DHCP IP Scope

[kanandaguberan]

Hello,

 

Do anyone have an idea on monitoring the DHCP IP scope? We recently had an outage where there was no available IPs to be assigned. So, is there a way that we can monitor the left over IPs and alert when a specific count is reached? I did check the dhcp_response probe and we did not find an option for this as it pretty much monitors the response time only.

 

 

-kag

[Anon Anon]

Not the perfect answer, but in Windows DHCP server there are messages put  into the event logs that can be picked up by the evtlog probe, at least that's the way I used to do it. I assume devices will be able to be configured to issue syslog messages that could be gathered by the syslog gateway probe to do the same.

[kanandaguberan]

Hi,

 

Do you have the available event ID for this?

 

-kag

[Anon Anon]

Unfortunately not, I've moved on from the company where I had it configured, as I recall I used a combination of event ID and pattern matching in the message. A quick Google search has thrown up Event ID 1020 which sounds right.

[kanandaguberan]

Thanks a lot. I can work on the details of the event ID with my team here. Anyways, I will update this so that it will be useful for others.

 

-kag

[kanandaguberan]

The only thing to note in this case to see at what % free level it is going to throw this event ID.

 

-kag

[Anon Anon]

I'm sure the alerts started at 80% of capacity unfortunately I can't remember what the event message is as it's a couple of years since I was responsible for that system. I know I had it configured to warn at the lower level and that issue a critical on the out of leases message.

 

Google shows that the syntax of the error message is "Scope, 10.14.4.0, is 82 percent full with only 8 IP addresses remaining." and "Scope, 10.108.130.0, is 100 percent full with only 0 IP addresses remaining"

 

I hope this helps

[kanandaguberan]

That’s right. This event ID normally starts with a 80% which should be a good start. We can use some nas rules to escalate the severity when the it is >90%.

 

 

-kag