Summary

Once you understand the underlying technology of a network, reverse-engineering it isn’t hard—just tedious. However, getting an inductive toner set is a must if you have a lot of unlabeled cables.

From a network perspective, on a functioning network (that is, if servers are talking to each other and to workstations), there’s always a trail that you can follow, starting with the routing tables and the DNS. Don’t forget, application configuration can be very helpful.

SNMP is very useful if you have the community strings, but if you don’t, discovery tools are available. Although SNMP consoles’ network discovery agents can be a good starting point, rest assured that you will be doing manual verification. Finally, a good port scanner is your ...

Get Sams Teach Yourself Network Troubleshooting in 24 Hours, Second Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.