Home Office Network

Check TCP Port Status (Open or Closed)

Some times we need to check the TCP port status of a remote computer or network device/equipment.
for example, to see if a remote web server (port 80) is open, to see a remote H.323 VOIP gateway signalling port 1720 is open for you.
Here is a simple way to check the TCP port.
Telnet is a useful network command /tool which is built in with Windows 2000/XP/Vista

To check the TCP port status :
(1)Come to Command Prompt mode of your computer.
(2) Type: Telnet remote IP address or domain name Port number and hit enter. note: between IP address and port number, you need a space.
for exmple to check Yahoo.com’s web server :
telnet www.yaho.com 80
for exmple to check a remote voip gateway port 1720 status :
telnet xxx.xxx.xxx.xxx 1720
If the port is open, the screen will be cleared immediately and only the cursor is blinking on the screen.
if port is closed, it will show ” Connecting To www.yahoo.com” ,then show you ” Could not open a connection to host on port, Connect failed”

TCP Port Status (Hoe Network TCP Port numbers)

USB over IP   (Network-enabled USB hub)

*  Network-enabled USB hub
* Access and monitor USB peripheral devices over TCP/IP network
* Works with existing POS or other application software
* Live video feed with Watchport®/V

AnywhereUSB is a network-enabled USB hub. It is the first remote networking solution to utilize RealPort® USB, Digi’s patented USB Over IP® technology, making it easy to connect USB devices anywhere on a wired or wireless LAN, while eliminating the need for locally-attached host PCs.

AnywhereUSB/5 provides five USB ports, which deliver the same Plug and Play user experience as onboard USB ports. Software drivers are loaded onto a host PC or server, enabling remote devices to communicate with the host, without changing existing application software. Peripheral devices can be centrally managed and monitored from a remote server or PC via an IP address.

USB Home Network Devices

Wi-Fi and 802.11
802.11 and Wi-Fi are often used interchangeably.

|Protocol |Frequency |Throughput (Typ)|Data Rate (Max) |Range ( Indoor)|
Legacy //2.4 GHz //0.9 Mbit/s //2 Mbit/s //~20 Meters
802.11a //5 GHz //23 Mbit/s //54 Mbit/s // ~35 Meters
802.11b // 2.4 GHz //4.3 Mbit/s //11 Mbit/s //~38 Meters
802.11g //2.4 GHz //19 Mbit/s //54 Mbit/s // ~38 Meters
802.11n //2.4 GHz/5 GHz //74 Mbit/s //248 Mbit/s// ~70 Meters
802.11y //3.7 GHz //23 Mbit/s// 54 Mbit/s// ~50 Meters

Wi-fi and 802.11 (Home Wireless Network)

ZyXEL Introduces Dual Band Wireless Router: P-335U

* Dual Band Wireless Access
The P-335U provides high speed 802.11g and 802.11a wireless connection. In addition to 802.11g, the P-335U supports the 802.11a band to provide high speed and transmission quality to bandwidth sensitive applications (such as video/audio streaming).

*Media Bandwidth Management
With  exclusive Media Bandwidth Management v2 (MBM v2), the P-335U provides the most comprehensive way to smartly manage your limited bandwidth for multimedia applications.

*Firewall Security

*Sharing Internet Connectivity and Printing Resource
And a built-in USB print server allows you to share a printer on the network without leaving a host PC on. With four auto-sensing, switched LAN ports and Network Address Translation (NAT) routing, as many as home LAN users can access one broadband connection and share printing resource at the same time.
More…

Wireless router for home network

Full list of default Router Admin Passwords and Default Router IP Addresses:

Different routers have deferent manufacturer default settings, including default router IP address, default admin (administrator) password.

Some times, we need to reset the router to factory default setting and configuration, here is a full list of default Router Admin Passwords and Default Router IP Addresses.

Router Configuration and settings

Static IP address: How to assign a static IP to your local computer in your home network

To find out What is IP address/Public IP address/Private IP address, please check :” What is IP Address”

In a typical Home/office Network, you always have a router, which manage the IP addresses assignment via DHCP. When your computer is powered on, the computer requests home network router for an IP addresses, Router then assigns a private IP addresses to the computers or network device which need IP address. But remember, this IP address is private and also dynamic, that means, if your computer is restarted again, it may get another different IP, the IP for same computer is changed every time. (Sure you can configure some routers to assign the same IP to same computer by remembering the computer’s MAC address, that is , router only assign a specific IP to a computer with specific MAC address, MAC address is unique to every computer and nerve changes, in this way, your computer can have a static local private IP address).

For general use, getting dynamic IP address from router via DHCP is the easiest way, because router and computer default configurations work in this way, you do not need to configure your router and computers.But in some situation, for example, you need to run some kind of server within your home LAN,some P2P application etc, you must have a static IP for your computer.

