Snmp and NAT

Hello,

I am facing this scenario: three or more remote LAN (peripheral offices), with the same devices (printers, NAS) in each of them. Those LANs have the same network addresses, i.e.192.168.1.* (are connected to WAN via NAT).

I need to collect snmp traps from a central server (public IP).

Question: how can I distinguish traps sent from two devices in different remote locations? Suppose I receive a trap from printer HP2605 with IP 192.168.1.50: I have two or more printers HP2605, same IP, in different remote offices.
Which one has generated the trap?

If you think, even for a single LAN the proble arises: two or more identical laptops in DHCP, sending traps to a server: how recognize the device sending the trap, if IPs are dynamic?

Many thank for thinking with me.

Configure them to different 10.x.x.x subnet addresses?

Yep, I was trying to avoid this (you know, got to change everything, NASs, printers, access on SQL...)

Plus, some notebooks are moving from one site to the other, so a trap sent from one of them is hard to be caught).

I can't believe SNMP doesn't have a device unique ID when sending traps:eek:

You might write a proxy for them to report to, that annotates the event with the proxy outbound IP. If they log events locally, you could poll the logs to determine which called.

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I am thinking to cross relate the trap with the firewall access, on port 162. This could give the public IP of the remote office the trap has been generated from.

Traps should then be unique...at least if remote offices have fixed public IP.:rolleyes: