Spectrum to monitor Cisco DHCP pool exhausted

Products

• CA Spectrum

Issue/Introduction

We have a requirement where DHCP related traps that are being sent by devices need to be monitored. The requirement is to monitor the DHCP IP uses when it reaches 80%. As per the team, they are sending trap: snmp-server enable traps dhcp.

Will this trap be enabled to alert for DHCP exhaust issues.?

 

Environment

Release : 10.4.1

Component : Spectrum Certification

Resolution

Out Of the Box (OOB) Spectrum does not have the CISCO-IETF-DHCP-SERVER-MIB included. But you can download it from your Vendor and easily import/compile it in Spectrum via MIB Tools utility.

In the following screenshot, you can see how to import/compile the CISCO-IETF-DHCP-SERVER-MIB in the MIB Tools:

Then you can map one or more traps in MIB Tools, you can also choose an Alarm Severity. Note that not all traps should raise alarms. The cDhcpv4ServerFreeAddressHigh would clear the alarm generated by cDhcpv4ServerFreeAddressLow trap

You can follow this KB to understand the step to import/compile and then map the trap you are interested in:

https://knowledge.broadcom.com/external/article?articleId=137203

Also, engage your device's administrator to confirm the trap the device will send when the DHCP pool is near to exhaust. In my research I found the following:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/15-s/dhcp-15-s-book/dhcp-serv-mib.html

Table 8

cDhcpv4ServerNotificationsGroup and Descriptions

Name	Description
cDhcpv4ServerFreeAddressLow	This notification signifies that the number of available IP addresses for a DHCP address pool has fallen below the defined low threshold. This notification corresponds to the snmp-server enable traps dhcp global configuration command.
cDhcpv4ServerFreeAddressHigh	This notification signifies that the number of available IP addresses for a DHCP address pool has risen above the defined high threshold. This notification corresponds to the snmp-server enable traps dhcp global configuration command.
cDhcpv4ServerStartTime	This notification signifies that the server has started. This notification corresponds to the service dhcp and snmp-server enable traps dhcp timeglobal configuration commands.
cDhcpv4ServerStopTime	This notification signifies that the server has stopped normally. This notification corresponds to the no service dhcp and snmp-server enable traps dhcp timeglobal configuration commands.
cDhcpv4ServerDuplicateAddress	This notification signifies that a duplicate IP address has been detected. This notification corresponds to the snmp-server enable traps dhcp duplicateglobal configuration command.