Category Archives: Gallery

Roving Networks RN XV Configuration Quick Reference Guide

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Here are some handy RN XV commands for Configuration:

1. Set the SSID and Password (WPA2) for your RNXV to connect to: (Remember that the SSID and Password are case sensitive.

set wlan ssid  <yourssid>
set wlan passphrase  <yourpass>

2. Set the Join Policy to auto associate on startup

set wlan join 1

3. Join a Network using Stored Settings

join

4. Save the configuration:  Don’t Forget or you will loose your changes

save

5. Reboot the Module: should auto join network in step 1

reboot

6. Factory Reset to Defaults (You will loose your configuration)

Factory R

7. Set the DNS Server address:

set dns address 8.8.8.8

8. Set the Name of the Host to connect to (open command) Note: for this to work the IP HOST (set ip host) should be set to 0.0.0.0

 set dns name <your.remote.host.name>

9. Set the Address of the Host to connect to (open command) Note: if this is set to 0.0.0.0 the entry in set dns name will be resolved by the DNS and used to connect to:

set ip host <0.0.0.0>

 

Marantz 2015 Receiver and BSR EQ-100X Equalizer

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Here is a Picture of my Marantz 2015 (5 Button US Version: Pretty Rare) and my BSR EQ-100X EQ. The Marantz is getting ready to celebrate it’s 40′th Birthday this year (2013). We (My Father and I purchased this for my Grandmother in 1973. I Inherited this after my Grandmother Passed in the early 1990′s. It still works great and sounds absolutely terrific. When you run Digital Files through this (say from Itunes) it adds this warmth and depth  to them that I just can’t describe you got to hear it to believe it. and NO it’s not for sale !!!!.

Vintage Marantz Model 2015 circa 1973

Vintage Marantz Model 2015 circa 1973

 

Raspberry PI Auto Start X Windows and Disable Screen Saver

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If you need to have the X Windows environment auto-start when booting the PI all you need to so is edit the /etc/rc.local file.

Here is my /etc/rc.local file with Comments

      1 #!/bin/sh -e
      2 #
      3 # rc.local
      4 #
      5 # This script is executed at the end of each multiuser runlevel.
      6 # Make sure that the script will "exit 0" on success or any other
      7 # value on error.
      8 #
      9 # In order to enable or disable this script just change the execution
     10 # bits.
     11 #
     12 # By default this script does nothing.
     13 
     14 # Print the IP address
     15 _IP=$(hostname -I) || true
     16 if [ "$_IP" ]; then
     17   printf "My IP address is %s\n" "$_IP"
     18 fi
     19 
     20 
     21 #####################################################################
     22 # Start the X Window System in the Background
     23 startx&
     24 
     25 # Give the X Window System a chance to initalize
     26 sleep 30
     27 
     28 
     29 # setup our env DISPLAY Variable for the upcomming xset Commands:
     30 export DISPLAY=:0.0
     31 
     32 # turn off the X screen Saver
     33 xset s off
     34 
     35 # turn off energy saver
     36 xset -dpms
     37 
     38 # turn off Screen blanking
     39 xset s noblank
     40 
     41 
     42 # exit with no errors
     43 exit 0
     44 
     45

Mbed Application board Temperature Offset Fix.

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My LMB75 Temperature Sensor on my Mbed application board was reading about 10 Degrees F. High after 20 min. I assume its a function of ambient (74 Deg. F. in my office) vs. heat generated on the board itself. After 20 Minutes the reading stays pretty consistent at +10 above ambient.

As a very QUICK and dirty Fix for this, I used the POT1 reading to apply to the Temp Reading as an offset. This way, I can dial in how much of an offset I need by simply turning the POT1 wheel.

Here is a code snippet of what I did:

#include "LM75B.H"

AnalogIn Pot1(P19);       // POT1 voltage reading
LM75B LMTemp(p28,p27);    // LM75B reading in Deg. C.


