Build a private network between two physical hosts in ESXi 4.0 for VM guests

Similar Questions

• Why is no longer a faster network between two different hosts?

  Hello community!

  I need help in this mystery.

  I have three computers different virtual, all of them with e1000 (also I tried all VMs with vmxnet3) and the latest vmware tools.

  Two of this mV, are in the same physical host (ESXi 5.5.0 2068190). Call for example: VM - 1A & VM - 2A

  Another virtual machine, is in another physical host (ESXi 5.5.0 2068190). Call VM-1 b

  Both ESXi hosts are connected with two cards 10 Gbit network with load Balancing: "From hash IP route" and detection: "link status only.

  Traffic Shaping is disabled in all Ports.

  The environment is very clean, and we have more VMs that can disrupt the test (or inappreciable).

  VM - 1a: 10.12.50.201 - physical host ESX - A

  VM - 2A: 10.12.50.202 - physical host ESX - A

  VM-1 b: 10.12.50.200 - physical host ESX - B

  Why I don't see better network speed reference, when two virtual machines send something two physical host is different than when the two virtual machines are in the same physical host?

  It is not a question of "iperf", I used the other test with CPS and I had the same speed.

  Thank you very much!!!

  PS: The physical host computers are: Dell PowerEdge r.620 - 16-core Xeon - 384GB RAM

  

  Have you tried to move your VM on different hosts to the same host?

  Your names of:

  VM - 1 a host has

  -VM-1 b on Hots B

  ToDo

  Now move VM-1B for A Host and repeat the test (two virtual machines on the same host). What happens now to the speed?

  Check

  -How is the CPU usage during the test we Host-A, if you have 2 virtual machines on this host?

  -What is your ratio of P2V CPU? (overprovisioning?)

  What it could be

  -Host doesn't have enough CPU power to serve the two virtual machines (or over-provision P2V related problem). But for me no sense if I see your config server with 16cores.

  -It is not a host but a related problem of VM (perhaps it depends on the VM - A2). Makes the most sense for me (your test is to check)

  Please share the results

• Private network between two or more virtual machines?

  I've been running an educational network configuration kind of base on esxi to work to teach their colleagues how running things. To do this I create a separate switch, connect the virtual machines to (only) the switch and run Ethereal on a machine with network in promiscous mode.

  Now, I would do it on my laptop. Can I do this with the merger? Can I network machines without connecting to the host (to ensure that there is no additional noise)? Can I configure a NIC in promiscous mode?

  sflanders wrote:

  I think the important part of the question is in regards to the networking VMs as they see, but not the host (btw merger networking of information: http://communities.vmware.com/docs/DOC-2527). Basically, it boils down to the host option only and the answer is no.

  In fact, the answer is yes because after that Virtual Machines are started can be simply down the vmnet1 network card and thus isolate the virtual machines between them.

  In other words on the network of Machines target virtual host-only and then start them up to the point where they receive their IP address DHCP host-only server, then in a Terminal on Mac (/ Applications/Utilities /) use the following command in low only Ethernet adapter of the host host.

  sudo ifconfig vmnet1 down
  

  Now the target of the Virtual Machines will be able to communicate only with each other and not the host.

  Note: You must down only Ethernet adapter of the host host after the virtual machines have acquired their IP addresses, because if you down the adapter before the Virtual Machines will not receive their IP addresses.

  The host only allows virtual machines to see the host, but it really shouldn't be any other "noise". Why do you have to be concerned about this?

  On the question of the noise, I think that VMware Fusion actually uses virtual hubs, no virtual switches (even if by mistake, VMware calls virtual switches), there is a risk of bleeding, and this has been discussed ad nauseam and various forums.

• Private network between hosts in different regions

  Dear guys,

  I have just asked me if it would be possible that 2 hosts in different regions (EU-NA) can communicate on a virtual private network over the Wan.

  How to perform I thought to arrive at:

  -import the host NA in a cluster in the EU vcenter

  -create a tmp DVS and attach 2 guests to the DVS

  -create a private VLAN GP and configure 2 virtual machines with this PG = > they just have to communicate with each other, this is just a test

  The question I have is this: given that the 2 hosts are in different regions, traffic of 2 VMs would go across the WAN using the DVS even?

