# Numbered notes — read in order or jump straight to the topic you need.
* Free resource built from notes while following Jeremy's IT Lab. Feel free to use and share.
> Dynamic Trunking Protocol and VLAN Trunking Protocol — lecture slides.
> STP fundamentals: BPDUs, root bridge election, port roles/states.
> STP convergence, path cost, PVST+, and configuration deep-dive.
> Skip listening/learning on access ports to speed edge-port convergence.
> Protect PortFast edge ports from rogue BPDUs by err-disabling on receipt.
> Why the root bridge matters, how an external switch can hijack it, and how Root Guard protects your STP topology — config, behavior, and recovery.
> Prevent L2 loops when a blocking port stops receiving BPDUs.
> How RSTP converges in seconds instead of 50s — port roles, port states, link types, edge ports, and the proposal/agreement handshake.
> Bundle multiple physical links into one logical interface — Layer 2 and Layer 3 EtherChannel, load balancing, and LACP/PAgP/static configuration.
> IGPs vs EGPs, distance-vector vs link-state, administrative distance and metrics.
> Distance-vector protocols — RIP basics and EIGRP's DUAL algorithm.
> Link-state fundamentals: areas, router IDs, neighbor states, LSAs.
> DR/BDR election, network types, and Hello/Dead timers.
> Cost/metric tuning, authentication, and multi-area OSPF configuration.
> HSRP, VRRP, and GLBP — providing default gateway redundancy on LANs.
> Transport layer protocols — reliable TCP vs connectionless UDP, ports and sockets.
> IPv6 fundamentals: address format, abbreviation rules, and address types.
> IPv6 addressing deep-dive: global unicast, link-local, EUI-64, and SLAAC.
> IPv6 routing, static routes, and neighbor discovery protocol (NDP).
> Numbered/named standard access lists — wildcard masks, placement, and config.
> Filtering by protocol, source/destination, and port — extended ACL syntax.
> Layer 2 discovery protocols — Cisco CDP vs the vendor-neutral LLDP.
> Network Time Protocol — stratum levels, client/server mode, and configuration.
> Name resolution — record types, resolvers, and Cisco DNS client/server config.
> DORA process, DHCP pools, relay agents, and excluded addresses.
> Managers, agents, MIBs, OIDs, traps, and SNMP versions 1/2c/3.
> Severity levels, logging destinations, and timestamps for device logs.
> Secure remote access — RSA keys, domain names, and VTY line config.
> File transfer protocols — IOS image backup, upgrades, and config copies.
> Network Address Translation basics — inside/outside, local/global, static NAT.
> NAT pools, overload (PAT), and port-based translation for many-to-one.
> Classification, marking, queuing, shaping/policing, and voice VLANs.
> Queuing, congestion management/avoidance, shaping vs policing, and trust boundaries.
> CIA triad, threats/vulnerabilities, common attacks, and AAA concepts.
> MAC address limits, sticky learning, and violation modes on access ports.
> Trusted vs untrusted ports, the binding table, and rate limiting DHCP messages.