Now you may also want to disable CVP especially on internet facing interfaces.
In this example by simply enabling CTP on the face of the router I'm able to see a lot of information
on the local network.
So let's have a look at details.
Here's the command show CGP neighbors detail.
I can see as an example that there is a system a unified communications manager with the IP address
on the local network.
I could then simply connect to that server and see what I can do perhaps try and log in via trial and
error and eventually discover what devices phones and gateways are available on the server I could even
use this to access a device.
So as an example we can see that the phone is a Cisco DX 650.
If we're not sure what that is we can do a simple search in Google and we'll be able to find what kind
of device that is
this phone runs the Android operating system and then we could try and find vulnerabilities on to that
device.
So it's as simple as that for a hacker to determine which devices are out there.
He has a Cisco switch with its IP address and we could try and telnet to that.
He has the phone so Cisco IP phone DX 650.
He has another phone 79 70.
We can even see how much power that phone is drawing from the local switch.
And scrolling back we can see that the Cisco DX 650 is drawing this amount of power a lot of information
can be discovered through CTP and other protocols such as LDP.
You could look for vulnerabilities in a specific version of Iowas and then try and hack that device.
So on the scene to face we would type no-CD enable and that would disable CTP on that interface.
These entries in the table will eventually time out.
So have to wait until they hit zero notice as an example that Radu one on this interface has a whole
time of this value which is a lot higher than some of the other valleys.
In the output here the should be refreshed because we still running CTP on Foster Ethan at 0 0 but we
have disabled CGP on Fosset Ethan it is 0 1.
You can see as an example that at this point the call that he 750 has hit 93 seconds as a whole time
and eventually thats going a timeout.
You can also disable CGP globally by typing no CTP run.
I'm not going to do that now because I want to keep CGP running to the internal Jeana's three part of
the network noticed right one once again has refreshed whereas the other valleys are counting down and
I wouldn't bore you waiting for that.
They'll eventually timeout and be removed from the CTP table.
So the moral of the story is disable unnecessary services.
Use the command to check what's enabled on your Cisco device disable CGP on interfaces where it's not
required.
If you're connecting to an IP phone you may require CTP all in Calais a discovery protocol LDP but you
wouldn't need that on the Internet facing interface.
So disable what's not required.
While I was talking they noticed the thirty 50s hit zero as a whole time this phone has had to.
So that's not timed out so zero seconds and two seconds.
Next refresh interval.
Those of timed out.
And the same will happen for the remaining devices in the table.
They'll all eventually time out.
So here's the phone.
And if you wait a few more seconds notice we see the publisher now and eventually all we see is the
Rodda internally.