Difference between Hub and Switch

Difference between Hub and Switch 

Network devices, or networking hardware, are physical devices that are required for communication and interaction between hardware on a TCP/IP network.

Here is the common network device list:

·        Hub

·        Switch

·        Router

·        Bridge

·        Gateway

·        Modem

·        Repeater

·        Access Point

In 2006 The Network Hub is invented at Vancouver, British Columbia, Canada. A hub is a device that connects multiple Ethernet devices on one network and makes them act together as a single network. A hub does not gather information and input in one port results as an output in all ports on the network. A switch is a networking device that performs the same job as the hub but are considered as a more intelligent hub as it gathers information about the data packets it receives and forwards it to only the network that it was intended for. A Hub is a layer-1 device and operates only in the physical network of the OSI Model.

Hubs and switches are devices that are used in data networking on the internet. These devices are used in order to connect two or more networking ports in order to transfer data along the connection. Though the primary job of hubs and switches are the same, to forward data to different networks, they work in different ways.

A hub, also known as Ethernet hub, active hub, network hub, repeater hub or multiport repeater, is a device that connects multiple Ethernet devices on one network and makes them act together as a single network. A hub has multiple input/output (I/O) ports, in which an input in one port results in it being an output in all the other ports, except the port where it was input. In layman’s terms, a hub connects many networks into one, where a data packet that is sent by one networks, is copied and pasted to all network ports, making it so that every port can see that data packet. A hub works on the physical layer or layer 1 of the Open Systems Interconnection (OSI) model. It also works as a data collision detector, sending a jamming signal to all ports if it detects collisions at one port.

It is a simple device that does not examine the data it receives or sends, while just duplicating the data and making it visible for all. The receiving port that has to decide if the data packet is actually intended for it by checking the address on the packet, before passing it on further. Since hubs only have one collision domain, constant collisions occur. Unnecessary traffic is sent to all devices on the network. Originally hubs were popular due to the high price of switches, but switches are not so expensive these days. Hubs are slowly becoming obsolete in many practices, but are still used in special circumstances.

A switch is a networking device that performs the same job as the hub; it connects network segments or devices making them act as a single network. Switches are commonly referred to as a multi-port network bridge that process and routes data on a data link layer or layer of the OSI model. Switches can also process data at the network layer (layer 3) or higher layers and are known as multilayer switches.

Switches are considered as a more intelligent hub as it gathers information about the data packets it receives and forwards it to only the network that it was intended for. When a switch receives a data packet, it examines the data address, the sender and the receiver and stores the memory, after which it then sends the data to the device that the data is meant for.

Most modern Ethernet Local Area Networks (LANs) operate on switches. Small offices and residential devices commonly use single layer switch, while bigger applications require multilayer switches. The switches use a bridge or a router in order to split a larger collision domain to smaller collision domains, resulting in lesser collisions.  Each port has an individual collision domain, allowing computers to maintain dedicated bandwidth.

	Hub	Switch
Definition	A hub is a connection point for different segments of a LAN. It contains multiple ports and when it receives a packet of information at one port, it copies this packet to all segments of the LAN so that it can be viewed by all ports.	A switch is multi-port networking device that connects network devices together. A switch operates at the data link layer (layer 2) of the OSI model. A switch filters and then forwards data packets between networks.
Layer	Physical Layer (Layer 1)	Data Link Layer (Layer 2)
Spanning-Tree	No Spanning-Tree	It allows many Spanning-Trees to take place.
Type of Transmission	Broadcast	Broadcast, Uni-cast & Multicast.
Table	No MAC table. Hubs cannot learn MAC address.	Stores MAC address and maintains address.
Used in	LAN (Local Area Networks)	LAN (Local Area Networks)
No of Ports	4	24-48 depending on type of switch.
Collision	Occurs	No collision occurs
Collision Domain	One collision domain	Every port has its own collision domain.
Transmission Mode	Half duplex	Full duplex

Types of Hub

There are three types of the hub that are given below:

1.  Passive Hub

2.  Active Hub

3.  Intelligent Hub

Passive Hub: The passive hubs are the connection point for wires that helps to make the physical network. It is capable of determining the bugs and faulty hardware. Simply, it accepts the packet over a port and circulates it to all ports. It includes connectors (10base-2 port and RJ-45) that can be applied as a standard in your network. This connector is connected to all local area network (LAN) devices. Additionally, the advanced passive hubs have AUI ports, which are connected as the transceiver according to the network design.

Active Hub: As compared to a passive hub, it includes some additional features. It is able to monitor the data sent to the connected devices. It plays an important role between the connected devices with the help of store technology, where it checks the data to be sent and decides which packet to send first.

It has the ability to fix the damaged packets when packets are sending, and also able to hold the direction of the rest of the packets and distribute them. If a port receives a weak signal, but still it is readable, then the active hub reconstructs the weak signal into a stronger signal before its sending to other ports. It can boost the signal if any connecting device is not working in the network. Therefore, it helps to make the continuity of services in LAN.

Intelligent Hub: It is a little smarter than passive and active hubs. These hubs have some kinds of management software that help to analyze the problem in the network and resolve them. It is beneficial to expend the business in networking; the management can assign users that help to work more quickly and share a common pool efficiently by using intelligent hubs. However, it offers better performance for the local area network. Furthermore, with any physical device, if any problem is detected, it is able to detect this problem easily.

The important applications of a hub are given below:

·        Hub is used to create small home networks.

·        It is used for network monitoring.

·        They are also used in organizations to provide connectivity.

·        It can be used to create a device that is available thought out of the network.

