Age of Networks and Network Management

In this post, I explore the current state of network management, a powerfully mature discipline that emerged after going through many changes as networking evolved to its present state. Network management is still growing and evolving. That’s because network environments are still developing in sophistication, built-in support and changing device implementations like virtualized firewalls, switches and routers.

Evolution Has Been Swift

Binary synchronous communications (BSC), a link protocol, came out in the 1960s and was used with S/360 and S/370 computers, and is still running today in some computers. BSC worked well but when it didn’t, you didn’t get a lot of help figuring out what wasn’t working. Management is not mentioned in the 1970s version of the general introduction manual. People who supported BSC understood symptoms and mapped them to categories of problems like device problem or circuit failure. Later, protocols were developed and deployed like Basic Telecommunications Access Method, Queued Telecommunications Access Method and Telecommunications Access Method. These protocols came with macro interfaces for programs which made them useful to company programmers not just the hardware and software manufacturers.

VTAM and TCP/IP Changed Everything

IBM introduced VTAM with the System/370. VTAM has wonderfully detailed error descriptions, which were utilized by the network management products like Network Communication Control Facility and Network Logical Data Manager for problem determination. Thanks to the VTAM designers and developers, network management was possible to a new level of excellence. VTAM has diverse support for network protocols including SDLC, Token Ring, start-stop, BSC, local 3270 devices and later TCP/IP.

Parallel with VTAM from IBM, TCP/IP was developed and is now used everywhere. TCP/IP is occasionally known as the Department of Defense (DoD) model, because the development of the IP method was funded by the United States DoD. TCP/IP was used for projects within the DoD but today, if you have a wireless router in your home you have an IP network. The network address 192.168.2.1 is the default IP address for some home network routers. The routers come with network management tools that use TCP/IP management applications. Network management has reached the home user and is used to keep their network devices available and running well. We went from no management information and tools to management products for the home user is roughly 40 years.

Standards Are Used Everywhere

The thing that makes network management possible today is the plethora of standards that were created and have been adopted by companies. Without a standard way to understand what is happening in a network it is impossible to interoperate devices and to understand when something goes wrong. SNMP is an example of a management protocol. It’s used for collecting and organizing information about managed devices on IP networks and for modifying that information to change the way a device behaves. A wide range of devices supports SNMP including cable modems, routers, switches, servers, workstations and printers. SNMP is an element of the Internet Protocol Suite as defined by the Internet Engineering Task Force.

Products Abound, Many Built on TCP/IP Utilities

As networks changed, products were needed to manage them. Creation of these products was helped significantly by a set of TCP/IP troubleshooting utilities and protocols. Even though many people use TCP/IP every day without even knowing that these applications exist—much less how they work—they are critically important to those who maintain TCP/IP networks. Example of these utilities include:

• hostname, the TCP/IP Host Name Utility
• ping, the TCP/IP Communication Verification Utility
• traceroute, the TCP/IP Route Tracing Utility
• arp, the TCP/IP Address Resolution Protocol Utility
• nslookup, host and dig , the TCP/IP DNS Name Resolution and Information Lookup Utilities
• whois/nickname, the TCP/IP DNS Registry Database Lookup Utility
• netstat, theTCP/IP Network Status Utility
• ipconfig, winipcfg and ifconfig, the TCP/IP Configuration Utilities

Device Changes Create Challenges

Just as distributed servers have become virtualized, network devices have done so as well. For example, a virtual firewall is a network firewall service or appliance running entirely within a virtualized environment. It provides the usual packet filtering and monitoring provided by a physical network firewall. Virtual devices are part of virtual networks that can experience vulnerabilities just like those associated with a physical network.

For example, users on machines within the virtual network have access to all other machines on the same virtual network. The concern within the networking community is that the propagation of virtual devices presents even more computing images that can introduce the opportunity for vulnerabilities within a network. Virtualization of network devices has benefits like cost saving but creates new challenges and complexity for network managers.

Next week, I’ll continue the discussion of IT management with an exploration of the discipline of application management that emerged in the late 1990s and continues today with increasing focus.

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