems or network administrator, for example) may have configured this for you. If you did it yourself, you really need to consider a few things. First, Windows systems generally force you to change your password periodically. Or, over times of inactivity, accounts become stale or passwords forgotten. If this happens to you on your home or corporate network, you can either contact your administrator to fix this, or fix it yourself. To do so, simply access your account and login information within Windows to adjust what needs fixing. As well, you may be using a workgroup without a centralized source of access control and have to log in to multiple systems to simply use a resource. Workgroups create many problems because of this and are not recommended for computer networks ranging in size of 10 systems or more.

You can use the Windows Event Viewer to find most of your problems in this area, if you can log on and check it. It's recommended that you store a password in a safe place in case you forget, but never leave a credential set (username and password) visible for anyone to locate and use without your permission. Not being able to access resources over your network is a common issue and easily resolved with a better design, or a contingency plan to recover lost of forgotten credentials.

# 3: Network Performance

This is by far the most common issue with networking in general. With Windows, performance can be affected in many ways. For example, if you build or buy a computer system without taking into consideration the applications you will run across the network. The most common applications are any type that requires a client to server relationship, which means the client installed on the Windows desktop must interface and transmit data over the network in order to function. If network performance is impacted, either the network is too slow (very common term), or the application was not developed with the network in mind. It can be confusing to solve this type of issue and normally requires advanced analysis of the problem usually needing a tool such as a packet analyzer (known as a sniffer) to solve.

Speed and Latency issues can be the result of slow connections, or from a network that is saturated with data. For example, if you use gigabit Ethernet between your hosts, cabled connections will give you up to 1000 Mbps of speed. Unbeknownst to some, switching to a wireless connection will drastically impact your network communication because today home-based wireless systems (even when teamed) will not produce more than about 54-100 Mbps of transfer. Add in interference and you will definitely feel the pinch. 

Also, using a hub instead of a network switch (that keeps a switching table in memory) can cause major issues with speed and latency. Using non-hierarchical designs where the core of your network is operating at the fastest speed and the access layer into the core operating at a slower speed can and absolutely will create bottlenecks. Although this is not a common design for home-based networks, you would be surprised at how many SOHOs have grown in size to really need a good design to operate correctly. Mismatched speeds and duplex settings on NIC cards such as half-duplex to full duplex (and auto-sense) are also common issues that create a performance hit on your network. Lastly, using a switch and creating a loop will likely shut your network down completely if one exists.

Common to home based users using Windows systems, is Internet problems. If you have checked over your hardware and software and still cannot resolve the issue, it is likely it is not an issue at all. Sometimes, you may have an issue with a provider’s service. Contact and engage your provider if you think that there is an issue, because if you are paying for a service, it is also likely that you have an SLA in place. The SLA, or service level agreement, states that you should get a certain amount of bandwidth and uptime from them as well as a support network where you can contact experienced techs that ‘should’ be able to resolve your issues with you, or for you. This is not always the case. SLAs are in place to ensure that you get what you are paying for, so make sure you verify them! After speaking with your provider, it should be apparent whether you are working for them, or they are working for you. Just because a link is cheap, or expensive – this has nothing to do with the quality of the network, the support staff that manages it, and the support staff that manages you – the customer. You can also run your own tests. Test your connections, see what you have available and try to find out what you are currently using:

Other issues that relate to performance are security problems (such as Malware, covered later in this article) that tie up your systems resource, or purposely cause your services to fail. Lastly, you can easily have a problem that occurs outside your ISP’s realm. For example, if you were trying to access a Web site in Africa, you may find that the ‘hop count’ (which is defined as how many routers your packet traverses to get to and from its intended destination and back to the source) can be extremely lengthy. Just like it would take a plane a long time to fly from NY to Capetown, a packet has to travel the same distance and can run into problems along the way. You can use other tests such as Windows tools – ping, traceroute, netstat,and  pathping to find and pinpoint network issues.