  Thanks in advance.

  Daniele

  I thought on it and it is not possible, DVS and a dummy network, we have L2 and we have no tools for the encapsulation of L2 to L3, I have no NSX.

  I will give points me

  Daniele

• How can I make a network between two databases?

  Hello all;
  

  Is going to set up oracle 10 g - (

  I try to Exchange data between two different databases.)
  Each database is configured in different operating systems.
  
  For ex: a database of windows XP (separate virtual machinne)
  a database of linux rhel (separate virtual machinne)
  
  I'm waiting for suggestions...
  
  Thank you...
  
  Published by: 969352 on March 19, 2013 10:04

  969352 wrote:

  What virtualization product do you use?

  * #* vmware - toolbox - cmd - v
  8.1.3.9911 (build-203739)

  VMWARE product information:

  Version: 7.0.0 build - 203739

  Ok. You will need to ensure that the ip addresses you assign to your virtual machines are in the same subnet that the adapter created by the installation of vmware. Once you get the fixed basic network installation, you can treat these virtual machines like any machine in your data center. Forget the vm console and access it exactly as you would for any remote server - putty for the Linux and Windows Remote Desktop to the Windows machine.

  To a prompt on the host computer, post this:

  c:> ipconfig -all
  

  You will get feedback on multiple net cards, of which two are identified as with vmware - vmNet1 and vmNet8. Note the IP addresses of the two. We'll need later.
  You'll also need to know how you have configured the network cards on your virtual machine - NAT, bridged, hostonly?

  Note that these issues are out of scope for this forum. I don't mind helping, but I don't have an installation of vmware for details of the reference.

  Which have really tried to do? ( Data transfer )

  I tried to Exchange data from windows to linux DB database

  It's pretty vague. Exactly how did you try to "Exchange data"? A SQL using a db_link? import/export? Pigeons?
  >

  Where are you stuck?

  I don't know, how to set up the ip address and the necessary information for the windows database.

  Configuration of an IP address is purely a matter of admin OS and out of range for this database forum.
  Google is your friend, but only if you use: [url http://lmgtfy.com/?q=configure+windows+ip+address] http://lmgtfy.com/?q=configure+windows+ip+address
  >

  It's all Edstevens... Thank you...

• "Limited connection" when you configure the network between two computers XP.

  Original title: Configuration of the network connection

  Trying to establish a network connection between two home PCs., both running Windows XP Pro. Have been through the network on both PC Setup Wizard but, they still say limited, in fact no connection. I use an Ethernet cable between the two Crusader. If it is true what I'm doing wrong?

  Thanx Terry

  Old but good, networking tips from MVP Malke, MS:

  The best and simplest is to buy a wireless router. This way you get Internet connectivity both machines and the added benefit of security more between you and the Internet. Then you configure your network wireless safely, and then you configure file/printer sharing. Here is information on the implementation of a router and also in networking. It seems long, but don't be intimidated. Setting up a router and the LAN of sharing between two computers takes about 15 minutes.

  The router configuration

  Setting up a router is simple enough. Normally, you run the CD that came with the router and follow the instructions. If you're running Vista, maybe the CD that came with the router does not work; I do not know this. But you can set up the router without the CD. Note that if you have Internet cable for the connection you have just set up the router to DHCP (or there may even be a choice of cable to choose). If you have DSL Internet, you select TRP usually and enter the username and password you selected when you initially set the DSL connection. So:

  1. turn off the power to your cable modem.

  2. attach a cable (usually supplied with the router) course Ethernet cat5e Internet/WAN port of the router to the Ethernet port on the cable modem.

  3. connect the ethernet cable cat5e from the network card in your computer to one of the ports on the router. If you do not have an ethernet cable (because you were using USB), you will need to go to the store and buy a.

  4. turn on the cable modem. After that all the lights are on, turn on the router.

  To configure the router:

   

  Have a computer connected to the router with an ethernet cable. Examples given are for a Linksys router. See the manual of your router or the router mftr's Web site. for the parameters by default if you don't have a Linksys. Open a browser such as Internet Explorer or Firefox and in the address bar type:

  http://192.168.1.1 [Enter] (it is default IP address of the router, which varies from router to router then check your manual)

  This will bring you to the login screen of the router. The default username is blank and the Linksys default password is "admin" without the quotes. Enter this information. You are now in the configuration of the router utility. Your configuration utility may be slightly different from mine.

