Last year I needed to figure out a way to get the following information with Python: get the route table, capture the data from pinging a series of IPs, run tracert and get information about the NIC(s) installed. This all needed to be done on a Windows machine as it was part of a diagnostics script to try to figure out why the machine (usually a laptop) wouldn’t connect to our VPN. I ended up creating a wxPython GUI to make it easy for the user to run, but these scripts will work just fine without wx. Let’s see what they look like!
The Main Script
To start with, we’ll look at the entire script and then go over each important piece. If you’d like to use the code below, you will need wxPython and the PyWin32 package.
import os
import subprocess
import sys
import time
import win32com.client
import win32net
import wx
filename = r"C:\logs\nic-diag.log"
class RedirectText:
def __init__(self,aWxTextCtrl):
self.out=aWxTextCtrl
if not os.path.exists(r"C:\logs"):
os.mkdir(r"C:\logs")
self.filename = open(filename, "w")
def write(self,string):
self.out.WriteText(string)
if self.filename.closed:
pass
else:
self.filename.write(string)
class MyForm(wx.Frame):
#----------------------------------------------------------------------
def __init__(self):
wx.Frame.__init__(self, None, wx.ID_ANY, "Diagnostic Tool")
# Add a panel so it looks the correct on all platforms
panel = wx.Panel(self, wx.ID_ANY)
log = wx.TextCtrl(panel, wx.ID_ANY, size=(300,100),
style = wx.TE_MULTILINE|wx.TE_READONLY|wx.HSCROLL)
# log.Disable()
btn = wx.Button(panel, wx.ID_ANY, 'Run Diagnostics')
self.Bind(wx.EVT_BUTTON, self.onRun, btn)
# Add widgets to a sizer
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(log, 1, wx.ALL|wx.EXPAND, 5)
sizer.Add(btn, 0, wx.ALL|wx.CENTER, 5)
panel.SetSizer(sizer)
# redirect text here
self.redir=RedirectText(log)
sys.stdout=self.redir
#----------------------------------------------------------------------
def runDiagnostics(self):
"""
Run some diagnostics to get the machine name, ip address, mac,
gateway, DNS, route tables, etc
"""
# create the route table:
# based on the following list comp from http://win32com.goermezer.de/content/view/220/284/
# route_table = [elem.strip().split() for elem in os.popen("route print").read().split("Metric\n")[1].split("\n") if re.match("^[0-9]", elem.strip())]
route_table = []
proc = subprocess.Popen("route print", shell=True,
stdout=subprocess.PIPE)
while True:
line = proc.stdout.readline()
route_table.append(line.strip().split())
if not line: break
proc.wait()
print "Log Created at %s" % time.ctime()
print "----------------------------------------------------------------------------------------------"
info = win32net.NetWkstaGetInfo(None, 102)
self.compname = info["computername"]
print "Computer name: %s\n" % self.compname
print "----------------------------------------------------------------------------------------------"
print "Route Table:"
print "%20s\t %15s\t %15s\t %15s\t %s" % ("Network Destination", "Netmask",
"Gateway", "Interface", "Metric")
for route in route_table:
if len(route) == 5:
dst, mask, gateway, interface, metric = route
print "%20s\t %15s\t %15s\t %15s\t %s" % (dst, mask, gateway, interface, metric)
print "----------------------------------------------------------------------------------------------\n"
ips = ["65.55.17.26", "67.205.46.185", "67.195.160.76"]
for ip in ips:
self.pingIP(ip)
print
self.tracertIP(ip)
print "\n----------------------------------------------------------"
self.getNICInfo()
print "############ END OF LOG ############"
#----------------------------------------------------------------------
def pingIP(self, ip):
proc = subprocess.Popen("ping %s" % ip, shell=True,
stdout=subprocess.PIPE)
print
while True:
line = proc.stdout.readline()
wx.Yield()
if line.strip() == "":
pass
else:
print line.strip()
if not line: break
proc.wait()
#----------------------------------------------------------------------
def tracertIP(self, ip):
proc = subprocess.Popen("tracert -d %s" % ip, shell=True,
stdout=subprocess.PIPE)
print
while True:
line = proc.stdout.readline()
wx.Yield()
if line.strip() == "":
pass
else:
print line.strip()
if not line: break
proc.wait()
#----------------------------------------------------------------------
def getNICInfo(self):
"""
http://www.microsoft.com/technet/scriptcenter/scripts/python/pyindex.mspx?mfr=true
"""
print "\nInterface information:\n"
strComputer = "."
