Switches require high room temperature and environment. The switch needs to operate in a constant temperature and clean environment because of its large number of users, high energy consumption and considerable heat emission. If the room temperature is higher, it will be difficult for the machine to heat, which will cause the change of the parameters of the switch components, and the equipment will be damaged in serious cases. If the room is too dry, static electricity will occur, which threatens the safety of the switch.
According to the regulations, the temperature and humidity of the machine room need to be measured strictly by a thermometer. When necessary, air conditioning and humidifier can be installed to adjust the temperature and humidity. Fire prevention and dust prevention measures should also be taken.
Professional switchboard maintenance personnel are on duty every day to check the functions of software and hardware. Besides recording the environmental temperature and humidity in the room, they should check whether the input voltage and output voltage, current, frequency and other indicators are within the normal range of operation, test whether the signals of various sound sources are normal, and check the spare parts. Whether spare parts, tools and instruments are complete or not, fully understand the working conditions of each system, and make good records and checks. Periodically do a good job in the overall anti-virus work of servers and maintenance terminals to ensure the safe operation of the servers.
Preventive maintenance is to collect all kinds of data needed by switches by means of checking, measuring and spot checking, and to classify and analyze the data professionally, so as to put forward specific methods and measures for eliminating hidden dangers of switches. In peacetime maintenance of exchanges, preventive maintenance should be taken as the main task, and preventive measures should be taken in the near future.
Professional switch operators are required to use terminals in strict accordance with the operating manual. First, they should check the software configuration of the system or the software of the system, avoid executing wrong orders in their daily work, and strictly check whether the I/O equipment is in normal condition, especially the inspection of floppy disk drives. Correct the wrong data in time. Software tapes brought by switching equipment must be properly kept. If the switching system is paralyzed, they can be reinstalled and used. In daily work, professional maintenance personnel are good at discovering potential faults of equipment, finding out the main causes of possible faults and eliminating hidden dangers.
In order to ensure the scientific and institutionalized management of the switchboard room, various rules and regulations, duty system, spare parts management system of the room should be formulated, the original data recording system should be done well, the room should be kept clean and sanitary, and the work of safety and confidentiality should be done well. The maintenance authority of switch operators should be set reasonably and effectively to avoid system failure caused by human factors. For the deletion and modification of switch data, the data must be backed up first in order to avoid losing the original data, which brings inconvenience to the daily data recording work of the switch.
Switches need professional personnel for care and maintenance, often wipe the dust, to prevent ash into the inside of the switch, resulting in short circuit, causing system failure. It is not allowed to replace circuit boards and components without reason, nor to disassemble the switch privately. If the indicator light of the switch is long on, it indicates that the switch has malfunction, it should cut off the power supply, stop using it and give it to professional personnel for maintenance.
Because the faults of switches are various, some of them are obvious, they can be identified at a glance, processed and maintained, and some of them are not so clear, so specific problems need to be analyzed.
MORE DETAILS:https://network-exp.com/collections/all-switch/products/copy-of-h3c-ls-5820x-28c-h3-ethernet-switch
]]>1. Fault phenomenon: The whole network works normally, but individual machines can not communicate normally.
2. Cause of failure: This is the most common breakdown of switch. If the optical fiber plug or RJ-45 port is dirty, it may lead to port pollution and can not communicate normally. Also, many people usually like live plug-in and pull-out connectors, which seems not to be inappropriate in theory, but in fact, often this will inadvertently increase the incidence of port failures; careless handling may also lead to physical damage to the port; the purchase of large crystal head size, when inserted into the switch, it is also easy to break. Bad port. In addition, if a twisted pair connected to the port is exposed outdoors, in case the cable is struck by lightning, the connected switch port will be damaged.
3. Solution: In general, the port fault is the damage of individual ports. First, check the computer in question. After eliminating the fault of the computer connected by the port, we can judge whether the port problem is or not by replacing the connected port. If the problem can be solved after replacing the port, we can further determine what the port is. Species. When the power is off, clean the port with alcohol cotton ball. If the port is damaged, the port can only be replaced. In addition, whether it is the optical fiber port or the RJ-45 port of twisted pair, we must be careful when plugging and unplugging the joint. It is recommended that the plugging and unplugging should not be operated live.
1. Fault phenomenon: There is a computer room where a part of the computer can not access the server.
2. Fault reason: The switch is generally composed of the main circuit board and the power supply circuit board, which are the two parts of the fault. The main factors that cause the circuit board to not work properly are: damaged components or bad substrates on the circuit board, inappropriate hardware injection and hardware updating, and inappropriate type of circuit board due to compatibility problems.
