–A–

–B–

–C–

–D–

DHCP servers, list for this domain

Get-DhcpServerInDC

–E–

–F–

firewall ports - see ports, firewall

firewall, configure for domains and trusts

are ports 53, 135, 445 & 3268 enabled?

Get-NetFirewallPortFilter -PolicyStore ActiveStore `
    | ? {($_.LocalPort -eq '53') -or ($_.LocalPort -eq '135') -or ($_.LocalPort -eq '389') -or ($_.LocalPort -eq '445') -or ($_.LocalPort -eq '3268 ')} `
    | Sort-Object LocalPort, Protocol | Format-Table -Property *

or more simply:

Get-NetFirewallPortFilter -PolicyStore ActiveStore `
    | ? {($_.LocalPort -eq '53') -or ($_.LocalPort -eq '135') -or ($_.LocalPort -eq '389') -or ($_.LocalPort -eq '445') -or ($_.LocalPort -eq '3268')} `
    | Sort-Object LocalPort, Protocol | Format-Table Protocol, LocalPort, InstanceID

But not sure this is the right approach. This seems more centered on services rather than ports...

–G–

–H–

–I–

–J–

–K–

–L–

–M–

–N–

–O–

–P–

ports, established (used)

Get-NetTCPConnection -State Established

seems to sort descending by LocalPort

ports, firewall

Get-NetFirewallPortFilter -PolicyStore ActiveStore | ? {$_.LocalPort -ne 'any'} | Sort-Object LocalPort, Protocol | Format-Table -Property *

–Q–

–R–

–S–

–T–

–U–

–W–

–X–

–Y–

–Z–