Spent 2 ½ days trying
to figure out why a customer's VPN solution
was not preforming the way the vendor had promised. Never mind the fact that the networking team had
no say in the installation or operation of the solution. Spent one whole day
just tracking down the laundry list of issues the customer was having and any
troubleshooting steps the vendor and customer had done. The second morning we
traced the path checking routing and firewall ACLs. No issues, so I asked the
customer if I could have a client to generate traffic on demand (and also check
it’s setting). The customer was glad for any help and brought me a client.
Checked firewall and IP setting, no issues. The third morning the vendor was a little
upset that I was looking at the client, they were sure it was the network.
After some back and forth, their tech had to go to lunch, and created an
account on the server so I could do some tracert, ping, ect. 10 minutes late I
had it figured out.
So, 1st thing I did was a tracert to a connected
client, and what do I see……………….
I checked the server’s
IP settings and the subnet mask was incorrect, as soon as it was corrected ALL
the issues the customer had cleared up, even some they had but on the back
burner.
The clients have a /21 bit mask, and the server was using a
/24, the vendor’s tech swore up and down he had not changed it, and that it had been
working up to that point. He even wrote an email saying “How strange it was
that it stopped working now” I wrote back it was strange it had worked at all.
General troubleshooting steps
1. Define
the problem.
2. Gather
detailed information.
3. Consider
probable cause for the failure.
4. Devise
a plan to solve the problem.
5. Implement
the plan.
6. Observe
the results of the implementation.
7. Repeat
the process if the plan does not resolve the problem.
8. Document
the changes made to solve the problem.