3. Solution: First, determine whether there is a problem in the main circuit board or the power supply circuit board. First, check the power supply part and use the universal meter to measure the power supply when the load of the main circuit board is removed to see whether the measured indicators are normal or not. If not, switch to an AT power supply, input the power to the main circuit board, and exchange. The indicator lamp on the front panel of the switch restores its normal brightness and color, and the computer connected to the switch visits each other normally, indicating that there is a problem with the power supply circuit board. If the above operation is invalid, the problem should appear on the main circuit board.
1. Fault phenomenon: After switching on the switch, the switch did not work properly, and found that the POWER indicator on the panel did not turn on, and the fan did not turn.
2. Causes of failure: This kind of failure is usually due to the instability of external power supply environment, or the aging of power supply lines, or the power supply damage or fan stop caused by lightning strike, which results in the switch not working properly. It is also possible that other parts of the switch are damaged due to power supply.
3. Solution: This kind of problem is easy to find and solve. When this kind of fault occurs, first check the power supply system to see if there is any current in the power supply socket and if the voltage is normal. If the power supply is normal, it is necessary to check whether the power cord has been damaged or loosened. If the power cord is damaged, replace one and re-insert it if it is loosened. If the problem has not been solved, it should be left in the switch power supply or other parts of the machine damaged.
1.1. What is VLAN?
VLAN (Virtual LAN), translated into Chinese as "虚拟局域网". LAN can be a network of a few household computers or an enterprise network of hundreds of computers. VLAN refers to a network partitioned by a router, that is, a broadcast domain.
Let's review the concept of broadcast domain first. Broadcast domain refers to the range that the broadcast frame (the target MAC address is all 1) can pass to, that is, the range that can communicate directly. Strictly speaking, it is not only broadcast frames, but also multicast frames and unicast frames with unknown targets can travel freely in the same broadcast domain.
Originally, Layer 2 switch can only construct a single broadcast domain, but after using VLAN function, it can divide the network into multiple broadcast domains.
Then, why do we need to divide the broadcast domain? That is because if there is only one broadcast domain, it may affect the overall transmission performance of the network. For specific reasons, please refer to the attached drawings for further understanding.
In the figure, it is a network consisting of five Layer 2 switches (switches 1-5) connected with a large number of clients. Suppose that computer A needs to communicate with computer B at this time. In Ethernet-based communication, the target MAC address must be specified in the data frame in order to communicate normally, so computer A must first broadcast "ARP Request" information to try to obtain the MAC address of computer B.
Switch 1 receives the broadcast frame (ARP request) and forwards it to all ports except the receiving port, namely Flooding. Next, switch 2 will also Flooding when it receives a broadcast frame. Switches 3, 4, 5 also have Flooding. Finally, ARP requests are forwarded to all clients in the same network.
Please note that this ARP request was originally sent to obtain the MAC address of computer B. That is to say, as long as computer B can receive everything. But in fact, data frames are transmitted throughout the network, resulting in all computers receiving it. In this way, on the one hand, broadcast information consumes the overall bandwidth of the network, on the other hand, the computer receiving broadcast information also consumes a part of CPU time to process it. It causes a lot of unnecessary consumption of network bandwidth and CPU computing power.
Read here, you may ask: is radio information really so frequent?
The answer is: Yes! In fact, broadcast frames appear very frequently. When using TCP/IP protocol stack to communicate, besides ARP, there may be many other types of broadcast information such as DHCP, RIP and so on.
ARP broadcasting is issued when it needs to communicate with other hosts. When a client requests a DHCP server to assign an IP address, it must broadcast DHCP. When RIP is used as routing protocol, the router broadcasts routing information to other neighboring routers every 30 seconds. Routing protocols other than RIP use multicast to transmit routing information, which is also forwarded by switches. In addition to TCP/IP, NetBEUI, IPX and Apple Talk protocols often require broadcasting. For example, when you double-click on "Network Computer" under Windows, you will send a broadcast (multicast) message. (Except Windows XP... )
In short, the radio is right beside us. Here are some common broadcasting communications:
ARP request: Establish the mapping relationship between IP address and MAC address.
RIP: A routing protocol.
DHCP: Protocol for automatically setting IP addresses.
NetBEUI: A network protocol used under Windows.
IPX: The network protocol used by Novell Netware.
Apple Talk:The network protocol used by Apple's Macintosh computers.
If there is only one broadcast domain in the whole network, once the broadcast message is sent, it will spread all over the network and bring additional burden to the host in the network. Therefore, when designing LAN, we need to pay attention to how to effectively divide the broadcast domain.