. . .

int main()
{

float TempFair;   // Temperature in Deg F
float TempCel;    // Temperature in Deg C 
float TempOff;    // Temperature Offset


	while(1){
		
		TempCel = LMTemp.read();  // get the reading in Deg C
		TempFair = TempCel * 9/5 + 32; // Convert to Deg F
		
		// We want a 0 to 20 Offset
		TempOff = Pot1 * 20; //Get the POT1 voltage and Multiply by 20
		
		// Apply the offset to the Deg F reading
		TempFair = TempFair - TempOff;

		// TempFair now has the correct Temperature.
		pc.printf("%.2f\r\n", TempFair);
	
		// you could also print out TempOff and Pot1
		// to see the effect of turing the POT1 wheel.
		
		. . .
		
		wait(1.0);
	}
}

Mbed Application Board

Featured

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If you have any interest in embedded programming, you gotta get one of these !!!!

Mbed Application Board

Mbed Application Board

When I received mine I was up and running in less than 10 Minutes. The Possibilities are endless

Check out www.mbed.org for more information

 

Cisco Routers Setup an SSH Server

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We used to say “Its not IF the Hard Drive will Fail….It’s When’. Applying that same logic to today’s world and we can say:

“It’s not If Crackers will try to Breach your network….it’s When”

Telnet was a Great tool in the 80′s and 90′s but in today’s interconnected world, it presents a Huge security risk. Telnet sessions are ‘in the clear’ that is to say that no encryption is performed and the entire Telnet Session can be captured by Crackers.

Telnet should Only be used on a secure line (console) directly connected to the router.

Enter SSH. SSH is a secure encrypted protocol that allows you to interact with the router over the Network or Internet.

Here are the Steps necessary to setup a SSH Server on a Cisco Router.

1. Enter you router via Telnet and gain privileged access
2. Set a hostname for your router
3. Set a domain name for your router
4. Set up a User Account and Secret Password for your Router
5. Generate 1024 bit RSA Key
6. Enable AAA New Model
7. Enable Local AAA authentication for Login
8. Set the Line access to SSH only

Here is the Cisco Dialog:

Router#config term
Router(config)#hostname [yourhostname]
Router(config)#ip domain-name [yourdomainname]
Router(config)#username [username] secret [password]
Router(config)# crypto key generate rsa
The name for the keys will be: [yourhostname].[yourdomainname] Choose the size of the key modulus in the range of 360 to 2048
for your General Purpose Keys. Choosing a key modulus greater than
512 may take a few minutes.
How many bits in the modulus [512]: 1024 % Generating 1024 bit RSA keys ...[OK]
Router(config)# *Mar  1 00:17:13.337: %SSH-5-ENABLED: SSH 1.5 has been enabled 
Router(config)# aaa new-model
Router(config)# aaa authentication login default local
Router(config)# line vty 0 4
Router(config)# transport input ssh
Router(config)# end
Router#

Notes:

1. Before you save this to NVRAM you should test your configuration by opening a new Terminal Window and SSH over to the Router. If you succeed you cna go ahead and write the config file to NVRAM.

 

IT Certification Study Materials:

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Here are the Certification Study Materials that I recommend:

A+

When it comes to A+ certification Mike Meyers (www.totalsem.com) is the man. His books are well written and easy to understand. He has the ability to take a rather dull subject and  make it interesting.

1. CompTIA A+ Certification All-in-One Exam Guide, Seventh Edition (Exams 220-701 & 220-702) [Hardcover]

Product Details

Click to go to Amazon

This massive Hardcover book is the definitive A+ reference. It covers all aspects of both exams (701 and 702) and also serves as an excellent hardware reference. This book is a monster (1376 pages) and includes a CD-ROM that is loaded with extras.
The CD-ROM includes:

  • Practice Exams for 701 & 702
  • 600+ Chapter Review questions
  • Tools and Utilities
  • Searchable E-Book

2. Mike Meyers’ CompTIA A+ Certification Passport, Fourth Edition (Exams 220-701 & 220-702) [Paperback]

Product Details

Click to go to Amazon

This book zeroes in on exactly what you need to know to Pass the A+ Exams. It is lightweight paperback format let’s you study anywhere. The included exam tips in each chapter really help you focus on potential Exam Questions. The book also includes a CD-ROM that includes:

  • Practice Exams for 701 and 702
  • Ebook in PDF Format
  • Hundreds of practice questions from the book
  • PC Tools and utilities

 

  3. Mike Meyers’ Guide to Supporting Windows 7 for CompTIA A+ Certification (Exams 701 & 702) (All-in-One) [Paperback]

Product Details

Click to go to amazon

This book focuses on the new Windows 7 topics and questions on the exams. It is a must have companion to the above two books.

