Speed up powershell command when using calculated properties - powershell

Question

So I wanted to get a powershell command to list the firewall rules and ports, and I had to basically use 2 commands: Get-NetFirewallRule and Get-NetFirewallPortFilter.
So I basically came up with this:
Get-NetFirewallPortFilter | where-object {$_.LocalPort -cmatch '[0-9]+'}|select-object -Property #{n='Name';e={($_ | Get-NetFirewallRule).Name}}, #{n='Description';e={($_ | Get-NetFirewallRule).description}}, Protocol, LocalPort, RemotePort, #{n='Direction';e={($_|Get-NetFirewallRule).Direction}}
I went with Get-NetFirewallPortFilter first because I wanted to only get numerical ports (so I didn't want to get 'Any' as a result).
Problem is, the more calculated properties I have, the slower this runs. It generates like 3 lines a second, which IMO is very slow.
I timed the command to see how long it takes (did an Out-GridView to also see the output, I don't think it adds THAT much more to the time, it seems to generate just as many lines a second):
PS C:\> measure-command { Get-NetFirewallPortFilter | where-object {$_.LocalPort -cmatch '[0-9]+'}|select-object -Property #{n='Name';e={($_ | Get-NetFirewallRule).Name}}, #{n='Description';e={($_ | Get-NetFirewallRule).description}}, Protocol, LocalPort, RemotePort, #{n='Direction';e={($_|Get-NetFirewallRule).Direction}} |out-gridview }
Days : 0
Hours : 0
Minutes : 1
Seconds : 59
Milliseconds : 143
Ticks : 1191434968
TotalDays : 0.00137897565740741
TotalHours : 0.0330954157777778
TotalMinutes : 1.98572494666667
TotalSeconds : 119.1434968
TotalMilliseconds : 119143.4968
It output 358 lines in ~119 seconds.
Are there any optimizations I can run to make this run faster?

Answer 1

You are using Get-NetFirewallRule multiple times in your code, where you could do this only once per PortFilter:
Get-NetFirewallPortFilter | Where-Object {$_.LocalPort -match '[0-9]+'} | ForEach-Object {
$rule = $_ | Get-NetFirewallRule
$_ | Select-Object #{Name = 'Name'; Expression = {$rule.Name}},
#{Name = 'Description'; Expression = {$rule.Description}},
Protocol, LocalPort, RemotePort,
#{Name = 'Direction'; Expression = {$rule.Direction}}
} | Out-GridView
It might be just a tad faster if you take out the ForEach-Object and use a foreach() instead:
$portFilters = Get-NetFirewallPortFilter | Where-Object {$_.LocalPort -match '[0-9]+'}
$result = foreach ($filter in $portFilters) {
$rule = $filter | Get-NetFirewallRule
$filter | Select-Object #{Name = 'Name'; Expression = {$rule.Name}},
#{Name = 'Description'; Expression = {$rule.Description}},
Protocol, LocalPort, RemotePort,
#{Name = 'Direction'; Expression = {$rule.Direction}}
}
$result | Out-GridView

Answer 2

Filtering left is always fastest, with get-netfirewallportfilter first. This takes about 18 seconds. I had trouble using -pipelinevariable (or -pv) with get-netfirewallportfilter. Powershell commands manipulate objects vs linux commands that manipulate text.
EDIT: Piping to get-netfirewallrule behaves oddly, like all the objects would be processed in one shot. I put it inside a foreach-object. I changed name to displayname and put description last.
# not work
Get-NetFirewallPortFilter -pipelinevariable port
Get-NetFirewallPortFilter : Cannot retrieve the dynamic parameters for the cmdlet. Object reference not set to an
instance of an object.
At line:1 char:1
+ Get-NetFirewallPortFilter -pipelinevariable port
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Get-NetFirewallPortFilter], ParameterBindingException
+ FullyQualifiedErrorId : GetDynamicParametersException,Get-NetFirewallPortFilter
Get-NetFirewallPortFilter |
where localPort -match \d -pipelinevariable port |
% { $_ | Get-NetFirewallRule } | select displayname,
#{n='Protocol'; e={$port.protocol}},
#{n='Localport'; e={$port.localport}},
#{n='Remoteport';e={$port.remoteport}},
direction, description | ft
DisplayName Protocol Localport Remoteport Direction description
----------- -------- --------- ---------- --------- -----------
SNMP Trap Service (UDP In) UDP 162 Any Inbound Inbound rule for the SNMP Trap Service to allow SNMP traps. [UDP 162]
SNMP Trap Service (UDP In) UDP 162 Any Inbound Inbound rule for the SNMP Trap Service to allow SNMP traps. [UDP 162]
Delivery Optimization (TCP-In) TCP 7680 Any Inbound Inbound rule to allow Delivery Optimization to connect to remote endpoints