fix(snmp): accept IPv6 TargetIP on Invoke-SnmpWalk

CHANGELOG.md

@@ -57,6 +57,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `actions/checkout@v7`, and asserts offline dual-stack DrawIO parenting.
 
 ### Fixed
+- **`Invoke-SnmpWalk` accepts IPv6 `TargetIP`.** Validation was IPv4/FQDN-only,
+  so dual-stack SNMP targets failed before the walk. IPv4 and IPv6 literals
+  are parsed with `[System.Net.IPAddress]::TryParse`; hostnames stay accepted.
+  Garbage input still fails with a clear validation error.
 - **`Export-NetBox` IPv6 and unknown reachability.** IPv6 identity addresses
   go in `primary_ip6` (v6-only leaves `primary_ip4` empty). `Reachable=$null`
   no longer maps to `offline`; status is left empty (NetBox has no unknown).

NetDiagram-PS/Public/Invoke-SnmpWalk.ps1

@@ -16,7 +16,7 @@ function Invoke-SnmpWalk {
         not redacted. Treat SNMP v1/v2c community strings as low-secrecy and prefer SNMPv3
         with authentication for anything sensitive.
     .PARAMETER TargetIP
-        IP address or hostname (FQDN) to query. Must not begin with '-'.
+        IPv4 address, IPv6 address, or hostname (FQDN) to query. Must not begin with '-'.
     .PARAMETER Community
         SNMP community string. Must not begin with '-' (argument-injection guard).
     .PARAMETER OID
@@ -27,14 +27,18 @@ function Invoke-SnmpWalk {
         Timeout in seconds (default: 2)
     .EXAMPLE
         Invoke-SnmpWalk -TargetIP '10.66.1.1' -Community 'public'
+    .EXAMPLE
+        Invoke-SnmpWalk -TargetIP '2001:db8::1' -Community 'public'
     #>
     [CmdletBinding()]
     param(
         [Parameter(Mandatory)]
         [ValidateScript({
             if ($_ -match '^-') { throw "TargetIP must not begin with '-'." }
-            if ($_ -notmatch '^(?:\d{1,3}(?:\.\d{1,3}){3}|[A-Za-z0-9]([A-Za-z0-9\-]{0,61}[A-Za-z0-9])?(?:\.[A-Za-z0-9]([A-Za-z0-9\-]{0,61}[A-Za-z0-9])?)*)$') {
-                throw "TargetIP '$_' is not a valid IPv4 address or hostname."
+            $parsed = $null
+            if (-not [System.Net.IPAddress]::TryParse($_, [ref]$parsed) -and
+                $_ -notmatch '^[A-Za-z0-9]([A-Za-z0-9\-]{0,61}[A-Za-z0-9])?(?:\.[A-Za-z0-9]([A-Za-z0-9\-]{0,61}[A-Za-z0-9])?)*$') {
+                throw "TargetIP '$_' is not a valid IP address or hostname."
             }
             $true
         })]

tests/NetDiagram.Tests.ps1

@@ -1419,6 +1419,23 @@ Describe 'Invoke-SnmpWalk parameter validation' {
         { Invoke-SnmpWalk -TargetIP 'switch01.example.com' -Community 'public' } |
             Should -Throw -ExpectedMessage '*snmpwalk not found*'
     }
+
+    It 'Accepts an IPv6 TargetIP without contacting SNMP' {
+        Mock Get-Command { $null } -ModuleName 'NetDiagram-PS' -ParameterFilter { $Name -like 'snmpwalk*' }
+        { Invoke-SnmpWalk -TargetIP '2001:db8::1' -Community 'public' } |
+            Should -Throw -ExpectedMessage '*snmpwalk not found*'
+    }
+
+    It 'Accepts an IPv4 TargetIP without contacting SNMP' {
+        Mock Get-Command { $null } -ModuleName 'NetDiagram-PS' -ParameterFilter { $Name -like 'snmpwalk*' }
+        { Invoke-SnmpWalk -TargetIP '192.0.2.1' -Community 'public' } |
+            Should -Throw -ExpectedMessage '*snmpwalk not found*'
+    }
+
+    It 'Rejects a garbage TargetIP with a clear validation error' {
+        { Invoke-SnmpWalk -TargetIP 'not a valid::address!' -Community 'public' } |
+            Should -Throw -ExpectedMessage '*not a valid IP address or hostname*'
+    }
 }
 
 Describe 'Invoke-PortScan parameter validation' {