  Click the Administration link at the top of the page. Enter your new password. MAKE A NOTE SOMEWHERE THAT YOU WILL NOT LOSE. Re-enter the password to confirm it, and then click Save settings at the bottom of the page. The router will reboot and show you the box of connection again. Do not fill in the user name and put it in your new password to enter the configuration utility.

  Now, click on the link wireless at the top of the page. Change the network name (SSID) wireless by default to something, you'll recognize. I suggest that my clients not use their surname as the SSID. For example, you might want to name your network wireless network "CastleAnthrax" or similar.

  Click on save settings and when you get the prompt that your changes were successful, click the wireless security link which is just beside the Basic Wireless Settings link (where you changed your SSID). If you have a newish computer, you will be able to affect security WPA2-Personal Mode. Do this and enter a password. The password is what you enter on all computers that are allowed to connect to the wireless network. MAKE A NOTE SOMEWHERE THAT YOU WILL NOT LOSE.

  At this point, your router is set up and if the computer that you use to configure the router will normally connect wireless, disconnect the Ethernet cable and wireless of the computer should see your new network. Enter the password you created to join the network and start surfing.

  *****

  B. file/printer sharing of

  Excellent, comprehensive, but easy to understand article on sharing files/printer under Vista. Contains information about sharing printers and files, and the folders:

  http://TechNet.Microsoft.com/en-us/library/bb727037.aspx

  For XP, start by running the Network Setup Wizard the on all machines (see warning in section A below).

  Problems sharing files between computers on a network are usually caused by 1) a misconfigured firewall or a firewall neglected (including a dynamic firewall in a virtual private network); or (2) inadvertently run two firewalls such as the firewall of Windows and a third-party firewall. and/or (3) do not have accounts to the same users and passwords on all computers in the workgroup. (4) tries to create actions where the operating system does not.

  A. configure the firewall on all machines to allow traffic to local area network (LAN) as being approved. With the Windows Firewall, it means which allows file sharing / print on the Exceptions tab normally run the XP Network Setup Wizard will take care of this for these machines. The only "witch hunt", it will turn on the XPSP2 Windows Firewall. If you are not running a third-party firewall or you have an antivirus with "Internet Worm Protection" (like Norton 2006/07) which acts as a firewall, you're fine.  With a third-party firewall, I usually set up the allocation of LAN with an IP address range. E.g. would be 192.168.1.0 - 192.168.1.254. Obviously you would substitute your correct subnet. Do not run more than one firewall. DON'T STOP FIREWALLS; CONFIGURE THEM CORRECTLY.

  (B) to facilitate the Organization, put all computers in the same workgroup. This is done from the System applet in Control Panel, the computer name tab.

  C. create the counterpart of the user accounts and passwords on all machines. You do not need to be logged into the same account on all machines and assigned to each user account passwords can be different; accounts/passwords just need to exist and to match on all machines. DO NOT NEGLECT TO CREATE PASSWORDS, EVEN IF ONLY OF SIMPLE. If you want a machine to boot directly to the desktop (a particular user account) for convenience, you can do this. The instructions on this link work for XP and Vista:

  Set up Windows to automatically connect (MVP Ramesh) - http://windowsxp.mvps.org/Autologon.htm

  D. Si one or more of the computers is XP Pro or Media Center, turn off Simple file sharing (Folder Options > view tab).

  E. create share as you wish. XP Home does not share the users directory or the Program Files, but you can share folders inside those directories. A better choice is to simply use the Shared Documents folder. See the first link above for more information on Vista sharing.

  F. you have the job of file sharing (and tested by exchanging a file between machines), if you want to share a printer connected locally to one of your computers, share of this machine. Then go to the printer mftr Web site. and download the latest drivers for the correct system. Install them on the target machines. The printer must be collected during the installation procedure. If this isn't the case, install the drivers and then use the Add Printer Wizard. In some cases, printers must be installed as local printers, but it is outside this response.