  • Windows 7 interface features
  • Installing Windows 7
  • Boot Issues with Windows 7
  • and much more.

SubNetting Reference

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Here are all the possible Subnet Masks for the last three octets

Class C
255.255.255.252 /30 =        4 Addresses - 2 =        2 Hosts 64 subnets
255.255.255.248 /29 =        8 Addresses - 2 =        6 Hosts 32 subnets
255.255.255.240 /28 =       16 Addresses - 2 =       14 Hosts 16 subnets
255.255.255.224 /27 =       32 Addresses - 2 =       30 Hosts  8 subnets
255.255.255.192 /26 =       64 Addresses - 2 =       62 Hosts  4 subnets
255.255.255.128 /25 =      128 Addresses - 2 =      126 Hosts  2 subnets
255.255.255.0   /24 =      256 Addresses - 2 =      254 Hosts  1 subnet

Class B
255.255.254.0   /23 =      512 Addresses - 2 =      510 Hosts 128 subnets
255.255.252.0   /22 =     1024 Addresses - 2 =     1022 Hosts  64 subnets
255.255.248.0   /21 =     2048 Addresses - 2 =     2046 Hosts  32 subnets
255.255.240.0   /20 =     4096 Addresses - 2 =     4094 Hosts  16 subnets
255.255.224.0   /19 =     8192 Addresses - 2 =     8190 Hosts   8 subnets
255.255.192.0   /18 =    16384 Addresses - 2 =    16382 Hosts   4 subnets
255.255.128.0   /17 =    32768 Addresses - 2 =    32766 Hosts   2 subnets
255.255.0.0     /16 =    65536 Addresses - 2 =    65534 Hosts   1 subnet

Class A
255.254.0.0     /15 =   131072 Addresses - 2 =   131070 Hosts 128 subnets
255.252.0.0     /14 =   262144 Addresses - 2 =   262142 Hosts  64 subnets
255.248.0.0     /13 =   524288 Addresses - 2 =   524286 Hosts  32 subnets
255.240.0.0     /12 =  1048576 Addresses - 2 =  1048576 Hosts  16 subnets
255.224.0.0     /11 =  2097152 Addresses - 2 =  2097150 Hosts   8 subnets
255.192.0.0     /10 =  4194304 Addresses - 2 =  4194302 Hosts   4 subnets
255.128.0.0     /9  =  8388608 Addresses - 2 =  8388606 Hosts   2 subnets
255.0.0.0.0     /8  = 16777216 Addresses - 2 = 16777214 Hosts   1 subnet

Binary Values for Subnetting

                     Shorthand for Octet 
Binary      Decimal  First Second Third Fourth
1111-1111   255      /8    /16    /24   /32
1111-1110   254      /7    /15    /23   /31 
1111-1100   252      /6    /14    /22   /30
1111-1000   248      /5    /13    /21   /29
1111-0000   240      /4    /12    /20   /28 
1110-0000   224      /3    /11    /19   /27 
1100-0000   192      /2    /10    /18   /26
1000-0000   128      /1    /9     /17   /25

 

Cisco Routers: Setup a DHCP Server

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Here are the Steps necessary to set up a DHCP Server on your Cisco Router.

