Don't have routers password, need to open ports

Hello, I've taken over a customer's entire network. I need to open a port on their router/firewall, however the previous IT manager didn't leave the username and password. So I'm not sure of exactly what ports are currently open and to where they are routed. Before doing a hard reset to the default settings, is there a way internally to test which ports are open and to where they are routed. This way, after I do the hard reset, I can reopen the previously open ports so the customer doesn't experience any issues. Or if anyone has other ideas, I'd be open for suggestions. Thanks.
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James HIT DirectorCommented:
What brand of router/firewall is this? With Cisco equipment you can reset the password without having to reset the device back to factory.
bhodge10Author Commented:
@Spartan, well that would be too easy if I knew the Brand and model. I guess I'll need to go to their office tonight.
Garry GlendownConsulting and Network/Security SpecialistCommented:
Many/most password recovery methods require physical access to the device, I doubt you'll be able to do much from a distance ...
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u need to do CEH Certified Ethical Hacker before doing anything with their network lolz,
Nmap (port scanner) is great tool for discovering open ports NMAP_LINK, it haw linux and win bynaries.. If you know router/firewall model, maybe previous admin leave default username/password for device

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