Cannot set NTP server IP - IBM Flex System



Source

RETAIN tip: H207778

Symptom

There are switch Command Line Interface (CLI) commands that allow the Internet Protocol (IP) address for a Network Time Protocol (NTP) server to be set in an IBM Flex chassis switch.

For example, the Flex System FC3171 8 Gb Storage Area Network (SAN) Pass-thru switch, Option part number 69Y1934, and 69Y1930, uses the '/cfg/sys/ntp/prisrv' command to set the IP address for an external NTP server.

After setting the address, the new setting can be verified using another command ('/cfg/sys/ntp/cur' for the FC3171 switch).

This setting will be wiped out after restarting the switch. It will be replaced by the Internet Protocol version 6 (IPv6) Link Local Address (LLA) assigned to the Chassis Management Module (CMM).

Affected configurations

The system is configured with one or more of the following IBM Options:

  • Flex System EN2092 1 GB Ethernet Scalable Switch, Option part number 49Y4294, any replacement part number (CRU)
  • Flex System EN4093 10 GB Fabric Scalable Switch, Option part number 49Y4270, any replacement part number (CRU)
  • Flex System FC3171 8 GB SAN Pass-thru, Option part number 69Y1934, any replacement part number (CRU)
  • Flex System FC3171 8 GB SAN Switch, Option part number 69Y1930, any replacement part number (CRU)
  • Flex System FC5022 16 Gb SAN Scalable Switch, Option part number 88Y6374, any replacement part number (CRU)
  • Flex System Fabric CN4093 10 GB Converged Scalable Switch, Option part number 00D5823, any replacement part number (CRU)
  • IBM Flex System Fabric EN4093R 10Gb Scalable Switch, Option part number 95Y3309, any EN4093R

This tip is not system specific.

This tip is not software specific.

The system has the symptom described above.

Workaround

The default function of the Chassis Management Module, (CMM), is to act as the NTP time server for all of the chassis components including the Integrated Management Module (IMM) and the chassis I/O modules. Beginning with CMM firmware level 2pet12G, the CMM now provides a way to turn off this feature for switch modules using the GUI interface.

The setting can be found under Chassis Management, I/O Modules, select I/O module, General tab. Turn off the check box for Enable sending NTP information to IOM and click Apply. The CMM will no longer try to set the NTP server address in the switch when this feature is disabled.

Additional information

The switch is working as designed.

Chapter 5 of the 'IBM Flex System FC3171 8 Gb SAN Switch Command Line Interface User's Guide' describes how to set the IP address for a NTP server. The NTP server IP address setting is restricted for all of the Flex chassis switch types.

The User's Guide can be found at the following URL:

http://publib.boulder.ibm.com/infocenter/flexsys/information/topic/com.ibm.acc.networkdevices.doc/88y7936.pdf

The NTP server IP address is set by the CMM during the switch start sequence. It always is set to the IPv6 LLA of the CMM, which acts as the NTP server for all Flex chassis components.

The NTP server IP address will appear to be set after using the CLI command, but will revert back to the CMM IP address during the next switch restart (unless the feature is disabled in the CMM GUI).

The CLI user guides for the other Flex chassis switches also have sections that list a command that can be used to set the NTP server IP address, however, by default, the setting is restricted to the CMM IPv6 LLA for all Flex switches as part of the Flex chassis architecture.

Applicable countries and regions

 


Document id:  MIGR-5092728
Last modified:  2014-04-01
Copyright © 2014 IBM Corporation