Our small IT company has just adopted a fairly large cisco network, with zero documentation. Aside from consoling into each switch/device and pulling a "show run", would any of you guys have recommendations for what I can use to get a handle on things? I've been told to see if CDP works/ is setup but what about SNMP and/or the Cisco Network Assistant?
There are also a number of VLAN's setup on a 6509 using a VTP V1 server (unsure of IOS version), that I'd like to push out to all of the other devices. I have tested with the 6509 (server) and a 2960 (client), matched all of the proper domain, mode, password, and set the VTP interface to the IP that's used on the management interface, but I can't get the 2960 to update with the VTP info from the 6509. Any and all information would be greatly appreciated and would certainly help. Thanks again.
if you dont have a proper diagram, first thing i am gonna do is prepare a good diagram. that will give good understanding about network and will be easier to take next steps. you can easily use CDP to gather connectivity details. first go through CDP details and create draft diagram and detailed map. then go to exact places and confirm all details are correct physically.
if there is zero existing documentation, of any kind, then i would recommend starting at the core of the network and work out to the farthest edges. You'll be able to build a device list with credentials, gather configs, IP layout, routing protocols, visios, etc.
That's about the best advice i can give, and i have been through situations close to this in my career. I've not had to start with zero documentation, but have been in situations where any existing drawings were completely out of date, no record of gear (types or versions), or about 50 different credential sets. it sucks and is very time consuming but i think you're just gonna have to roll up your sleeves.
If it's a fairly large Cisco network, and you, or anyone else at your company, isn't very knowledgeable about large Cisco (or other) networks, and especially if you don't have any documentation, I would suggest hiring or retaining (i.e. consultant) someone with the knowledge you need.
For example, you mention having VTP v1, and wanting to push it out, but many consider VTP v1 (or v2) a disaster waiting to happen (especially if you don't have the expertise to manage it).
BTW, certification, alone, does not always guarantee someone is really knowledgeable, beyond being able to pass a certification exam.
I have been in similar situations but I wouldn't say that they involved "large networks". I am curious about how large, how many switches? Generally when dropped into a no documentation situation I do what others have mentioned, start documenting from the core out. It serves 2 purposes, educate yourself on the network and leave your client with documentation so they aren't in this situation again. Depending on the number of switches you could console into each one or it is likely a good idea to get up to speed on something like Ansible. It may seem overwhelming but it will pay back quickly. https://docs.ansible.com/ansible/latest/collections/cisco/ios/