Windows Networking

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Cấu hình Network Interface

# Xem network adapters
Get-NetAdapter                              # tất cả adapter
Get-NetAdapter -Name "Ethernet"            # adapter cụ thể
Get-NetIPAddress                           # tất cả IP
Get-NetIPAddress -AddressFamily IPv4       # chỉ IPv4
Get-NetIPConfiguration                     # IP, Gateway, DNS đầy đủ

# Cấu hình IP tĩnh
New-NetIPAddress -InterfaceAlias "Ethernet" `
                 -IPAddress "192.168.1.100" `
                 -PrefixLength 24 `
                 -DefaultGateway "192.168.1.1"

# Đổi DNS
Set-DnsClientServerAddress -InterfaceAlias "Ethernet" `
    -ServerAddresses "8.8.8.8","8.8.4.4"

# Về DHCP
Remove-NetIPAddress -InterfaceAlias "Ethernet" -Confirm:$false
Remove-NetRoute -InterfaceAlias "Ethernet" -Confirm:$false
Set-NetIPInterface -InterfaceAlias "Ethernet" -Dhcp Enabled
Set-DnsClientServerAddress -InterfaceAlias "Ethernet" -ResetServerAddresses

# Bật/tắt adapter
Disable-NetAdapter -Name "Ethernet" -Confirm:$false
Enable-NetAdapter -Name "Ethernet"

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Lệnh Network cơ bản (CMD)

:: Xem IP
ipconfig                    :: tóm tắt
ipconfig /all               :: chi tiết (MAC, DNS, DHCP...)
ipconfig /flushdns          :: xoá DNS cache
ipconfig /release           :: trả IP về DHCP
ipconfig /renew             :: xin IP mới từ DHCP

:: Routing
route print                 :: bảng routing
route add 10.0.0.0 mask 255.0.0.0 192.168.1.1      :: thêm route
route delete 10.0.0.0                               :: xoá route
route add 10.0.0.0 mask 255.0.0.0 192.168.1.1 -p   :: persistent

:: Test kết nối
ping google.com
ping -n 10 192.168.1.1      :: 10 lần
tracert google.com          :: trace route (= traceroute trên Linux)
pathping google.com         :: kết hợp ping + tracert

:: DNS
nslookup google.com
nslookup -type=MX company.com
nslookup google.com 8.8.8.8     :: dùng DNS server cụ thể

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netsh — Network Shell

netsh là công cụ CLI mạnh mẽ để cấu hình mạng trên Windows:

:: Xem interface
netsh interface show interface
netsh interface ipv4 show addresses

:: Cấu hình IP tĩnh
netsh interface ipv4 set address "Ethernet" static 192.168.1.100 255.255.255.0 192.168.1.1

:: DNS
netsh interface ipv4 set dns "Ethernet" static 8.8.8.8
netsh interface ipv4 add dns "Ethernet" 8.8.4.4 index=2

:: Xem connections (netstat)
netstat -an                 :: tất cả connections
netstat -anob               :: kèm process (cần admin)
netstat -anob | findstr :80 :: ai dùng port 80?
netstat -s                  :: statistics

:: Firewall
netsh advfirewall show allprofiles
netsh advfirewall firewall show rule name=all
netsh advfirewall firewall add rule name="Allow HTTP" dir=in action=allow protocol=tcp localport=80
netsh advfirewall firewall delete rule name="Allow HTTP"

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Windows Firewall (PowerShell)

# Xem profiles (Domain, Private, Public)
Get-NetFirewallProfile

# Bật/tắt Firewall
Set-NetFirewallProfile -Profile Domain,Private,Public -Enabled True

# Xem rules
Get-NetFirewallRule | Where-Object {$_.Enabled -eq "True"} | Select-Object DisplayName, Direction, Action

# Thêm rule
New-NetFirewallRule -DisplayName "Allow HTTPS Inbound" `
                    -Direction Inbound `
                    -Protocol TCP `
                    -LocalPort 443 `
                    -Action Allow `
                    -Profile Any

# Giới hạn theo IP
New-NetFirewallRule -DisplayName "Allow SSH from Office" `
                    -Direction Inbound `
                    -Protocol TCP `
                    -LocalPort 22 `
                    -RemoteAddress "192.168.1.0/24" `
                    -Action Allow

# Xoá rule
Remove-NetFirewallRule -DisplayName "Allow HTTPS Inbound"

# Tắt/bật rule
Disable-NetFirewallRule -DisplayName "Allow HTTPS Inbound"
Enable-NetFirewallRule -DisplayName "Allow HTTPS Inbound"

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DNS Troubleshoot trên Windows

# Tra DNS
Resolve-DnsName google.com                      # nslookup kiểu PowerShell
Resolve-DnsName google.com -Type MX            # MX record
Resolve-DnsName google.com -Server 8.8.8.8    # dùng DNS server cụ thể
Resolve-DnsName 142.250.x.x                    # reverse lookup

# Xoá cache
Clear-DnsClientCache                            # ipconfig /flushdns
Get-DnsClientCache                              # xem cache hiện tại

# Test kết nối
Test-NetConnection google.com                   # ping + port test
Test-NetConnection google.com -Port 443         # test HTTPS
Test-NetConnection 192.168.1.10 -Port 3306 -InformationLevel Detailed

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Network Troubleshoot Commands

# Xem port đang listen
Get-NetTCPConnection -State Listen | Select-Object LocalPort, State, OwningProcess |
    Sort-Object LocalPort

# Kết hợp với process name
Get-NetTCPConnection -State Listen | ForEach-Object {
    $proc = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue
    [PSCustomObject]@{
        Port    = $_.LocalPort
        Process = $proc.Name
        PID     = $_.OwningProcess
    }
} | Sort-Object Port

# Bandwidth usage (cần Network Monitor hoặc Wireshark)
# Hoặc dùng Performance Counter
Get-Counter "\Network Interface(*)\Bytes Total/sec" -SampleInterval 2 -MaxSamples 5

# Xem ARP table
arp -a                          # CMD
Get-NetNeighbor                 # PowerShell

# SMB connections (Windows file sharing)
Get-SmbConnection               # connection đang mở
Get-SmbSession                  # session đến server này
Get-SmbShare                    # share đang publish

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Network Shares (SMB)

# Tạo share
New-SmbShare -Name "Deploy" `
             -Path "C:\deployments" `
             -Description "Deployment files" `
             -FullAccess "DOMAIN\DevOps-Team" `
             -ReadAccess "DOMAIN\Developers"

# Xem shares
Get-SmbShare
Get-SmbShareAccess -Name "Deploy"

# Xoá share
Remove-SmbShare -Name "Deploy" -Confirm:$false

# Map network drive từ client
New-PSDrive -Name Z -PSProvider FileSystem `
    -Root \\server\Deploy -Credential (Get-Credential) -Persist