Hosts file – add an IPv6 address

This builds on adding an IPv4 address - http://msmvps.com/blogs/richardsiddaway/archive/2011/10/24/hosts-file-add-a-record.aspx

function add-IPv6hostfilecontent {            
 [CmdletBinding()]            
 param (            
  [parameter(Mandatory=$true)]            
  [string]$IPAddress,            
              
  [parameter(Mandatory=$true)]            
  [string]$computer            
 )            
 $file = Join-Path -Path $($env:windir) -ChildPath "system32\drivers\etc\hosts"            
 if (-not (Test-Path -Path $file)){            
   Throw "Hosts file not found"            
 }            
 $data = Get-Content -Path $file             
 $data += "$IPAddress  $computer"            
 Set-Content -Value $data -Path $file -Force -Encoding ASCII             
}

 

The only difference is that I’ve removed the regex that checks an IPv4 address.  i haven’t been able to figure out a sensible regex for an IPv6 address. if any one wants to post one as a comment I’ll add it to the function with fill credit

The get-hostfilecontent from http://msmvps.com/blogs/richardsiddaway/archive/2011/10/23/reading-the-hosts-file.aspx works with IPv4 and IPv6 addresses

PS> get-hostfilecontent

Server                                       IPAddress                                  
------                                       ---------                                  
RSLAPTOP01                                   fe80:0000:0000:0000:4547:ee51:7aac:521e    
RSLAPTOP01                                   10.10.54.202

Published Tue, Nov 8 2011 19:21 by RichardSiddaway
Filed under: ,

Comments

# re: Hosts file – add an IPv6 address

Hi Richard,

Here's one version of an IPv6 regex that I intend to publish in a blog post shortly.  I also have a proper IPv4 regex that I'll post for you too :-)

Cheers,

Chris

$IP4='((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})'        # Match a dotted IPv4 address

$Hex='[0-9a-f]{1,4}'    # 1-4 hex characters

# Add ^$ anchors as needed...

$IPv6Regex=@"

(?x)                  # Use extended-mode regex (white-space, comments and newlines in the regex definition are ignored)

^\s*

(

     (( $Hex :){7}      ($Hex                             |:))  |       # 8 Groups of 1-4 Hex characters, or 7 Groups with elided zeroes after 7th group

     (( $Hex :){6}     (:$Hex       |               $IP4  |:))  |       # Elided zeroes after 6th Group of 1-4 Hex characters, or 6 Groups followed by dotted IP4

     (( $Hex :){5}   (((:$Hex){1,2})|             : $IP4  |:))  |       # g:g:g:g:g::g   g:g:g:g:g::g:g   g:g:g:g:g::ip4   g:g:g:g:g::

     (( $Hex :){4}   (((:$Hex){1,3})|((:$Hex)?    : $IP4 )|:))  |       # g:g:g:g::g     g:g:g:g::g:g     g:g:g:g::g:g:g   g:g:g:g::ip4   g:g:g:g::g:ip4   g:g:g:g::

     (( $Hex :){3}   (((:$Hex){1,4})|((:$Hex){0,2}: $IP4 )|:))  |

     (( $Hex :){2}   (((:$Hex){1,5})|((:$Hex){0,3}: $IP4 )|:))  |

     (( $Hex :){1}   (((:$Hex){1,6})|((:$Hex){0,4}: $IP4 )|:))  |

 (:(((: $Hex  ){1,7})|((:$Hex){0,5}               : $IP4 )|:))          # Elided zeroes at front of address:   ::g:g:g:g:g:g:g   ::g    ::g:ip4  etc

)

(%.+)?     # Match optional Zone Index (Scope ID) in Link Local address (there may be multiple link-local addresses (e.g. on different adapters) with different zone indexes)

\s*$

"@

Tuesday, November 08, 2011 2:07 PM by Chris Warwick

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