Hi I'm not a sysadmin but I have two FC11 boxes that are behaving strangely after the circuit breaker tripped (overload elsewhere - fixed). A can ping B but when B (or any other node on network) pings A I get 'destination host unreachable.
all nodes are connected via a managed L2 switch so its just a simple A---switch---B to get from A to B.
The firewall on B has been turned off for this test (prior to that it did allow ICMP inbound anyway, and it worked fine before the circuit tripped).
Its not just ping that doesnt work on B, I cant SSH to B either.
B is configured as software RAID 1 and I did check the array and it appears to be OK after the power came back
Notable history: When I restarted after resetting the CB, it took a LONG time for the logon screen to appear, there was lots of HD activity, and after it started up it only showed 'Other' as a valid user, my normal account was not listed. After rebooting it reappeared and the boot speed as back to normal but I cant access any services or ping B.
I'm not a sysadmin so I dont know where to really start looking besides the obvious (firewall, network connection, test other clients, restart comp, SMART attributes OK)
Appreciate if anyone can suggest where I should start looking.
Solved! Thanks to Wayne's list I've found the culprit, the L2 managed switch configuration got corrupted (I have no idea how?!) I switched ports around between the different clients and confirmed it.
It was so badly corruped I had to use the serial cable + minicom to reset it. It deleted all the trusted hosts aside from one ip that I wasnt connecting from (hence I was unable to telnet/web into it) and decided to block traffic in one way between A/B ports. Finding and fixing it was quite a frustrating (but educational) experience! I would never have suspected the managed switch would be capable of doing this.
Its a D-link DES-3000 series switch. I'm now wondering if it was a freak incident due to a surge perhaps, or if the switch is broken in some other bad way.... Thoughts? Should I replace it?