DHCP service and wizard

[justine]

We monitor TCP Service (tcpsvcs.exe) in one of our DHCP server. It was in Windows 2003 before. But after moving the server to Windows 2012r2, this service is not found by nagios anymore. Do you think TCP Service is important to monitor?
Btw, I tried DHCP wizard, but got this error: Critical: No DHCPOFFERs were offered.
Please help. Thanks.

[abrist]

Do you think TCP Service is important to monitor?

Depends.

Btw, I tried DHCP wizard, but got this error: Critical: No DHCPOFFERs were offered.

Some DHCP servers will only offer leases to specific physical addresses. Do you know if there is such a limitation with your server?

[jdolley]

I have the same issue with Window Server 2008R2, No Offer. All clients can get an IP, the wizard is not very helpful on the settings.
How is Nagios asking for an address? It is not clear:

Server address: The IP address of the DHCP server a response to expected from. Leave blank for any server (What does this mean, response to expected from?)

Requested IP Address: The IP address expected to be given by the DHCP server. Leave blank for any valid address. (Should i put in a MAC address and preset a reserved IP? How would I make up a MAC address?)

Jim

[abrist]

I have the same issue with Window Server 2008R2, No Offer. All clients can get an IP, the wizard is not very helpful on the settings.

Can you run the check from the cli with the very very verbose flag (-vvv) set?

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/usr/local/nagios/libexec/check_dhcp -vvv
/usr/local/nagios/libexec/check_dhcp -vvv -s <dhcp server ip>

Server address: The IP address of the DHCP server a response to expected from. Leave blank for any server (What does this mean, response to expected from?)

Basically, it is the dhcp server you expect to receive the lease from. The check will fail if that server does not respond. If left blank, the check will succeed if any server responds.

uested IP Address: The IP address expected to be given by the DHCP server. Leave blank for any valid address. (Should i put in a MAC address and preset a reserved IP? How would I make up a MAC address?)

This only pertains to checks that are trying to verify that a specific ip was leased (in cases where static or pre-configured ips are handed our to hosts based on mac address).
Does this help?

[Box293]

From past experience, the problem can be with the local iptables firewall.

In the Nagios XI host, the following iptables commands are required:

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iptables -I INPUT -i eth0 -p udp --dport 68 -j ACCEPT
service iptables save

When you execute the check_dhcp request, the XI server must be on the same physical network segment as the DHCP server.

Code: Select all

./check_dhcp
OK: Received 1 DHCPOFFER(s), max lease time = 600 sec.

If you want to ensure that a specific DHCP server is working, you can target it.

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./check_dhcp -s xxx.xxx.xxx.xxx
OK: Received 1 DHCPOFFER(s), 1 of 1 requested servers responded, max lease time = 600 sec.

Does this help?