Cisco Catalyst 3650 - 48 poe switch - default IP Address?

[MarcLindstrom05743]

We have a Cisco Catalyst 3650 switch pulled out of a building.  I'm not sure what the configured IP Address on it is.  When I connect my laptop to it directly with the switch plugged into our Xfinity modem, I get online and get to a 10.1.10.X number (Xfinity number).  But I can't figure out how to find out the ip address of the switch.

Any ideas?  When I run an IP Advanced scanner, it doesn't show, and I guess that seems normal since it would be hard to believe the switch is on a 10.1 range

[balaji.bandi]

if you connected to Modem (Xfinity modem) and you getting IP address and you have internet access,. then Switch acting as Layer 2.

Get Console vable and connect to switch (Cisco Catalyst 3650) try on console you can see the config "show run"

if the device having issue, then you need to reset to factory to setup.

https://techdirectarchive.com/2019/07/31/how-to-reset-a-cisco-3650-catalyst-switch/

[MarcLindstrom05743]

So when we get the switch back into the envoirment, we can't get online anywhere.  Our setup is as follows:

ISP Provider (Modem)>8 port non-managed switch (has all WAPs connected)>48 port Cisco Catalyst 3650 poe switch

So the 8 port Unify switch, holds all the waps in place and providers IPs for all the devices connected.  But the RJ45 cable going from it, to the Cisco 48 port switch is connected and any device connected to the Cisco switch isn't getting online.

If I disconnect my computer from the Cisco switch and connect directly to the Unify 8 port switch, then I can get online with a 192.168.1.X IP Address.  Again, when I bring the cisco switch back into play and connect directly to the Cisco switch nothing, doesn't even pickup the connection.

Sounds like the Cisco switch has already been programmed or maybe trying to also be DHCP conntroller?

Sorry for all the explanation, all this IT stuff is newish to me, I do most AV stuff so trying to help the homeowner troubleshoot his equipment with limited knowledge

-Marc

[balaji.bandi]

thanks for the information, when you connected to Switch with PC, did you get any IP address.

either way to work this switch, you need to get access to switch either SSH or Console.

[MarcLindstrom05743]

So I'm not sure if the switch needed a second to turn on and get situated but now it's giving me an appropriate IP within the range of the other devices on the network.  The post originallty was me testing the switch at our office (10.1 network).

The house is on a 192.168.1.X network.  When I originally brought the switch back this morning and connected everything, my computer wasn't making an initial connection.  But after a few moments my computer went thru the process of acquiring and successfully getiting a 192.168.1.X IP Address.  So I'm able to get online now.

I'm a little confused how the homeowner has everything configured.  Because again he goes from ISP modem>8 Port Unify Switch (must be managed since it's giving out a 192.168.1 address?)>48 port Cisco switch

The reason he wanted to use both the 8 port and 48 port is because the 8 Port will be for the 5 WAPs he has throughout the house, while the 48 port will be for the Cat6 terminations/TVs throughout the house.  So he wanted to keep things seperated.  Personally I think he'd want to go into the 48 port switch first and then to the 8 port daisey chained from there.

But I stil can't determine what the IP Address is of the 48 port cisco switch.

So if I've got my laptop connected to the 48 port which goes to the 8 port which goes to the ISP modem and I'm getting a 192.168.1.X IP then it's the 8 port Unify that's giving me the DHCP or is that coming configured from the ISP Modem?

And I'm still not sure how to get the IP Address of the Cisco 48 port switch in case he needs to troubleshoot it down the road,..

Thanks again to everyone who's been replying, really appreciated.  I'm way above my pay grade here.

I don't know if I want to get into the Factory resets/etc at this point because things are working and the factory reset looks pretty intense

[balaji.bandi]

The Switch in Layer 2 , so that is the reason it as transparent to your other switch.

until get console cable and connect to device you will not able to know the inside config (this was mentioned last fea post)

if this was configured as Layer 2 there is no IP for the switch.

get Cisco console able and connect - my orginal document still show you how to connect to console to PC.

[MarcLindstrom05743]

The only document I saw was for factory reset.  I've got my cable connected directly from the laptop to console but I don't see anything popping up and I've lost my connection to the Internet

[balaji.bandi]

connecting console cable not going to lost internet, - you need to follow step by steps as suggested.

Command-Line Interface

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/hardware/quick/guide/cat3650_gsg.html#wp70225

here is video :

https://www.youtube.com/watch?v=d9Rxz8iwx1U

[Seb Rupik]

In addition to @balaji.bandi suggestion, a more forensic method would involve running tcpdump /wireshark whilst connected to one of the switchports where you *may* receive a CDP message from the switch. This will reveal the IP address of the switch.

If you are feeling determined enough, go through each switchport whilst running the packet capture and you *may* hopefully encounter a trunk port which *may* have the management subnet tagged on it. The VLAN ID will be visible on the the Ethernet frame. Configure your laptops network interface VLAN ID to match and by picking an adjacent IP you should be able to reach the switch IP. At this stage you will need to know the username/ password to login.

...probably easier to run the password recover steps...

cheers,

Seb.

[Georg Pauwen]

Hello,

reading through the posts, it looks like the switch is acting as a DHCP server, dishing out IP addresses in the 10.1.10.x range. These addresses are not NATted on the ISP modem, that is why you don't have access to the Internet.

Try and send a broadcast ping from your (I assume) Windows machine to 10.1.10.255 and check which IP addresses are responding. One of them is probably your switch.

It is also possible that the switch has an IP address in the 192.168.1.x range, ping to the broadcast address 192.168.1.255 and check which addresses respond, one of them could be the switch.

Then again, it is also possible that the switch does not have an IP address at all. It can only be assigned to the switch manually by configuring one of the below:

interface Vlan 1

ip address dhcp

or 

interface Vlan 1

ip address x.x.x.x