1)Buy or borrow a new Ethernet cable; plug it in, see if the problem goes away.
-
2)Buy or borrow a cheap Lan cable tester; It checks for continuity in all eight pins simultaneously, determining whether the cable, or one of the connected devices is at fault.
+
2)Buy or borrow a cheap Lan Cable Tester; It checks for continuity in all eight pins simultaneously, determining whether the cable, or, one of the connected devices are at fault. If you are lucky the Lan tester will identify crossover cables and estimate cable length too.
There are two things you can do:
1)Buy or borrow a new Ethernet cable; plug it in, see if the problem goes away.
2)Buy or borrow a cheap Lan cable tester; It checks for continuity in all eight pins simultaneously, determining whether the cable, or one of the connected devices is at fault.