• Need help to set up a network between two Windows 7 computers

  I have two Windows 7 computers at home: one is a desktop computer that is connected directly to the internet (with a network cable), and the other is a laptop computer that is not directly connected to the internet with a network cable.  We have a configuration of wireless network for your laptop is set up of this network and has internet access.

  What I want to do is set up a network between the two of them, so that the laptop can access the printer that is directly connected to the desktop computer.  I got this configuration when both computers are Windows XP, but since we their past to Windows 7 I can not it works.  I tried to create a home network, I set the printer on sharable and given him a name, but I can't access it on the laptop.

  The printer is actually a photocopier, but it is directly connected to the desktop computer.  In fact, it is connected to the router than the phone company provided.  But we want the laptop to be able to access it and use it.  As I said, we had this configuration when these computers are computers Windows XP, but I tried following the instructions to do this for Windows 7 and I can't make it work.

  Also, I'm not that computer savy, so please if you tell me to run a program it please tell me how to find and launch this program.

  Thanks for any help.

  Hello

  Welcome to the Microsoft Community Forum.

  Before you start with the troubleshooting steps, I would need some information on the subject, so that we can better help you.

  1. What happens exactly when you try to access the shared printer on the network home?
  2. You receive an error message/code?
  3. Have you tried sharing the computer and using collective housing resources?

  As you mentioned, you can share printer for two other computer running on Windows 7, you can check the items below that will provide you with information on how to work with the host group, and also another article that will you provide steps on how to share a printer on the network.

  Homegroup from start to finish

  Share a printer

  Hope that the information provided is useful. Let us know in case you need additional assistance.

  Thank you.

• Create a simple internal network between two or more virtual machines

  Hello guys,.
  I just wanted to ask how to create an internal network between several virtual machines without the host must be a part of.

  I don't want that your network has a NAT, but I want to HOST a part of another network.

  
  I tried the changes on network cards, but does not work...
  Obviously with VMware Workstation 8

  Yes, your "Virtual Machine settings" - screenshot #1 - Select VMnet2 (for example).  Do this for each customer that you want on this private network, "Guest-only.  Note that you need to configure the network settings on each client within each guest OS; or have a guest to be a server with a dhcp server running that other clients can obtain an IP address configuration of.

• Catalyst 3560 liaison network between two servers ubuntu 12.04

  Hello world

  I'm trying to transfer data with more than 1 Gbit/s between two servers, but I just get a card (approximately 1 Gbps) NETWORK performance. Here is my configuration:

  srvnettest1 and srvnettest2 are two 12.04 servers ubuntu with three network cards in each. management eth0, eth1 and eth2 are network cards that should work as a team. ;-) Here are the relevant parts of fit it:

  [email protected]/* */:~# less /etc/network/interfaces
  ...
  auto bond0
  iface bond0 inet static
  address 172.16.200.100
  netmask 255.255.255.0
  bond-mode 4
  bond-miimon 100
  bond-slaves none
  bond-lacp-rate 1
  bond-primary eth1 eth2
  auto eth1
  allow-bond0 eth1
  iface eth1 inet manual
  bond-master bond0
  auto eth2
  allow-bond0 eth2
  iface eth2 inet manual
  bond-master bond0
  ...
  
  

  
  [email protected]/* */:~# less /etc/network/interfaces
  ...
  auto bond0
  iface bond0 inet static
  address 172.16.200.200
  netmask 255.255.255.0
  bond-mode 4
  bond-miimon 100
  bond-slaves none
  bond-lacp-rate 1
  bond-primary eth1 eth2
  auto eth1
  allow-bond0 eth1
  iface eth1 inet manual
  bond-master bond0
  auto eth2
  allow-bond0 eth2
  iface eth2 inet manual
  bond-master bond0
  ...
  
  

  It's the switch configuration (btw, this is a version of IOS in course WS-C3560G-48TS 12.2 (55) SE)

  Switch#show running-config
  ...
  interface Port-channel10
  switchport access vlan 200
  switchport mode access
  !
  interface Port-channel20
  switchport access vlan 200
  switchport mode access
  !
  interface GigabitEthernet0/1
  switchport access vlan 200
  switchport mode access
  channel-group 10 mode active
  !
  interface GigabitEthernet0/2
  switchport access vlan 200
  switchport mode access
  channel-group 10 mode active
  !
  interface GigabitEthernet0/3
  switchport access vlan 200
  switchport mode access
  channel-group 20 mode active
  !
  interface GigabitEthernet0/4
  switchport access vlan 200
  switchport mode access
  channel-group 20 mode active
  ...
  

