[Source] Hostname To IP

[AceInfinity]

You should use MessageBox.Show instead of MsgBox euverve

Also maybe a With statement?

Code:

With postReq
    .Method = "POST"
    .KeepAlive = True
    .ContentType = "application/x-www-form-urlencoded"
    .Referer = host
    .UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; ru; rv:1.9.2.3) Gecko/20100401 Firefox/4.0 (.NET CLR 3.5.30729)"
    .ContentLength = byteData.Length
End With

Otherwise not bad