objWMIService = win32com.client.Dispatch("WbemScripting.SWbemLocator")
objSWbemServices = objWMIService.ConnectServer(strComputer,"root\cimv2")
colItems = objSWbemServices.ExecQuery("Select * from Win32_NetworkAdapterConfiguration")
numOfNics = len(colItems)
count = 1
for objItem in colItems:
# if the IP interface is enabled, grab its info
print "***Interface %s of %s***" % (count, numOfNics)
if objItem.IPEnabled == True:
print "Arp Always Source Route: ", objItem.ArpAlwaysSourceRoute
print "Arp Use EtherSNAP: ", objItem.ArpUseEtherSNAP
print "Caption: ", objItem.Caption
print "Database Path: ", objItem.DatabasePath
print "Dead GW Detect Enabled: ", objItem.DeadGWDetectEnabled
z = objItem.DefaultIPGateway
if z is None:
a = 1
else:
for x in z:
print "Default IP Gateway: ", x
print "Default TOS: ", objItem.DefaultTOS
print "Default TTL: ", objItem.DefaultTTL
print "Description: ", objItem.Description
print "DHCP Enabled: ", objItem.DHCPEnabled
print "DHCP Lease Expires: ", objItem.DHCPLeaseExpires
print "DHCP Lease Obtained: ", objItem.DHCPLeaseObtained
print "DHCP Server: ", objItem.DHCPServer
print "DNS Domain: ", objItem.DNSDomain
z = objItem.DNSDomainSuffixSearchOrder
if z is None:
a = 1
else:
for x in z:
print "DNS Domain Suffix Search Order: ", x
print "DNS Enabled For WINS Resolution: ", objItem.DNSEnabledForWINSResolution
print "DNS Host Name: ", objItem.DNSHostName
z = objItem.DNSServerSearchOrder
if z is None:
a = 1
else:
for x in z:
print "DNS Server Search Order: ", x
print "Domain DNS Registration Enabled: ", objItem.DomainDNSRegistrationEnabled
print "Forward Buffer Memory: ", objItem.ForwardBufferMemory
print "Full DNS Registration Enabled: ", objItem.FullDNSRegistrationEnabled
z = objItem.GatewayCostMetric
if z is None:
a = 1
else:
for x in z:
print "Gateway Cost Metric: ", x
print "IGMP Level: ", objItem.IGMPLevel
print "Index: ", objItem.Index
z = objItem.IPAddress
if z is None:
a = 1
else:
for x in z:
print "IP Address: ", x
print "IP Connection Metric: ", objItem.IPConnectionMetric
print "IP Enabled: ", objItem.IPEnabled
print "IP Filter Security Enabled: ", objItem.IPFilterSecurityEnabled
print "IP Port Security Enabled: ", objItem.IPPortSecurityEnabled
z = objItem.IPSecPermitIPProtocols
if z is None:
a = 1
else:
for x in z:
print "IP Sec Permit IP Protocols: ", x
z = objItem.IPSecPermitTCPPorts
if z is None:
a = 1
else:
for x in z:
print "IP Sec Permit TCP Ports: ", x
z = objItem.IPSecPermitUDPPorts
if z is None:
a = 1
else:
for x in z:
print "IPSec Permit UDP Ports: ", x
z = objItem.IPSubnet
if z is None:
a = 1
else:
for x in z:
print "IP Subnet: ", x
print "IP Use Zero Broadcast: ", objItem.IPUseZeroBroadcast
print "IPX Address: ", objItem.IPXAddress
print "IPX Enabled: ", objItem.IPXEnabled
z = objItem.IPXFrameType
if z is None:
a = 1
else:
for x in z:
print "IPX Frame Type: ", x
print "IPX Media Type: ", objItem.IPXMediaType
z = objItem.IPXNetworkNumber
if z is None:
a = 1
else:
for x in z:
print "IPX Network Number: ", x
print "IPX Virtual Net Number: ", objItem.IPXVirtualNetNumber
print "Keep Alive Interval: ", objItem.KeepAliveInterval
print "Keep Alive Time: ", objItem.KeepAliveTime
print "MAC Address: ", objItem.MACAddress
print "MTU: ", objItem.MTU
print "Num Forward Packets: ", objItem.NumForwardPackets
print "PMTUBH Detect Enabled: ", objItem.PMTUBHDetectEnabled
print "PMTU Discovery Enabled: ", objItem.PMTUDiscoveryEnabled
print "Service Name: ", objItem.ServiceName
print "Setting ID: ", objItem.SettingID
print "Tcpip Netbios Options: ", objItem.TcpipNetbiosOptions
print "Tcp Max Connect Retransmissions: ", objItem.TcpMaxConnectRetransmissions
print "Tcp Max Data Retransmissions: ", objItem.TcpMaxDataRetransmissions
print "Tcp Num Connections: ", objItem.TcpNumConnections
print "Tcp Use RFC1122 Urgent Pointer: ", objItem.TcpUseRFC1122UrgentPointer
print "Tcp Window Size: ", objItem.TcpWindowSize
print "WINS Enable LMHosts Lookup: ", objItem.WINSEnableLMHostsLookup
print "WINS Host Lookup File: ", objItem.WINSHostLookupFile
print "WINS Primary Server: ", objItem.WINSPrimaryServer
print "WINS Scope ID: ", objItem.WINSScopeID
print "WINS Secondary Server: ", objItem.WINSSecondaryServer
print "-------------------------------------------------------\n"
else:
print "Interface is disabled!\n"
count += 1
#----------------------------------------------------------------------
def onRun(self, event):
self.runDiagnostics()
self.redir.filename.close()
# Restore stdout to normal
sys.stdout = sys.__stdout__
#----------------------------------------------------------------------
# Run the program
if __name__ == "__main__":
app = wx.PySimpleApp()
frame = MyForm().Show()
app.MainLoop()
As with most Python programs, this one starts out with various imports. Next we create a a simple class (RedirectText) that we will use to help us redirect stdout to a wx.TextCtrl and a log file. This works by passing in an instance of wx.TextCtrl and then setting “sys.stdout” to point to it (see the __init__ method in the MyForm class). Following the RedirectText class, we have the MyForm class which is where we create out wxPython GUI. There’s actually not much to the GUI itself. Just a multi-line text control and a button on a panel, but that’s all we need. The rest of the class is made up of methods that gather all our required information and log it to the screen and to a file.