When partitioning broadcast domains, routers are generally required. After using the router, the broadcast domain can be divided by the LAN Interface on the router.
However, in general, there are not too many network interfaces on routers, the number of which is about 1-4. With the popularity of broadband connections, broadband routers (or IP sharers) become more common. However, it should be noted that although they have multiple (generally about four) network interfaces on the LAN side, they are actually built-in switches in routers and can not divide broadcasting domains.
Moreover, when using routers to divide broadcasting domain, the number of divisions depends entirely on the number of network interfaces of routers, which makes it impossible for users to divide broadcasting domain freely according to actual needs.
Compared with routers, Layer 2 switches generally have multiple network interfaces. Therefore, if it can be used to divide the broadcast domain, then undoubtedly the flexibility in application will be greatly improved.
VLAN is the technology used to divide broadcasting domain on Layer 2 switch. By using VLAN, we can freely design the composition of broadcast domain and improve the degree of freedom of network design.
After understanding why VLAN is needed, let's look at how switches use VLAN to split broadcast domains.
First, on a Layer 2 switch without any VLAN, any broadcast frame will be forwarded to all other ports except the receiving port (Flooding). For example, when computer A sends broadcast information, it is forwarded to ports 2, 3 and 4.
At this time, if two VLANs are generated on the switch, port 1 and 2 belong to the red VLAN, port 3 and 4 belong to the blue VLAN. If the broadcast frame is sent from A, the switch will only forward it to other ports belonging to the same VLAN - that is, port 2 belonging to the same red VLAN, and not to the ports belonging to the blue VLAN.
Similarly, when C sends broadcast information, it will only be forwarded to other ports belonging to blue VLAN, but not to ports belonging to red VLAN.
In this way, VLAN divides the broadcast domain by limiting the range of broadcast frame forwarding. For illustration purposes, the above figure identifies different VLANs in red and blue. In practice, it is distinguished by "VLAN ID".
If we want to describe VLAN more intuitively, we can understand it as dividing a switch into several switches logically. Generating red and blue VLANs on one switch can also be regarded as replacing one switch with one red, one blue and two virtual switches.
When a new VLAN is generated outside the red and blue VLANs, it can be imagined that a new switch is added.
However, the logical switches generated by VLAN are not interconnected. Therefore, after setting up VLAN on the switch, if no other processing is done, VLAN can not communicate with each other.
Clearly connected to the same switch, but unable to communicate - this fact may be unacceptable. But it is not only the easy-to-use feature of VLAN, but also the reason why VLAN is difficult to understand.
So what should we do when we need to communicate between different VLANs?
Please recall once again that VLAN is a broadcast domain. Generally, the two broadcast domains are connected by routers, and the data packets between broadcast domains are relayed by routers. Therefore, communication between VLANs also requires routers to provide relay services, which is called "inter-VLAN routing".
Routing between VLANs can use either ordinary routers or three-tier switches. The specific content will be elaborated when the opportunity arises. Here I hope you will remember that the routing function is needed when different VLANs communicate with each other.
Switch ports can be divided into the following two types:
Access Link
Trunk Link
Next let's learn the characteristics of these two different ports in turn. First of all, learn "Access Links".
Access links refer to ports that "belong to only one VLAN and only forward data frames to that VLAN". In most cases, access links connect to clients.
Usually the order of setting VLAN is:
Generating VLAN
Setting access links (deciding which VLAN each port belongs to)
The method of setting access links can be fixed in advance or dynamically changed according to the computer connected. The former is called "static VLAN" and the latter is naturally "dynamic VLAN".
3.2.1、Static VLAN
Static VLAN is also called Port Based VLAN. As the name implies, it specifies which VLAN each port belongs to.
Because of the need to specify ports one by one, when the number of computers in the network exceeds a certain number (for example, hundreds), setting operations will become extremely cumbersome. Moreover, every time a client changes the port it connects, it must change the settings of the VLAN that the port belongs to at the same time -- which is obviously not suitable for networks that need to change the topology frequently.
3.2.2、Dynamic VLAN
On the other hand, dynamic VLAN changes the VLAN of the port at any time according to the computer connected to each port. This avoids such operations as changing the settings mentioned above. Dynamic VLAN can be roughly divided into three categories:
VLAN (MAC Based VLAN) Based on MAC Address
Subnet Based VLAN
The main difference between them is that the VLAN to which port belongs is determined according to the information of which layer of OSI reference model.
