Network maintenance tasks are those tasks which network administrators perform on a day-to-day basis, allowing for the upkeep of the network. Some of the more common network maintenance tasks include, but are not limited to, the following general activities:
- Installing, replacing or upgrading both hardware and software
- Monitoring, tuning and optimizing the network
- Documenting the network and maintaining network documentation
- Securing the network from both internal and external threats
- Planning for network upgrades, expansions, or enhancements
- Scheduling backups and restoring services or the network from backups
- Ensuring compliance with legal regulations and corporate policies
- Troubleshooting problem reports
- Maintaining and updating device configurations
Installing, replacing or upgrading both hardware and software
Hardware and software installation, replacement and upgrades are very common network maintenance tasks. In a Cisco internetwork, this may include replacing older or failed hardware, such as switch linecards and supervisor modules in Catalyst 4500 and 6500 series switches, for example, as well as upgrading the Cisco IOS images to current revision or patch levels for routers and switches alike.
Monitoring, tuning and optimizing the network
One of the core facilitators of an effective network maintenance solution or strategy is proactive monitoring. Proactive monitoring allows potential problems to be detected and remedied before they cause an outage or affect operation. Event logging and network monitoring can be used to proactively react to network or system alerts and be used to do the following:
- Verify the performance of the network and all internetwork devices in the network
- Baseline the performance of the network itself
- Understand the amount of direction and traffic flows in the network
- Identify and troubleshoot potential network issues
Documenting the network and maintaining network documentation
While most network engineers consider documentation a rather mundane and even lowly task, it is important to understand that documentation is a critical component of network maintenance as well as troubleshooting and support. It is important to understand that different organizations have different standards for acceptable levels of documentation. There are several guidelines or recommendations that you should follow when documenting the network:
- Determine the scope of responsibility
- Understanding the objective
- Maintain documentation consistency
- Make sure that the documentation is easily accessible
- Maintain the documentation
The first guideline is ensuring that you understand your scope of responsibility. That is, it is important to understand what it is that you are responsible for. For example, you may be working in an organization that has a voice, security, storage and network team all under the Information Technology (IT) department umbrella. Rather than attempting to create documentation for all the teams, you should make sure you should only document those networks and devices that are within your administrative responsibility.
It is important to understand what the documentation will be used for. A common mistake that is made by network engineers is either including too little or too much information within the documentation. Take time to fully understand what the document you are creating will be used for and take into consideration the audience the document is targeted to and what information would be useful or excessive for that particular group. Over-documentation makes documented information hard to understand. On the other hand under-documentation makes network support and troubleshooting difficult to perform.
Consistency when creating network documentation is a key component that should be adhered to as much as possible. In most organizations, design and documentation templates are available for reference when creating new documentation. Maintaining consistency increases the usability of those documents and makes them easier to understand for everyone else.
No matter how great the documentation that is created is, it helps no one if the documentation cannot be accessed by those that may need it to support troubleshooting or support functions. Where possible, documentation should be stored in a location that is readily and easily accessible to all those that may use it, such as on a secure network location or share. In some cases, depending on the organization, it may be necessary for documentation to be stored in a secured, offsite location for disaster recovery and business continuity purposes.
And finally, once the documentation has been created, it is important to ensure that it is always maintained and up-to-date. Network diagrams from years ago may contain misleading and incorrect information that may hamper troubleshooting information. Network documentation should be considered living documentation that changes at the same rate as the network. Following the completion of each network project, existing documentation should be updated to reflect the changes that were made to the network.
Although there are no standards that determine what information should and should not be included in network documentation, most organizations and businesses have their own standards for what should be included in the network documentation. It is important to adhere to these standards and guidelines when creating documentation. From a best practices perspective, network documentation should include the following information at a minimum:
- Information about the interconnects between devices for LAN and WAN connections
- IP addressing and VLAN information
- A physical topology diagram of the network
- A logical topology diagram of the network
- An inventory of all internetwork devices, components and modules
- A revision control section detailing changes to the topology
- Configuration information
- Any original or additional design documentation and notes
- Data or traffic flow patterns
Securing the network from both internal and external threats
Network security is an integral component of network operation and maintenance. It is also very important that consideration be given to both internal and external threats. While most organizations have a dedicated security team, monitoring and a structured maintenance approach can also be used to discover vulnerabilities or potential security threats which can then allow for the appropriate action to be taken before an incident occurs.
Planning for network upgrades, expansions, or enhancements
Using network monitoring, you can identify potential issues before they arise as well as plan for possible network upgrades or expansions, i.e. capacity planning, based on the identified potential issues. Effective planning can be used to define the maintenance tasks required on the network and then prioritize those tasks and the order in which they will be implemented.
Scheduling backups and restoring services or the network from backups
Backups are a routine maintenance task that is usually given a very low priority. However, it is important to understand the important of backups – especially when attempting to recover from a serious or critical failure of the network. Backups should therefore be considered a core common network maintenance task, and should be allocated a high priority. It is important to ensure that backups of core network components and devices are scheduled, monitored and verified at all times. Having up-to-date backups of core devices can assist in the faster recovery of the network or individual network components following hardware or software failures, or even data (configuration) loss.
Ensuring compliance with legal regulations and corporate policies
A structured network maintenance methodology also ensures that the network is compliant with both legal obligations as well as corporate policies. Regulatory policies, which are mandatory enforcements of compliance with industry regulations and laws, will differ for businesses. Regardless of the industry and the requirements, it is important to ensure the business is following the industry standards as regulated by the law. Unlike legal regulations, corporate policies will vary on a business-by-business basis; however, it is still important to ensure that the network adheres to these policies and can provide the required functions.
Troubleshooting problem reports
Troubleshooting problem reports is core network maintenance function. While troubleshooting methodologies are described in detail later in this guide, troubleshooting is simplified by a structure network maintenance approach, which includes documentation, backups, and some form of proactive monitoring system.
Maintaining and updating device configurations
Configuration changes are common because of the day-to-day moves, additions, or changes (MACs) within organizations. Device configurations may also change due to scheduled maintenance tasks and planned changes to the network. For this reason, maintain and updating device configurations is considered a core network management function. Each time configurations on devices change, they should not only be documented, but should be saved both on the device and to an alternate backup location, e.g. an FTP or TFTP server (if one is available).