Before we dive right in we will need to define and document a few things:

  • Network(s) and Subnet(s) to be allocated
  • Excluded Addresses
  • Default Route
  • DNS Server Address

1. Define the Network and Subnet that you want the DHCP Server to Allocate addresses from.

example: Network:192.168.1.0 Subnet Mask:255.255.255.0

The above will allocate 253 Addresses from 192.168.1.1 to 192.168.1.254. If we needed more than 253 Address we just alter the subnet mask:

example: Network:192.168.0.0 Subnet Mask:255.255.254.0

The above will allocate 510 Addresses from 192.168.0.1 to 192.168.1.254

2. Define the Addresses in the above Ranges that you Want Excluded. Typically you will want to exclude the First address for the default route (router), but you may also want to exclude several for Servers, etc.. I like to reserve at Least the First Five Addresses.

Addresses 192.168.1.1 - 192.168.1.5 are reserved..The First Five Addresses

3. Define the Default Router for the Address range. Typically this will be the First Address in the range..But not Always…

Network:192.168.1.0 Subnet Mask:255.255.255.0
The default route should be 192.168.1.1

4. Define the DNS-Server that you which to assign to the Clients in the Address Range. I use 8.8.8.8 because I can never remember my ISP’s address,but you may have an internal DNS Server to point to or use your ISP’s server.

DNS Server: 8.8.8.8

5. Define an arbitrary name for your Address Range. I like to use a Combination of a Name and Number in case I have more than one Network to Allocate. I typically use the following naming convention.

insideDHCPx where x is a sequential number. 
so...
insideDHCP1 would be my first Pool and 
insideDHCP2 would be my second and so on...

6. Finally we are ready to configure our router: In the following example I will be defining two DHCP Pools for two different VLANS that I have previously configured.

VLAN1 is 192.168.1.0  255.255.255.0
Default Route will be 192.168.1.1
Reserved Addresses are 192.168.1.1 – 192.168.1.5
DNS Name server will be 8.8.8.8

VLAN2 is 10.0.1.0  255.255.255.0
Default Route will be 10.0.1.1
Reserved Addresses are 10.0.1.1 – 10.0.1.5
DNS Name Server will be 8.8.8.8

Here is the Router configuration Dialog:

telnet <routername>
Password: <your Secret Password>
Router>enable
Password: <your Supervisor Password>
Router#config term
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#ip dhcp pool insideDHCP1
Router(dhcp-config)#network 192.168.5.0 255.255.255.0
Router(dhcp-config)#default-router 192.168.5.1
Router(dhcp-config)#dns-server 8.8.8.8
Router(dhcp-config)#ip dhcp pool insideDHCP2
Router(dhcp-config)#network 10.0.1.0 255.255.255.0
Router(dhcp-config)#default-router 10.0.1.1
Router(dhcp-config)#dns-server 8.8.8.8
Router(dhcp-config)#exit
Router(config)#ip dhcp excluded-address 192.168.1.1 192.168.1.5
Router(config)#ip dhcp excluded-address 10.0.1.1 10.0.1.5
Router(config)#exit
Router#show run

7. We are Done! Your DHCP Configuration section should resemble this:

ip dhcp excluded-address 192.168.1.1 192.168.1.5
ip dhcp excluded-address 10.0.1.1 10.0.1.5
!
ip dhcp pool insideDHCP1
   network 192.168.1.0 255.255.255.0
   default-router 192.168.1.1 
   dns-server 8.8.8.8 
!
ip dhcp pool insideDHCP2
   network 10.0.1.0 255.255.255.0
   default-router 10.0.1.1 
   dns-server 8.8.8.8 
!

There are many more things we can do with DHCP that are not covered here….Perhaps we will cover them in a future article…

 

Mac OS X TFTP Server Setup

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TFTP (Trival File Transfer Protocol) is not enabled by default on Mac OS X. Here are the Steps that you need to take to set up  a TFTP server on your Mac.

1. Determine the IP Address of your MAC.

Open Network preferences and look at the Address assigned to your Ethernet Adapter or WiFi Adapter and make a note of this address. You will need it later to connect.

Note: If you are using DHCP to connect…Remember if you reboot your IP Address is subject to change. You may want to consider using a Static IP Address.

2. Determine the Location where you want the TFTP server to Share out.

Note: By default Mac OS X uses the /private/tftpboot directory for the TFTP Share. I  was not happy with this so I created a separate directory for the TFTP server.

