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Network engineer RRS feed

  • Question

  • what was the last problem that you solved as a network engineer
    Saturday, March 5, 2011 4:22 PM

Answers

  • what was the last problem that you solved as a network engineer

    Maybe not the last, but this is a representative problem:

    The company was using hardware tokens for two-factor authentication. This worked very well for local users, but when remote users attempted to authenticate from their laptops connected over the cellular network, the attempt failed. The log at authentication server showed the connection as being validated correctly, but still the software at the laptop displayed a message indicating that the attempt failed.

    After some investigation with a packet analyzer, I found that a UDP request packet was received at the authentication server, and another packet was sent back with the "OK", but the latter was never received at the destination. It turned out to be a routing problem; the routing tables allowed the packets to be sent from the remote network into the network that contained the server, but the reverse route was wrong and the response packets were not delivered to their destination. Adding an entry to the reouting tables fixed the problem.

     

    • Marked as answer by chand navaz Sunday, March 6, 2011 6:03 AM
    Saturday, March 5, 2011 7:06 PM