Testing Network Changes When No Test Labs Exist?
vvaduva writes "The ugly truth is that many network guys secretly work on production equipment all the time, or test things on production networks when they face impossible deadlines. Management often expects us to get a job done but refuse to provide funds for expensive lab equipment, test circuits and for reasonable time to get testing done before moving equipment or configs into production. How do most of you handle such situations, and what recommendation do you have for creating a network test lab on the cheap, especially when core network devices are vendor-centric, like Cisco?"
Step 1) Make a formal request for the test lab. Make it as detailed as possible. Explain the impact to business if various components fail. Make a plain-language executive summary calling out risks. step 2) Once the request is denied, make sure you have a paper trail of the rejection step 3) If possible test network changes on the production equipment at 2am so that impact on users will be less step 4) Once the inevitable failure occurs, haul out the paper trail and get the bean counter fired. Repeat until test lab is approved. Note, step 4 may get you fired instead. Business decisions are somewhat nondeterministic.
Here are a few tools:
GNS3 - http://www.gns3.net/ - free network simulator, based on Dynamips Cisco emulator
Opnet - http://www.opnet.com/ - detailed planning of networks, from scratch
Traffic Explorer - http://packetdesign.com/ - plan changes to an existing network