Internet browsers can also cause an issue (especially if they are infected with a virus) so make sure that this is not the case, or that your systems browser settings are restricting sites… for example, with the newest versions of Internet Explorer, if you apply all security settings, such as a Phishing filter, the time it takes to verify the site for you adds seconds on to your access to the site which also could resemble a network issue. Remember, there is a reason why people blame the network for all of their problems – that is because it is simple to point the finger at the most obvious target. Just remember that the network is only a part of what could be causing performance issues. System resources, bandwidth and a lot of other issues could be causing slowness. Just running multiple applications and services over a link that cannot handle it will cause your system to freeze up if the applications respond poorly!

# 2 TCP/IP and other Protocol Problems

There are many reasons why this can be an issue, to name a few – ISP-based protocol issues, DHCP, APIPA, DNS, IP addressing and/or using a different protocol suite other than TCP/IP within your network. You can solve most of your TCP/IP related problems by a) having an updated document of your topology, even if it is a few systems. Being able to view a graphic (like figure X) is extremely helpful when trying to resolve a network issue, or, to quickly add a new host to your network without causing an issue. Even if you use DHCP, it is important to consider how IP tools like tracert, netstat, ping and pathping can help, but there are others you can use when not solely working with TCP/IP-related problems. Other protocols do exist and tools are available to perform the same functions to test them. At a high level (usually corporate networks), IP packets are routed over multiple devices and links which takes the problem and multiplies it times the amount of gear you are using. Routing tables can get screwed up from duplicate entries, and if address space is not summarize correctly, could cause large route tables, both causing performance issues for any end-user just trying to download a spreadsheet from the corporate office location.

If you do not have a network protocol configured, you will not be able to communicate over a network. Within the TCP/IP suite are many other protocols, such as DHCP (Dynamic Host Configuration Protocol) and DNS (Domain Name System) are common culprits for network connectivity problems – as well as for network performance problems. For example, if your client computer cannot speak with the DHCP server which provides it with its IP information, it will not function at all and be disconnected from the network. If this happens, APIPA (Automatic Private IP Addressing) kicks in giving the client a different address number (likely un-routable or un-routed within your network) causing confusion if you are unsure as to what this is. Clients are trying to communicate. If physical connectivity (such as cables and power sources) are disconnected, then you will not communicate. If you cannot log into your system or resources available on the network, you cannot communicate. If your system is configured with the wrong protocols, or no protocol at all – no communication. If your system protocols are not configured correctly, you are not able to communicate! Sometimes however, you may have limited communication that will affect your performance.

DHCP can cause performance issues if clients cannot locate a server in which to get an address lease from. What is DHCP is handing out a DNS server address to clients that has been decommissioned and the client has to search a list of servers to find one that is responsive. This adds performance problems to the mix. DNS is extremely difficult to find as the cause of a problem if you do not understand how DNS works with your system, you can check it out for yourself. Let us say you wanted to access www.TechGenix.com, for sites such as this, your client computer would need to have an IP address to communicate with (and through) your ISP. As well, it would need to know what DNS servers to ask ‘what is TechGenix.com? If these servers are taxed, or if there is a problem with the site itself, how would you pinpoint the cause of the slowness, or connectivity problem? Simple – you can do a couple of things to remedy this situation. First, it Is a fact that some ISP’s have problems with their DNS from time to time, so, the way around this is to configure a different DNS server to troubleshoot your ISPs problems. For example, you can open a Command Prompt (cmd) and use nslookup to find your current DNS settings. If you are connected to the Internet, your ISP will supply this info from a DHCP server. If the ISP then changes their DNS server (the primary as an example), your client may not reflect that information until your lease expires, or you manually try to apply for a new lease. You can try to release or renew the lease to test this theory. Or, you can use nslookup to change your primary DNS to use and test with a different one to see if the DNS server is the issue.

