Network Fundamentals Foundational ~5 min

Configure and save — running-config vs. startup-config

The rookie mistake: making real config changes and then losing them on the next power cycle because they were only in the running-config, not the startup-config. Rename the router to CORE-1, bring up Gi0/0 with an address and a description, then persist everything to NVRAM so it survives a reload.

Topology

Router

Objectives

○Hostname set to CORE-1
○Gi0/0 description = UPLINK-TO-CORE
○Gi0/0 IP = 10.0.0.1/24
○Gi0/0 is up (no shutdown)
○Running config saved to startup (NVRAM)

Hints

Hint — two equivalent save commands

Both work: copy running-config startup-config (modern) or write memory (legacy shorthand, still supported).

Hint — full sequence

enable
configure terminal
 hostname CORE-1
 interface Gi0/0
  description UPLINK-TO-CORE
  ip address 10.0.0.1 255.255.255.0
  no shutdown
  exit
 end
copy running-config startup-config

Verify with

show ip interface brief (interface state), show running-config (what's in RAM), show startup-config (what NVRAM will restore on next boot).

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Set hostname and enable secret

Network Fundamentals · ~3 min

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Assign an IP to a router interface

Network Fundamentals · ~4 min