Common and potential problems

• You have an internal mail server and your users are receiving bounces when they try and mail particular destinations or your ISP has informed you that you are an open relay.
• Inversely one of your suppliers/customers cannot mail you and insists it's your system, and you need to find out what is really the cause.
• You are moving your connection {from one ISP to another or changing type isdn to adsl/leased line} and you want to ensure minimal down time for services such as mail etc during the changeover.
• You need to achieve some form of backup connectivity via a separate ISP/medium
• You have an internal mail server and you want to investigate methods of making users e-mail available to them at home or on the road, without having to change their settings regularly.
• You wish to move from a small peer to peer {workgroup type} network to a client server architecture for either internal/self managed e-mail, dhcp, dns, file and print services or any other.
• You have a firewall/proxy or some other security device/system but your needs have changed and you need to either re-design/re-configure your systems to cope with the new needs.
• Your systems are fine but you need to have someone available who is familiar with the setup in case something breaks down or is in need of re-configuration patching/updating.
• You decide to setup an internet web server for use in a hosting company or for internal hosting on a leased line.
• You have a complex WAN that has evolved over time and you believe that it could be rationalized to gain better performance/reliability or is already failing.
• You are a competent IT manager and you have already a plan for the re-design of your network and just need a more experienced resource to double check your plans for unforeseen problems, act as a sounding board and/or to suggest intermediate steps that could be take to reduce downtime during the changeover period.
• You have equipment installed and supported by a large ISP or other corporate, and their support is not satisfactory or they are sending out apparent trainees to re-configure your critical systems, and you need a more personal and consistent approach.
• You have heard about my linux and windows and router hardening procedures and you wish to be trained in there use/development/customisation.
• You need someone to find out the real reason why system X wont talk to system Y as both suppliers are claiming it is the others mis-configuration.
• You have a isdn router connection to the internet and your bills indicate it is dialling up more often than expected.