I called my Directory /public and I set the Permissions to rw_rw_rw_ (666).

MacOSX:~warthog$ sudo mkdir /public 
MacOSX:~warthog$ sudo chmod 666 /public

3. Create a Backup of the Original Configuration File.

MacOSX:~warthog$ sudo cp /System/Library/LaunchDaemons/tftp.plist /System/Library/LaunchDaemons/tftp.plist.org

4. Change the Configuration File.

Edit the .XML File called /System/Library/LaunchDaemons/tftp.plist

MacOSx:~warthog$ sudo vi /System/Library/LaunchDaemons/tftp.plist

Look for the line that contains /private/tftpboot and change to the directory you setup in Step 2.

11 <key>ProgramArguments</key> 
12         <array> 
13            <string>/usr/libexec/tftpd</string> 
14                 <string>-s</string> 
15                 <string>/private/tftpboot</string> 
16         </array> 
17

5. Start up the TFTP Daemon

MacOSx:~warthog$ sudo vi launchctl load -w /System/Library/LaunchDaemons/tftp.plist

6. Create a Test File to Send and Receive

Go to the /public Directory and create a test file

MacOSx:~warthog$ sudo cd /public 
MacOSx:~warthog$ sudo touch test.file 
MacOSx:~warthog$ sudo chmod 666 test.file

7. Test receiving and sending a file

Note. This version of TFTP will NOT let you create a new file. That is to say that the File MUST exist and you MUST have permissions 666 to write to it for a successful transfer.

8. Stopping the TFTP Server.

I don’t like to leave my TFTP server running all the time so when I am done I usually shut it down.

MacOSx:~warthog$ sudo launchctl unload -w /System/LaunchDaemons/tftp.plist

 

 

 

LPIC-201 Study Notes

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System Startup and Advanced System Management:

Customizing System startup and Boot Processes

Boot Time Sequnce:

1. Cpu Initialization

2. Firmware init hardware subsystems and memory check

3. Firmware directs the computer to look for boot code (Stage 1 Boot Loader)

4. Stage 1 Boot loader may load additional stages or Load the Kernel

5. Kernel looks for its first process (Usually /sbin/init)

7. Init process reads config files and launches other programs

Grub Legacy and Grub 2

Grub Legacy config file is /boot/grub/menu.lst or /boot/grub/grub.conf

Grub Legacy refers to disk drives via (hd0) = First Hard Drive in the System

Grub Legacy Drive mappings can be found in the /boot/grub/device.map

(hd0,0) = First Hard Drive/First Partition

Global Grub legacy Options

1. default= (Default OS) Tells Grub wqhat OS to boot

2. timeout= (Timeout how long in seconds to wait before booting default os)

3. splashimage= (Points to a graphic file to be displayed during grub.

 

Per-Image Grub Legacy Options:

1. title begins a per-image stanza and specs the label to display for the image

2. root Specs where the location of the /boot partition is (/boot can be a seperate partition)

3. kernel Specs the location of the kernel and the option to pass to it

4. initrd Specs an intitial ram disk

5. rootnoverify   Used nor Non Linux OS i.e. Dos/Windows

6. chainloader tells grub legacy to pass control to another boot loader (Dos/Windows)

 

Cisco Router and Switch Quick Reference

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Save Running Configuration to NVRAM:

router#copy run start

Get Startup Configuration from NVRAM:

router#copy start run

Reload Configuration from NVRAM:

router#reload

Manually Set the Date and Time:

router#config term
router#clock timezone EST -5
router#clock summer-time EDT recurring
router#exit
router#clock set 08:30:00 Jan 31 2013
router#show clock

Setup an internal NTP Server for your network

router#config term
router(config)#ntp server ntp.pool.org
router(config)#ntp master 3
router(config)#end
router#show ntp status
router#show ntp association
router#show clock

Setup an internal NTP client pointing to your internal NTP Server
Note: Assume your Internal Server’s Address is: 192.168.200.1

router#config term
router(config)#ntp server 192.168.200.1
router(config)#end
router#show ntp status
router#show ntp association
router#show clock

