CCNA Basic Lessons

01 · Network Fundamentals

OSI model, TCP/IP, Ethernet, IPv4/IPv6, cabling, device roles တွေက CCNA ရဲ့ foundation ပါ။

OSIEthernetIPv4

02 · Cisco IOS Basics

Cisco device တွေကို CLI modes နဲ့ config လုပ်တယ်။ User EXEC, privileged EXEC, global config mode ခွဲသိရမယ်။

enable
configure terminal
hostname R1
show running-config

enableshow

03 · Interfaces

Router/switch interface တွေမှာ IP, description, no shutdown စတာတွေ config လုပ်ရတယ်။

interface g0/0
description LAN
ip address 192.168.1.1 255.255.255.0
no shutdown

interfaceno shut

04 · Switching

Switch က MAC address table ကိုသုံးပြီး frame forwarding လုပ်တယ်။ Broadcast domain, collision domain ကိုနားလည်ဖို့လိုတယ်။

show mac address-table
show interfaces status

MACswitch

05 · VLANs & Trunks

VLAN က LAN ကို logical segment ခွဲတာပါ။ Trunk port က VLAN အများကြီးကို switch-to-switch carry လုပ်တယ်။

vlan 10
name STAFF
interface f0/1
switchport mode access
switchport access vlan 10

VLANtrunk

06 · Routing Basics

Router က network မတူတာတွေကြား packet route လုပ်တယ်။ Static route, default route, dynamic routing idea ကိုနားလည်ရမယ်။

ip route 0.0.0.0 0.0.0.0 192.168.1.254
show ip route

static routegateway

07 · Subnetting Practice

CIDR, subnet mask, network address, broadcast address, usable hosts တွက်တာက CCNA မှာအရေးကြီးဆုံး skill တစ်ခုပါ။

/24 = 255.255.255.0 = 254 hosts
/26 = 255.255.255.192 = 62 hosts

CIDR/26

08 · ACL & NAT

ACL က traffic ကို permit/deny လုပ်တယ်။ NAT က private IP ကို public internet ထွက်နိုင်အောင် translate လုပ်တယ်။

access-list 10 permit 192.168.1.0 0.0.0.255
ip nat inside source list 10 interface g0/0 overload

ACLNAT

09 · Network Services

DHCP, DNS, NTP, SNMP, Syslog စတဲ့ services တွေက network operations အတွက်လိုတယ်။

ip dhcp pool LAN
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 8.8.8.8

DHCPNTP

10 · Wireless Basics

SSID, authentication, encryption, access point, controller concept တွေကိုသိရမယ်။ Enterprise Wi-Fi မှာ segmentation နဲ့ security အရေးကြီးတယ်။

SSIDWPA2WLC

11 · Device Security

SSH enable, local user, enable secret, password encryption, port security, unused ports shutdown စတာတွေက basic hardening ပါ။

enable secret strongpass
username admin secret pass123
ip domain-name lab.local
crypto key generate rsa
line vty 0 4
transport input ssh

SSHhardening

12 · Automation & APIs

Modern network မှာ JSON, REST API, controller-based networking, Python automation concept တွေပါလာတယ်။

GET /restconf/data/interfaces
Content-Type: application/yang-data+json

RESTJSON

Cisco CLI Quick Commands

enable
configure terminal
show ip interface brief
show running-config
show vlan brief
show ip route
show mac address-table
copy running-config startup-config