In this lab, I've got three Cisco routers running within GNS3 connected to a switch, which
in turn has NPM connected to it.
Here's my NPM server and as an example, I can ping 10.1.100.1.
which is router 1, on router 1 is an example, I can type debug IP ICMP and back on NPM when I ping that
IP address, I'm getting Echo replies sent on the router.
So the router is receiving the ICMP messages from the NPM server.
So I'll log in, under nodes, Cisco
I can see that I have three routers currently up.
So as an example, router 1 with IP address 10.1.100.1 is shown as up
and I can see some information about that device. Now, in GNS3 I'm going to start capturing
on the link from NPM to the switch, I'll capture traffic on a switch interface.
What I'd like to point out is notice ICMP messages from NPM, the server has an IP address of 10.1
100.100.
That's what we're seeing as the source in the Wireshark capture.
So Echo Ping request
and then here's a response from the router.
So as an example, I could filter for ICMP messages and what we could see.
Here's an example is ICMP message from NPM to router 2 and router 2 replying
we can also do a search for SNMP.
So in this example, we've got an SNMP message from NPM to router 3 opening that up
We can see it's a data request message.
It's trying to get this OID information.
Here's a response back from the router, more response information sent back, notice OID information.
So in the background, NPM is requesting information from the routers.
In this example, it's querying router 2, and router 2 is responding here
it's querying router 3 and so forth and so on.
That information is then displayed in a nice graphical format on the NPM server.
As an example, if I click on router 1, I can see information about this device.
I can see that it's up, see its IP address, see other information, including SYSOBJECTID last boot
I could even click on the Telnet link and launch a telnet application to Telnet directly to the device.