Patent ID: 8364843

Claim:
A method comprising: receiving a modified system software at a second route processor, which is in a standby mode, while a first route processor operates in an active mode, where active mode indicates controlling a plurality of line cards for forwarding packets and standby mode indicates not controlling a plurality of line cards for forwarding packets, the first route processor and the second route processor sharing an IP address and a MAC address; updating the second route processor with the modified system software while the first route processor operates in the active mode; synchronizing operation of the second route processor having the modified system software with the first route processor; accessing a minimal context forwarder in a line card, in the plurality of line cards controlled by the first route processor, that is actively forwarding packets, the minimal context forwarder downloaded in the line card being a software code that is derived from the modified system software received at the second route processor, the minimal context forwarder including a subset of the functionality of the modified system software; switching control of routing process from the first route processor to the second route processor with the modified system software, wherein the second route processor with the modified system software operates in the active mode and the first route processor operates in the standby mode; initiating operation of the minimal context forwarder in the line card that received a minimal context forwarder, wherein the minimal context forwarder controls operation of the line card to forward packets, wherein the minimal context forwarder continues forwarding the packets while the minimal context forwarder reloads the line card with the modified system software received from the second route processor; and updating system software code associated with the line card with modified system software while the minimal context forwarder continues forwarding packets.