Change the server address using the nslookup command or add them in the network properties dialog box. Slow, unresponsive or problematic DNS problems can be tested quickly. For example. Use the following sites for help in selecting and entering a new DNS server:

DNS Servers:

If your speed increases dramatically, you now know what the source of your issues was.

Dynamic DNS is also an issue if you configure it manually and configure it incorrectly. WINS – well, if you are still using WINS (especially at home), then you are officially a dinosaur, but if you are – this can also cause slow performance if you do not try to resolve it with a cleanup of your records, or trying a different server. Remember as we mentioned earlier, if the server has a problem with its CPU (underpowered), you will feel it at your client!

# 1: General Security Concerns

The #1 networking issue when dealing with Windows clients is the poor application of basic security services and features - or lack thereof. For example, your system may get a virus (or other type of Malware) that causes the network to fail… or, ties up your systems resources so intensely that you cannot even browse a Web page. It is a fact that most of the intrusions over your network come from within the network, or very easily over wireless connections. This is seen more so with home offices and small companies that cannot afford (or are oblivious to) enterprise security solutions used to control, monitor and lock down wireless usage. That does not mean that your home PC, or router cannot be ‘secured’. The benefits you get from most hardware and software sold today is that almost everything you get now comes with some form of security features. Routers are now firewalls, IDS (intrusion detection systems), and provide detailed logs of everything going through it. A common form of attack is intrusion. An example would be, someone surfing (or roaming) your neighborhood (or a neighbor themselves) jumping on an open wireless connection and using your resources (such as the internet)

It should be mentioned that applying wireless security is not simple – older technologies such as WEP keys are easily cracked with easy to find hacking tools readily available for download over the Internet. Other ways to secure a wireless network (aside from WEP) is to use MAC addresses of the clients in your office that are on a list the access point maintains so that only those users have access. Again, not bullet proof, but every little bit helps if you have not applied any security at all to your system.

Whether using the Windows Firewall, or some other third party software offering, you should always consider using one as the most basic form of host protection. Network based intrusion detectors can help trend data and lock down anything that seems ‘fishy’. Defense in Depth should be considered and this concept is simple to understand. When you apply multiple forms of protection, you are applying defense in depth.

The router you use may have firewall capabilities, amongst other things (VPN/Encryption), IDS, Wireless AP with security features. Use them to your advantage and pull logs frequently to see what is going on. The systems firewall (Windows Firewall) is also able to perform this function at the host level.

Antivirus (as well as Network Access Protection, or NAP) can be used to reduce connectivity and performance issues. Most viruses today (as well as worms) operate to do the host system, or network harm. If 35 computers on a network that was barely able to hold its own load now get infected with a worm, it’s likely the network will slow down to a crawl.

The most important thing you should take away from this #1 problem (or concern) is that security when applied needs to be tested… and then monitored. Unless you have someone doing it for you in real time, its recommended that you apply multiple security features (which is the concept of defense in depth) and review your logs that come with them at least as often as you are concerned to check them.   

Also, make sure that at home you use common sense. Streaming music, video and whatever else while working on your computer impacts your network performance. You should never do this while working in a corporate network (since it’s not your network, it’s the companies!) and likely is already locked down. If you are responsible for a corporate network, you should really take steps to lock this down because trying to run IP phones successfully across a pipe that’s also servicing 30 people’s daily music feed either crashes your calls, your network entirely, or causes you to spend money to upgrade your link speeds, router hardware and so on.

Summary

The overall goal is to be able to troubleshoot your way through these top five issues and find the ‘root’ cause of your problem – this way you can resolve the exact problem and not just try ‘anything’ to find the problem. It is literally like finding a needle in a haystack. As you can see, working on a network can be confusing to troubleshoot and just because someone says the network is slow, it does not mean that their desktop is not the problem – it means that more analysis (detective) work needs to be done.

Links:

Speed Test Sites

DNS Servers

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