IP routing is how routers pick a path and forward packets between networks. Here is the routing table, next hop, and longest-prefix match in simple terms.
Enabling SSH on a Cisco router or switch takes a hostname, domain name, RSA keys, a local user, and vty line login. Here is the full config plus verification.
Fifty Cisco IOS commands every network admin and CCNA candidate should have in muscle memory, grouped by config, interface, routing, security, and troubleshooting.
SVIs (Switch Virtual Interfaces) are logical VLAN interfaces that enable a Layer 3 switch to route between VLANs and provide management access. Master SVI creation, IP routing enablement, and troubleshooting SVI states.
show interface status tells you more than up/down. Here are five tips for reading it quickly: port status, VLAN, speed/duplex, errdisable, and description use.
Factory resetting a Cisco switch means clearing the config, VLAN database, and sometimes the boot variable. Here are the safe methods and pre-reset prep.
Checking CDP neighbors on a Cisco ASA is a two-command job once CDP is enabled. Here is how to turn it on, read show cdp neighbors, and map your topology.
A Cisco switch gets its management IP on an SVI (usually VLAN 1 or a dedicated mgmt VLAN). Here is the config, the default gateway step, and SSH-readiness.
Get files onto a Cisco router with TFTP, SCP, or USB. Here is how to set up a TFTP server, use copy tftp: flash:, and avoid the common transfer gotchas.
Clear interface counters on a Cisco switch with clear counters to reset a baseline before troubleshooting. Here is how to use it safely and verify errors.
A thorough Cisco port audit hits port status, VLANs, port security, 802.1X, CDP/LLDP, STP role, errors, and unused-port shutdowns. Here are ten repeatable steps.
Enabling HTTP or HTTPS on a Cisco switch takes ip http server, secure-server, AAA, and a trustpoint. Here is the config, the security hardening, and the gotchas.