Let’s take a look at those methods now! Note that these methods are called from the runDiagnostics method which is launched from the onRun button event handler.
Getting the Route Table (AKA: IP Routes)
When I looked into how to do this, I found the following script on another blog:
import os, re
route_table = [elem.strip().split() for elem in os.popen("route print").read().split("Metric\n")[1].split("\n") if re.match("^[0-9]", elem.strip())]
I found that rather hard to follow, so I re-wrote it (or found another example and forgot to make a note of it) like this:
route_table = []
proc = subprocess.Popen("route print", shell=True,
stdout=subprocess.PIPE)
while True:
line = proc.stdout.readline()
route_table.append(line.strip().split())
if not line: break
proc.wait()
print "----------------------------------------------------------------------------------------------"
print "Route Table:"
print "%20s\t %15s\t %15s\t %15s\t %s" % ("Network Destination", "Netmask",
"Gateway", "Interface", "Metric")
for route in route_table:
if len(route) == 5:
dst, mask, gateway, interface, metric = route
print "%20s\t %15s\t %15s\t %15s\t %s" % (dst, mask, gateway, interface, metric)
I find the code above much easier to read and understand. All it does is use the subprocess module to run “route print” and write the result to stdout. Don’t be confused by the proc.stdout above. That’s the process’s stdout, not the normal stdout. We want to redirect that data to the normal stdout! To do that, we read the proc’s stdout (or some might say, the PIPE) and append each line of data to a list. Then we create a nice custom output using Python’s string formatting. Now let’s take a look at how to use Python to run Ping and Tracert.
Running Ping / Tracert with Python
Pinging with Python is pretty easy. We just need the subprocess module to do it as you can see from this snippet:
def pingIP(self, ip):
proc = subprocess.Popen("ping %s" % ip, shell=True,
stdout=subprocess.PIPE)
print
while True:
line = proc.stdout.readline()
wx.Yield()
if line.strip() == "":
pass
else:
print line.strip()
if not line: break
proc.wait()
In this code, we use wx.Yield to send the ping results to our text control in real time. If we didn’t, then we wouldn’t receive any of the ping results until ping had finished running. Note that we also use an infinite loop to grab the results. Once the results stop coming, we break out of the loop. If you look at the tracert code, you’ll see that the only difference is in out subprocess.Popen command. This would be a good candidate for refactoring, but I’ll leave that as an exercise for the reader.
Getting NIC Information with Python
Microsoft has a whole set of Python scripts on their Technet sub-site and I ended up using on them to get all kinds of good information on the Network Interface Cards (NIC) in our PCs. I won’t reproduce the code here since it’s long and we already have it above. However, it’s pretty easy to follow and I suspect that you could use WMI to get the same information if you know what you’re doing. The main part that we were interested in was the MAC and IP addresses. Let’s just extract that info from the long code and see how easy it is to get:
strComputer = "."
objWMIService = win32com.client.Dispatch("WbemScripting.SWbemLocator")
objSWbemServices = objWMIService.ConnectServer(strComputer,"root\cimv2")
colItems = objSWbemServices.ExecQuery("Select * from Win32_NetworkAdapterConfiguration")
numOfNics = len(colItems)
for objItem in colItems:
z = objItem.IPAddress
if z is None:
a = 1
else:
for x in z:
print "IP Address: ", x
print "MAC Address: ", objItem.MACAddress
Pretty easy, huh? And look! You use what looks like SQL syntax to run the query. This is why I think you can probably use WMI (in fact, that may be what it’s doing in an obtuse manner). Anyway, that’s really all there is to it.
Wrapping Up
Now you know the secrets to get various bits of networking information from your PC and how to redirect subprocess’s PIPEs to a log file and a wxPython text control. How you choose to use this information is up to you.
any reason for not using?
print '-' * 80
readability?
btw easily my favourite and probably most used python blog. awesome.