To set a static IP address for your computer:

Start->Settings->Open the control panel->open Network Connections, right-click the “Local Area and chose “Properties”, then (in the “general” tab) select “Internet Protocol(TCP/IP)” and click the “Properties” button. Check the “Use the Following IP address” checkbox and enter your desired IP address : for example here : 192.168.1.8 , then click OK, after you restart your computer, your computer will always has this static IP address unchanged.

Also you can get a static public IP address from your ISP which always costs some money on top of your Internet connection service fee.

Static IP address of Home Network

How to set up Home (web) Server with Dynamic DNS (Dynamic IP address ) in Home/Office LAN

To answer this question, we have to know what is DNS first.

The Domain Name System, or DNS is used to resolve human-readable hostnames into IP addresses, such as resolving a domain name www.homeofficenetwork.net to an IP 208.109.181.77 (this is the web host IP address of this web site), DNS is used whenever you resolve a hostname, whether you are visiting a website, accessing an FTP server, sending email, or any other Internet service.

For example, from your computer’s “Command Prompt” window, type: ping www.yahoo.com and hit enter ,you will get “Reply from 69.147.114.210: bytes=32 time=25ms TTL=53″, here DNS resolved “www.yahoo.com” to the IP address of Yahoo’s web server 69.147.114.210, if you launch your browser and put IP : 69.147.114.210 to the address box, you will also come to yahoo’s home page. You can remember domain name , but you can not remember the IP address. That’s why DNS is very important.
A web server needs to have a static IP address (fixed IP address) to let outside world to access it. Just like your phone number is a fixed number, if your number is keep changing, so no body can reach you. Static IP addresses are typically not provided to residential broadband customers or ISPs will charge a price for a static IP.

Dynamic DNS is a service which lets you create a domain name that will map to your dynamic IP address so that you can run a home server without having a static IP address. You need to install a client that would constantly monitor your external “routable” address, then update the Dynamic DNS servers so that the same domain name is always pointing to your server’s current IP. Nowadays many new routers support Dynamic DNS client software on the router itself. You just need to set your Dynamic DNS account information into the router and router will communicate with Dynamic DNS service provider and keep the IP updated automatically.

There are many Dynamic DNS service providers (some are free services , some are paid servcies), like : DYNDNS.com and TZO.com

The following routers are compatible with DYNDNS.com

* Linksys Routers:
WRT54G wireless router.
BEFSX41 - VPN Endpoint Router
WRT54G and WRT54GL - Wireless Gateway/Router
WRT54G v5 - Wireless Gateway/Router

* D-Link DIR-655

FVS338 - ProSafe VPN Firewall 50
FVX538 - ProSafe VPN Firewall 200
FVS124G - ProSafe Gigabit VPN Firewall 25

Form more help and information, please check the router user manuals, toz.com and dyndns.com

Router Set up with Dynamic DNS

What is Wi-Fi and Wireless Router ?

Wi-Fi is a wireless to improve the interoperability of wireless local area network products based on the IEEE 802.11 standards. Common applications for Wi-Fi include Internet and VoIP phone access, gaming, and network connectivity for consumer electronics such as televisions, DVD players, and digital cameras.Wi-Fi allows LANs to be deployed without cabling for client devices, typically reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs.

Many consumer devices use Wi-Fi. Amongst others, personal computers can network to each other and connect to the Internet, mobile computers can connect to the Internet from any Wi-Fi hotspot, and digital cameras can transfer images wirelessly.

Routers which incorporate a DSL or cable modem and a Wi-Fi access point are often used in homes and other premises, and provide Internet access and internetworking to all devices connected wirelessly or by cable into them,

With a Wi-Fi (Wireless) router Wi-Fi enabled computers , Network devices, you can set your Wireless Home Network and Office Network.

Wi-Fi and Wireless Home Router

Serial to Ethernet :

Nowadays, we still have many legacy serial equipped machines in operations. How can we manage these devices remotely though Ethernet or Internet ? There are some network devices which allow you connect legacy serial equipped machines to your Ethernet LAN or WAN. Serial data from devices in the furthest corners of your plant show up on your office PC as if they were right next door. read more on Serial to Ethernet.

Network tools and devices

What is Managed Switch ?

With a managed switch, you can control every individual ports of the switch. For exmple you can turn on or turn off the ports, you can set the port’s link speed, duplex setting etc. So people can not directly connect to  your LAN through one of the available ports, this makes your LAN more secure.

You can also configure the ports associate with a MAC address, only the computer with this MAC address can connect to this port and connect to your LAN. You can also set the ports with deferent priorities, bandwidth limit, monitor port traffic etc.

VLANS (Virtual LANS) are a popular option. This allows you to set a broadcast domain on certain ports, so that broadcast traffic isn’t passed on to the other ports. This can also isolate machines from each other for security purposes.

Managed and undamaged Switch