186 BigIron RX Installation Guide53-1001811-01Upgrading the BigIron RX Series software7Using this feature, you can upgrade the Multi-Service IronWare software without a loss of service ordisruption in the following supported functions and protocols:• All ports and links remain operational• TOS-based QoS• Layer-2 Switching• Layer-2 Protocols:• MRP• STP• VSRP• RSTP• MSTPConsiderations when using the featureConsider the following when using this feature:• You must have both active and standby management modules installed to use this feature.• To avoid any disruptions of Layer-3 traffic to OSPF or BGP routes, the router must be configuredwith OSPF Graceful Restart and BGP Graceful Restart features. In addition, the device’s OSFPneighbors must have OSPF Graceful Restart Helper enabled.• The total time it takes for the hitless upgrade process to finish varies between approximately 1and 10 minutes. This depends on the size of the MAC table, the number of OSPF and BGPneighbors and the size of the routing table. Router configuration is unavailable during theentire hitless upgrade process. The message "---SW Upgrade In Progress - Please Wait---" isprinted at the console when configuration is attempted. Operational command of the router isallowed during the upgrade process.• The active management module changes from the initial active management module to thestandby management module during the hitless upgrade process. This makes it necessary tohave a connection to the console interface on both management modules.• Upon being reset, the management and interface module CPUs are unable to send and receiveany packets. Once the management and interface modules are up and running, their CPUs areable to send and receive packets, even before the hitless upgrade process is complete.• Router configuration is not allowed to be changed during the entire hitless upgrade process.• System-max parameter changes or other configuration changes that require a system reloadsuch as "cam-mode" and cam-profile" changes do not take effect upon hitless upgrade.• FPGA images cannot be upgraded using the hitless upgrade process.• This feature cannot be used to downgrade an image to an older major version than the versionthat the device is currently running.• If there are protocol dependencies between neighboring nodes, it is recommended that onlyeach node is upgraded: one node at a time.• After hitless upgrade, the BigIron RX router will still have the same running configuration as itdoes before the upgrade. A configuration that is not saved before hitless reload is not removedand the existing startup configuration does not take effect. This behavior is the same asdisplayed by the management module switchover feature.