  This is my summary etherchannel:

  Switch#show etherchannel summary
  Flags:  D - down        P - bundled in port-channel
  I - stand-alone s - suspended
  H - Hot-standby (LACP only)
  R - Layer3      S - Layer2
  U - in use      f - failed to allocate aggregator
  M - not in use, minimum links not met
  u - unsuitable for bundling
  w - waiting to be aggregated
  d - default port
  Number of channel-groups in use: 2
  Number of aggregators:           2
  Group  Port-channel  Protocol    Ports
  ------+-------------+-----------+-----------------------------------------------
  10     Po10(SU)        LACP      Gi0/1(P)    Gi0/2(P)
  20     Po20(SU)        LACP      Gi0/3(P)    Gi0/4(P)
  

  My test tools are nuttcp (by transfer) and bmon (to watch what is happening during the transfer). Unfortunately, I am not able to transfer more than 1 Gbps:

  [email protected]/* */:~# nuttcp -i1 172.16.200.100
  97.1875 MB /   1.00 sec =  815.2409 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.4763 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.7321 Mbps     0 retrans
  98.1250 MB /   1.00 sec =  823.1001 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.5306 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.7560 Mbps     0 retrans
  98.1250 MB /   1.00 sec =  822.9890 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.6753 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.5528 Mbps     0 retrans
  98.0625 MB /   1.00 sec =  822.7058 Mbps     0 retrans
  982.5000 MB /  10.03 sec =  821.9606 Mbps 21 %TX 37 %RX 0 retrans 0.32 msRTT
  

  In bmon, I see that a NIC (eth1) of bond0 the uplink and the other a (eth2) made the downlink:

  #   Interface                RX Rate         RX #     TX Rate         TX #
  qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
  srvnettest2 (source: local)
  0   lo                         0.00B            0       0.00B            0
  1   eth2                     269.26KiB       4175       0.00B            0
  2   eth1                     123.00B            0     102.56MiB      71030
  3   eth0                     179.00B            2     491.00B            1
  4   bond0                    269.38KiB       4176     102.56MiB      71030
  

  I tried a lot of things, but now I have no idea what to do or what to try next. It is true that I have no deep understanding of Cisco etherchannels yet, so I guess that my mistake is somewhere in the IOS configuration.

  Thanks a lot for your support and welcome to Germany

  Stephan

  Hello Stephan,

  With EtherChannels, a single flow (the flow of images/packages with the same source and destination) is always carried by a single link only. Implementation of Cisco implements not balancing on connections in an EtherChannel load by package, and it avoids a reason: executives could get reorganized, something this plain Ethernet never should do. This means that you will not see an improvement in bandwidth on the speed of a single link to your EtherChannel for a single stream. It is only the overall bandwidth for several stream which increases. The advantage of EtherChannel becomes therefore obvious that if your server starts many conversations and several stream handling.

  Best regards

  Peter

• The DDE network between two PCs running windows server 2003

  We seek to transfer data between two excellent sheets (Office 2003). Two excellent books are on different PCs running windows server 2003 and office 2003. The two PC's belonging to the same workgroup. One of them being run by Siemens PCs 7 process control system. I have ensurred running on both PC Netdde.exe. When excellent both books are on the same server they connect perfectly. When I run the client excel book on the other Pc (without changing something in the formulas of cells) the connection is lost. The DDE connection is approved on the PC server and this connection permission is full control for everyone. What is perhaps the reason for this problem? I think I missed a point. Can I get help for this. Thanks in advance for you.

  Hello

  Your question of Windows is more complex than what is generally answered in the Microsoft Answers forums. It is better suited for the IT Pro TechNet public. Please ask your question in the appropriate Forum TechNet. You can follow the link to your question:
  http://social.technet.Microsoft.com/forums/en-us/categories/

• Establishment of an Ad - hoc network between two - troubleshooting - vista laptop

  Hello

  I have two latops at home. One is an hp compaq presario and the other is a sony vaio. Both runs on windows vista Home premium. I have a wired internet connection (a laptop connected to the internet with a LAN cable). I want to share internet for two laptops using the adhoc network. When I tried to do, it worked fine the first time, but now it doesn't connect any more. Sometimes it says "windows cannot set up adhoc network. Sometimes he created successfully, but the other latop cannot connect to it, identify the problem as a "network cable is unplugged" (this happens even when when I switch computers laptops).

