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Cisco Bug: CSCur72161 - CUCM GUI: Subnet IP address is not validated in DHCP Configuration page

Last Modified

Oct 27, 2017

Products (8)

  • Cisco Unified Communications Manager (CallManager)
  • Cisco Intercompany Media Engine
  • Cisco Business Edition 5000 Version 9.1
  • Cisco Unity Connection Version 9.1
  • Cisco Unified Communications Manager Version 9.1
  • Cisco Unified Communications Manager Version 10.0
  • Cisco Business Edition 6000 Version 9.1
  • Cisco Unified Communications Manager Session Management Edition

Known Affected Releases

10.0(1) 10.5(1.10000.7) 9.1(2)

Description (partial)

The GUI of CUCM does not have any validation mechanism to check if the subnet address is valid as per the subnet mask given in the "DHCP Subnet Configuration" page.

Eg. For a subnet mask of, the valid subnet ip addresses are :

However, the GUI page accepts invalid subnet masks like etc . This configuration finally gets inserted into dhcpd.conf file and prevents the dhcpd daemon from getting started on the next reboot or restart of the DHCP monitor service. 

Problem Symptoms can include: 
1)IP Phones loosing registration indicating DHCP lease expiry
2)CiscoSyslog contains alerts indicating dhcpd service is down.

The issue happens when invalid Subnet IP address is entered by the administrator while configuring the DHCP Subet details.
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Bug Details Include

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