[ec2] Nagios Issue

[Jim Cheetham]

On Tue, May 12, 2009 at 1:04 AM, Micah Walter <micahwalter at me.com> wrote:
> As mentioned in a previous email I am having some issue with installing
> Nagios. Everything seems to work just fine, but Nagios is reporting that my
> gateway is down. When I ping the gateway manually I also see it as being
> down.

Why do you think that is a problem? If *you* can't tell whether the
gateway is up by pinging it, Nagios cannot do any better. Either find
another way to monitor the gateway, or ignore it (and remove it from
the Nagios config)

Your basic problem is that the default installed configuration of
Nagios isn't correct for your situation. This has nothing to do with
EC2, or the Ubuntu EC2 images (and therefore is not really a target
for this mailing list).

> running smoothly. So, I am mostly curious about how the EC2 "gateway" is set
> up and why it would be unreachable...

It is very normal for only the actual administrators of high-demand
network equipment to be able to connect to them, or to ping them. The
gateway concentrates on doing its job (routing packets) and is not
wasting any time on extras (responding to pings from customer
instances). Many many pieces of network infrastructure are 'invisible'
to end-users (e.g. firewalls, network proxies, security devices, etc).
The only difference here is that the existance of the gateway is
declared in your IP stack configuration, that's effectively the only
reason that you even know it is present. Nagios has picked up on this
configuration when setting up its example config files.

Just configure Nagios to monitor the devices that you "own". If you
need to monitor other equipment (e.g. ISP gateways) it is customary to
ask first, however.

-jim