Multiple NIC's

[natedmac]

Hello,

Due to the way our previous admin setup our network, all of our webservers behind our loadbalancer cannot be monitored on anything other than port 80/443 as the back end connection cannot be reached unless you are on the local subnet.

I would like to be able to configure a second nic if possible that I can drop a connection on that local subnet and then be able to monitor services. I haven't found a good way for this to be done without using a separate instance of nagios. If possible please point me in the direction of documentation or any other ideas would be great.

Thanks
Nate

[mguthrie]

If these servers are allowed to send outbound traffic you could monitor them with passive checks.

http://library.nagios.com/library/produ ... -nagios-xi
http://library.nagios.com/library/produ ... -nagios-xi
http://library.nagios.com/library/produ ... -nagios-xi

[natedmac]

Unfortunately for these hosts, it wouldn't work as the way they are behind that loadbalancer it NAT's everything to a single IP and would be impossible to tell what host it is actually coming from. If it isn't possible for multiple nic's I will look into using a small instance that I can place on that network to then send the data back to the main host.

[mguthrie]

You could do multiple hosts with the same IP address if you give them different host names and have each host send passive results to Nagios. With passive checks, nothing gets initiated by Nagios, the results are simply sent from the hosts and they can run on a cron job. I may be misunderstanding your setup, but I think if the results are passive-only, that should work.

Host A
Address: 192.168.1.2
Host B
Address: 192.168.1.2
Host C
Address: 192.168.1.2
Host D
Address: 192.168.1.2

As long as all of these servers can send outbound results to Nagios, this type of set up would work.

[natedmac]

I will have to investigate it some more and see if I can get what monitoring I need setup.

[mguthrie]

Sounds good.