ccna certification number

ccna certification number.3. Find and load the configuration fileAfter the IOS is loaded successfully, the bootloader searches for the boot configuration file in NVRAM. This file contains the configuration commands and parameters that have been saved. If the boot configuration file is located in NVRAM, the router copies it to RAM as a running configuration file and executes it. If the startup configuration file does not exist in NVRAM, or if the register value is 0x2142 the router prompts whether to enter setup mode. Setup mode consists of a series of interactive questions that prompt the user to enter some basic configuration information. Setup mode is not suitable for complex router configurations and is not typically used by network administrators. setup mode can be exited by using the [CTRL] + [C] key combination.4.1.3 Router Forwarding Packet MechanismsThe router supports the following 3 packet forwarding mechanisms.1. Process SwitchingProcess switching is an earlier version of packet forwarding mechanism, where when a packet arrives at one of the router's interfaces, it is forwarded to the control plane, where the CPU matches the destination address with an entry in its routing table, then determines the outgoing interface and forwards the packet. The router performs this operation for each packet, meaning that each packet must be processed separately by the CPU, even if the source and destination IP addresses of the data stream are the same. This process switching mechanism is inefficient and is rarely used in modern networks.2. Fast SwitchingFast switching, also known as Flow-Based switching, is a common packet forwarding mechanism that uses a fast switching cache to store next-hop information. When a packet arrives at one of the router's interfaces, it is forwarded to the control plane where the CPU will search for a match in the fast switching cache. If no match exists, process switching is applied to the packet and it is forwarded to the sending interface, and the entire data stream information is stored in the fast switching cache at the same time. If another packet to the same destination arrives at the router interface, the next-hop information in the cache can be reused without CPU intervention. However, it is important to note that changes to the IP routing table can invalidate the fast switching cache, and in a network environment where routes are constantly changing, the benefits of fast switching are greatly inhibited.3. Cisco Fast ForwardingCisco Express Forwarding (CEF), also known as Topology-Based