Advantages of Hub

1. It provides support for different types of Network Media.

2.  It can be used by anyone as it is very cheap.

3.  It can easily connect many different media types.

4.  The use of a hub does not impact on the network performance.

5.  Additionally, it can expand the total distance of the network.

Disadvantages of Hub

1. It has no ability to choose the best path of the network.

2.  It does not include mechanisms such as collision detection.

3.  It does not operate in full-duplex mode and cannot be divided into the Segment.

4.  It cannot reduce the network traffic as it has no mechanism.

5.  It is not able to filter the information as it transmits packets to all the connected segments.

6.  Furthermore, it is not capable of connecting various network architectures like a ring, token, and ethernet, and more.

Configure Router as Switch

How to configure router as switch?
Most likely you will ask this question if you plan to expand you home network, and you have only extra Ethernet router but not switch. At the same time you try to make use this extra router if possible without paying more on extra switch. Well… It’s pretty simple to get it done, keep on reading.

As you can see from 2 examples below, we can use second Ethernet router to expand existing wireless network or Ethernet home network, so that you can connect more computers to your network. Please note that first and second routers must be located on same network, because the second router just acts as a switch, not router anymore.

Ok. Let’s start to configure second router as switch.

1) Connect first router’s LAN port to second router’s LAN port by using a crossover cable. If one of the routers supports auto MDI/MDI-X feature, you can use either straight or crossover cable. Remember, don’t make any connection to second router’s WAN or Internet port.

2) Ok. Now assuming your first router's LAN IP is 192.168.1.1 with subnet mask 255.255.255.0, and then this will act as gateway for entire network (including the computers that connect to second router). If you would like to enable DHCP, then just enable the DHCP setting on first router and it will act as DHCP server for entire network (you don't need to enable DHCP on second router anymore). As an example, you can enable DHCP with IP range 192.168.1.2-250, subnet mask 255.255.255.0, gateway 192.168.1.1, DNS servers 208.67.222.222 and 208.67.220.220 on first router.

3) After talking about first router's configuration, proceed to log on to second router’s configuration page, then give this router an IP by configuring an IP and subnet mask under LAN setting. The IP that you configure should be located on subnet same with first router's subnet and this IP is not being used by any other device. If you have configured first router’s LAN IP and DHCP setting as shown in step 2 above, you can easily configure second router with LAN IP 192.168.1.251, 192.168.1.252 or 192.168.1.253 and subnet mask 255.255.255.0.

4) After that, don’t enable DHCP or any other settings on second router. If you have enabled DHCP or other settings, disable them. Finally SAVE all the settings. And now your have completed your mission of making second router as switch.

5) If you have computer that is configured to obtain IP automatically, connect it to other LAN port of this new "network switch", then it should be able connect to network, ping router IP and access to internet.

How To Setup Two or More Routers Together

One of the most common issues people encounter is when they have more than one router hooked up. Sometimes people don't realize their modem is also a router (Such as DSL) and other times people hook up an extra router to use things their router/modem doesn't have, such as wireless.

So now with 2 or more routers hooked up people start to realize port forwarding & port triggering isn't working. This is because they are only setting up the port forwarding or triggering in one router, which is what they should be doing! Now let me explain, no one wants to setup port forwarding & triggering rules in two or more routers, they should only need to do it in one, making things simple. But you may ask "If I have more than one router how can I keep it simple?" The answer: DMZ

First off DMZ is supported by nearly every router/modem out there. What DMZ does is allow you to tell the router to forward all incoming connections to a single IP address. So in this case we will setup DMZ in the first router to point to the second router. Now all incoming connections are sent to the 2nd router and thus your port forwarding & triggering will work again.

So here is a quick example. I log into router 1 and go to the DMZ settings and put the WAN IP address of the 2nd router there. Now router 1 is out of the way for port forwarding and triggering as all incoming connections are now being forwarded to router 2. Now in router 2 I can setup my port forwarding & triggering rules just like normal.

So here is a quick step by step.
Step 1. Login into your Router
Step 2. Find the status page that shows the WAN/Internet IP address and write it down. (The Gateway IP will be the IP needed to log into the first router/modem.)
Step 3. Log into the first router/modem now.
Step 4. Find the DMZ page
Step 5. Enter the IP you wrote down into the DMZ page and enable DMZ.
Step 6. Save and you’re done.

Quick Tip: You should setup a static WAN IP address for router 2. If you leave it on DHCP the IP could change thus breaking the DMZ and of course breaking the port forwarding & triggering. This doesn't happen very often, but it is always a possibility.

If you want to Setup 3 routers at home. Here is my plan to setup. Please let me know if it make sense.

1.    SMC. It is a modern with router. It locates in the first floor, Rogers cable connected to this router. It is the main router to connect outside. I turned off the wireless on the router. It has 4 ports connected to SMC all with wires. First one connect to D-615(second router) Second one connect to D-815(third router) Third one connect to WD Mybook live(NAS HHD) Fourth one connect to TV player

2.    DLink 615. It is a wireless router. It located in the first floor as well, but close to bedroom. It has 4 ports, but I only use 3 of them connected to PC. Also there are wireless device need connect to this router as well.

3.    DLInk 815. It is a wireless router. It located in the second floor. It connected with 3 PCs and also accept wireless connection. The signal in second floor is very weak if using D-615 wireless connection.

I setup the SMC to 192.168.0.1 with DHCP, D-615 to 192.168.2.1 with DHCP and D-815 to 192.168.1.1. I cannot get rid of the second router, since SMC doesn't have enough wired port. And I need to D-815 because the signal problem. Wondering if this gonna work? Thanks.