 Send the router an Escape Sequence for Failed Traceroute

Ctrl + Shift + 6
Ctrl + Shift + 6

Disable the Domain Lookup of mis-typed commands

router#config term
router(config)#line con 0
router(config-line)#transport preferred none
router(config-line)#line vty 0 4
router(config-line)#transport preferred none
router(config-line)#end

 Disable the Cisco File Prompt Dialog

router#config term
router(config)#file prompt quiet
router(config)#end

Enable the Cisco File Prompt Dialog

router#config term
router(config)#file prompt alert
router(config)#end

 Enable a Default Route using RIP

router#config term
router(config)#router rip
router(config)#default-information originate
router(config)#end

 

 

 

 

LPIC-2 Exam 201 Detailed Objectives

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201 Linux Kernel

201.1 Kernel Components
201.2 Compiling a Kernel
201.3 Patching a Kernel
201.4 Customize, Build and install a custom kernel and kernel modules
201.5 Manage/Query Kernel and Kernel modules at runtime

202 System Startup

202.1 Customizing system startup and boot processes
202.2 System recovery

203 Filesystem and Devices

203.1 Operating the Linux Filesystem
203.2 Maintaining a Linux Filesystem
203.3 Creating and configuring filesystem options
203.4 udev device management

204 Advanced Storage Device Administration

204.1 Configuring RAID
204.2 Adjusting Storage Device Access
204.3 Logical Volume Manager

205 Networking Configuration

205.1 Basic Networking Configuration
205.2 Advanced Network Configuration and Troubleshooting
205.3 Troubleshooting network issues
205.4 Notify users on system-related issues

206 System Maintenance

206.1 Make and install programs from source
206.2 Backup operations

207 Domain Name Server

207.1 Basic DNS Server configuration
207.2 Create and maintain DNS zones
207.3 Securing a DNS server

 

 

VI Quick Reference

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FunctionCommandFunctionCommandFunctionCommand
Enter Cmd ModeEscAdd New Line after Current LineoEnable Line Numbers:set nu
Save File:wAdd New Line before Current LineONext Instance of word*
Abort:q!Read file and insert at current line:r Previous Instance of Word#
Beginning of Line0Put after current PositionpSearch and Replace:%s/targ/repl/flag Flags g=All c=Confirm
End of Line$Put before current PositionPRepeat Last Search&
Start of File1GRewrite whole lineCJoin LinesJ
End of FileGDelete to leftxRepeat Last Command.
n'th Line:nDelete to rightXUndo all Changes to lineU
Top of ScreenHDelete to End of LineDSplit Screen:N
Middle of ScreenMDelete Linedd or :dVisual Modev
Bottom of ScreenLSearch Forward/
Matching Bracket%Search Backward?
Insert before cursoriNext matchn
append after cursoraPrevious matchN
Insert before lineI
Append after lineA
Overwrite 1 characterr
Overwrite Many charactersR

 

UTP Cable Categories

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CategoryMaximum Rated SpeedTypical Use
Cat 11 MbpsVoice Only - Regular Analog Phone Lines; Not Used for Data Communications
Cat 310 MbpsEtherNet over UTP at 10Mbps (10baseT)
Cat 5100 MbpsEthernet over UTP at 100Mbps 100BaseT
Cat 5e1 Gbps (1000 Mbps)Ethernet over UTP at 1000Mbps 1000BaseT
Cat 610 Gbps10 Gigabit Ethernet 10GbE
Cat 6a10 Gbps10 Gigabit Ethernet 10GbE

TCP/IP well known ports

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Here are some Common TCP/IP Port Numbers

Service NamePort Number
FTP data port20
FTP control port 21
SFTP (SSH)22
SSH, SCP22
Telnet23
SMTP25
TACAS/TACAS+49
DNS53
TFTP69
HTTP80
Kerberos88
POP3110
NetBIOS137-139
IMAP4143
SNMP161
LDAP389
HTTPS443
IPsec(VPN with IKE)500
LDAP/TLS636
LDAP/SSL636
L2TP1701
PPTP1723
Terminal Services3389
Remote Desktop Services3389