3Com 4005 Installation And Maintenance Manual

Also see for 4005: Key Information Guide Datasheet

Contents

3Com 4005 Installation And Maintenance Manual Manual pdf 48 page image

48 CHAPTER 7: SWITCH FABRIC M ANAGEMENT MODULES AND I NTERFACE M ODULESInstallation If you install two Switch Fabric Management Modules (in slot M1 and M2), yoursystem has redundancy in both management and system controller functions.When you power on or reboot the system with two SFMMs installed, the modulein slot M1 becomes the primary SFMM and the module in slot M2 becomes thesecondary SFMM. However, if you install an SFMM while the system is poweredon, the first module installed becomes the primary SFMM and second moduleinstalled becomes the secondary SFMM.The Primary LED will light up on the module your system has assigned as thePrimary SFMM.The RelationshipBetween TwoManagement ModulesThe system categorizes the two SFMMs as primary and secondary managemententities. The secondary module operates in hot standby mode, which means that itis constantly kept informed about the dynamic state of the management activitiesthat are occurring on the primary SFMM.The system treats both SFMMs as a single logical device. The primary SFMM andthe secondary SFMM become synchronized after redundancy is established. Whenany configuration or non-volatile data is modified on the primary SFMM, the datais automatically modified on the secondary SFMM. Thus, if the primary SFMM failsfor any reason, the secondary SFMM immediately takes over all primary functions.The Failover Process If you remove (deinstall) the primary SFMM or if the module fails in some way, thefollowing process occurs automatically:1 The system initiates the fail-over mechanism (after, for example, the primarymodule fails or is removed).2 The system reboots and the secondary SFMM becomes the primary SFMM.Because it learned all the configuration settings from the primary SFMM, itcontinues to provide all the management functions.3 If you remove a failed SFMM that used to be primary and install a new SFMM inthat slot, the new module remains secondary and starts duplicating allconfiguration information.If, after the failover occurs, the failed SFMM recovers to a normal operatingcondition, it will remain in the secondary state. The failover mechanism isnon-revertive. Even if the problem that caused the failover is resolved, the failoverprocess does not switch the primary state back to the original primary SFMMunless the system is rebooted.Connectivity Rules The following connectivity rules apply after you establish SFMM redundancy: You cannot access the secondary SFMM through its console port. Consolemanagement is only available through the primary SFMM. You cannot Telnet to the secondary SFMM from an external source becauseboth the primary SFMM and the secondary SFMM share the same IP addressfor the Switch. Therefore, when you attempt to Telnet to the shared IP address,you always access the primary SFMM.