📢 This is the study notes of my personal CCNA learning. Most of contents retrived from the Youtube channel Jeremy's IT Lab.
Router Boost Order:
Power on Load Bootstrap POST Load IOS Load startup configuration Generate running configuration
+--------+->-+--------------+->-+----+->-+--------+->-+--------------------------+->-+------------------------------+
ROM ROM flash NVRAM RAM
📎 Table-1 Name Abbrevations
| Abbr. | Names | Purposes | Key-concepts |
|---|---|---|---|
| STP | Spanning Tree Protocol | Loop-free layer2 network | PortFast, BPDU guard/filter, Root/Loop guard |
| DTP | Dynamic Trunking Protocol | Automatically configure switchport states | Trunk/Access ports, native vlan |
| VTP | VLAN Trunking Protocol | Centralized VLANs management | v2 vs v3 |
| CDP | CIsco Discovery Protocol | Exchange device info | Layer 2 |
| NTP | Network Time Protocol | Syncronize time | Defualt stratum 8 |
| NDP | Neighbor Discovering Protocol | Gather info required for IPv6 communication | 5 ICMPv6 packet types |
| UDLD | Unidirectional Link Detection | Help STP to prevent layer2 loops | Unidirectional link |
📎 Table-2 show mac address-table [dynamic | static | vlan <vlan-id> | interface <int-id>]
| Vlan | Mac Address | Type | Ports |
|---|---|---|---|
| ALL | 0100-0ccc-cccc | STATIC | CPU |
| 1 | 0001-1122-aacc | DYNAMIC | Fa0/1 |
Cisco cmds show mac address-table, clear mac address-table dynamic [address <specific-mac> | interface <inter-id>].
Aging is 5 minutes.
📎 Table-3 show arp [vlan <vlan-id>| interface <int-id>]
| Internet Address | Age | Phtsical Address | Type | Interface |
|---|---|---|---|---|
| 169.254.255.255 | - | ff-ff-ff-ff-ff-ff | ARPA | |
| 192.168.1.1 | - | 1122.3344.55aa | ARPA | Vlan1 |
| 192.168.1.101 | 3 | 0001.1122.aacc | ARPA | Vlan1 |
📎 Table-4 Well-know Multicast Addresses
| Purpose | IPv4 Address | IPv6 Address |
|---|---|---|
| All nodes/hosts (like broadcast) | 224.0.0.1 | FF02::1 |
| All routers | 224.0.0.2 | FF02::2 |
| All OSPF routers | 224.0.0.5 | FF02::5 |
| All OSPF DR/BDRs | 224.0.0.6 | FF02::6 |
| All RIP routers | 224.0.0.9 | FF02::9 |
| All EIGRP routers | 224.0.0.10 | FF02::A |
📎 Table-5 Routing Protocols
| Abbr. | Names | Based on | Encap | Neighborship |
|---|---|---|---|---|
| OSPF | Open Shortest Path First | Link state | IP 89 | Dynamic dicover - Hello |
| EIGRP | Enhanced Interior Gateway Routing Protocol | Advanced Distance vector | IP 88 | |
| RIP | Routing Information Protocol | Distance vector | UDP 520 | |
| BGP | Border Gateway Protocol | Path vector | TCP 179 | Static config explicitly |
| IS-IS | Intermediate System - Intermediate System | Link state | L2 |
📎 Table-6 Network Automation Tools
| Name | Client-SRV | Op-Model | Protocol | Port | By-Lang | Use-Lang | Key Components |
|---|---|---|---|---|---|---|---|
| Ansible | agentless | push model | SSH | 22 | Python | YAML | Control Node: Inventory, Template, Variable, Playbook |
| Puppet | agent-based; agentless | pull model | HTTP(s) | 8140 | Ruby | Declarative lang | Puppet Master: Manifest , Templates |
| Chef | agent-based | pull model | HTTP(s) | 10002 | Ruby | Resources, Recipes, Cookbooks, Run-list |