  I really need help with that. I'm not a technician, so please teach me any changes I should make to network settings etc, or is it one cheap way without a router to connect the two?

  Thank you!

  
  

  
  

  Hello

  You must create an Ad - Hoc connection and use Vista ICS.

  http://Windows.Microsoft.com/en-us/Windows-Vista/set-up-a-computer-to-computer-ad-hoc-network

  http://Windows.Microsoft.com/en-us/Windows-Vista/using-ICS-Internet-connection-sharing

  Jack-MVP Windows Networking. WWW.EZLAN.NET

• Private of IPSec VPN-private network between ASA and router

  Hello community,

  This is first time for me to configure IPSec VPN between ASA and router. I have an ASA 5540 at Headquarters and 877 router to EH Branch

  Headquarters ASA summary.

  Peer IP: 111.111.111.111

  Local network: 10.0.0.0

  Branch

  Peer IP: 123.123.123.123

  LAN: 192.168.1.0/24

  Please can someone help me set up the vpn.

  Hello

  This guide covers exactly what you need:

  Establishment of ASDM and SDM - http://www.netcraftsmen.net/resources/archived-articles/273.html

  Tunnel VPN - ASA to the router configuration:

  http://www.Cisco.com/en/us/products/ps5855/products_configuration_example09186a0080a9a7a3.shtml#ASDM

  Kind regards

  Jimmy

• How to connect virtual networks to the physical host network?

  I currently have 1 HP Microserver with IP 192.168.0.10 that is on my home network which takes place in ESXi5 as the operating system.

  Then I have a separate network of the VM on the host with the IP addresses of 192.168.10.x. I have 2 x 2 Machines virtual ESXi Win Svr 2008 (DC & vCenter) and 1 WIn7.

  How, or even not at all, can set up a link to my VM network on ranges 192.168.10.x to my host's network?

  I currently have all advanced VM to my virtual domain as the default gateway on 192.168.10.1 controller.

  Am I missing something really obvious? I am new to VM and network (that you can probably find).

  Any help appreciated.

  Thanks in advance. Questions please ask.

  Your default gateway 192.168.10.1 there 192.168.0.x network access? You can get it... or, you can add a second nic all virtual machines, to a portgroup on the same vSwitch as the management what IP vmkernel resides.

• Vmfs only store data on two physical disks on ESXi host?

  I have an ESXi host with one disk of 250 GB and you want to add another disk of 250 GB to the host.  Is it possible to have two discs in the Act on the host as data store single vmfs?  This is a test machine and there is no shared storage (nfs, LUNs, etc.) available.  Can I add a measure after adding the second drive to the host?

  Thank you

  Ken

  Yes it is possible and it's called covering vmfs. However this is not recommended as any failure on one of the disc would render the whole vmfs unusable.

• Flow network between two PC

  Hey guys,.

  I'm developing a program to communicate a tablet that uses Win10 (PC1) to your laptop at the office (PC2). They are both connected to wifi even. The thing is, PC1 uses LabVIEW 2015 and PC2 LabVIEW 2014. After some tests, using the screw that I created and examples on the Finder of the example, I can't connect them and the screw got stuck in 'Create network Stream final point writer' and 'Create Network Stream Reader Endpoint"(constant of-1 to Timeout).

  I use this white paper as a reference https://zone.ni.com/reference/en-XX/help/371361L-01/lvconcepts/endpointurls/

  I already checked the IP address I used is correct, the only thing I see which can get in the way for this communication at work

  Is it possible to communicate with the different versions?

  is there another method to transfer data from one pc to another in the same network, different projects, more effectively?

  You can try the standard TCP/IP connections.  I would use the STM library if you go this route.  It is a free library created by systems engineers OR.  If you cannot make a TCP connection, then you probably have firewall and/or network issues.