(1) VLAN based on MAC address determines the port ownership by querying and recording the MAC address of the computer network card connected to the port. Assuming that a MAC address "A" is set to belong to VLAN "10" by the switch, no matter which port the computer with the MAC address "A" is connected to, the port will be divided into VLAN10. When a computer is connected to port 1, port 1 belongs to VLAN10; when a computer is connected to port 2, port 2 belongs to VLAN10.
(2) The VLAN based on subnet determines the VLAN to which the port belongs by the IP address of the connected computer. Unlike VLAN based on MAC address, even if the computer changes its MAC address due to the exchange of network cards or other reasons, as long as its IP address remains unchanged, it can still join the original VLAN.
Therefore, compared with VLAN based on MAC address, it can change the network structure more easily. IP address is the third layer information in OSI reference model, so we can understand that subnet-based VLAN is a method of setting access links in the third layer of OSI.
(3) User-based VLAN decides which VLAN the port belongs to according to the user currently logged in on the computer connected to each port of the switch. The user identification information here is generally the user logged in by the computer operating system, such as the user name used in the Windows domain. These username information belongs to the information above the fourth layer of OSI.
Generally speaking, the higher the level of information used in OSI when deciding which VLAN the port belongs to, the more suitable it is to build a flexible network.
3.2.3、Summary of Access Links
In summary, there are two ways to set access links: static VLAN and dynamic VLAN, in which dynamic VLAN can continue to be subdivided into several sub-categories.
Among them, VLAN based on subnet and VLAN based on user may be implemented by network equipment manufacturer using unique protocol, and compatibility problems may arise between devices of different manufacturer; therefore, when choosing switch, we must pay attention to confirming in advance.
When planning enterprise network, it is very likely to encounter the situation that users belonging to the same department are scattered in different floors of the same building. At this time, it may be necessary to consider how to set up VLAN across multiple switches. Suppose there is a network as shown in the figure below, and you need to set A, C, B, D on different floors to the same VLAN.
At this point, the most critical is "how to connect switch 1 and switch 2?"
The simplest way is naturally to set up a dedicated red and blue VLAN interface on switches 1 and 2 and interconnect them.
However, this approach is not good in terms of scalability and management efficiency. For example, when a new VLAN is built on the basis of the existing network, in order to make the VLAN interoperable, it is necessary to connect new network lines between switches. Longitudinal wiring between floors of buildings is more troublesome, and generally can not be carried out at will by grass-roots managers. Moreover, the more VLAN, the more ports are needed for interconnection between floors (strictly speaking, switches). The inefficient use of switch ports is a waste of resources and limits the expansion of the network.
In order to avoid this inefficient connection, people try to concentrate the interconnected network wires between switches on one, which is called Trunk Link.
Trunk Link refers to a port that can forward communications between multiple different VLANs.
The data frames circulating on the sink link are attached with special information for identifying which VLAN they belong to.
It is possible to support the standard "IE802.1Q" protocol or the unique "ISL" (Inter Switch Link) of Cisco products by aggregating additional VLAN identification information at link time. If switches support these specifications, users can efficiently construct VLANs across multiple switches.
In addition, there are many VLANs in the aggregation link, so the natural load is heavy. Therefore, when setting up aggregation links, there is a prerequisite that the transmission speed of more than 100 Mbps must be supported.
In addition, by default, aggregate links forward all VLAN data that exists on the switch. From another point of view, converge links (ports) can be considered to belong to all VLANs on the switch at the same time. Since it is not likely that all VLAN data need to be forwarded in practice, in order to reduce the load of switches and the waste of bandwidth, we can use user-defined restrictions to interconnect VLANs via aggregate links.
On the convergence link of switches, VLAN spanning multiple switches can be constructed by adding VLAN information to data frames.
The most representative methods of adding VLAN information are:
IEEE802.1Q
ISL
IEEE802.1Q, commonly known as "Dot One Q", is an IEEE-certified protocol for attaching VLAN recognition information to data frames.
Here, please recall the standard format of Ethernet data frames.
The VLAN identification information attached to IEEE802.1Q is located between the "sending source MAC address" and the "Type Field" in the data frame. Specific content is 2 bytes of TPID and 2 bytes of TCI, a total of 4 bytes.
When 4 bytes are added to the data frame, the CRC value will naturally change. At this time, the CRC on the data frame is the value obtained by recalculating the entire data frame including TPID and TCI after inserting them.
When the data frame leaves the sink link, TPID and TCI will be removed, and CRC will be recalculated.
The value of TPID is fixed to 0x8100. The switch uses TPID to determine that the VLAN information based on IEEE802.1Q is added to the data frame. In essence, VLAN ID is 12 bits in TCI. Since there are 12 bits in total, a maximum of 4096 VLANs can be identified.
Additional VLAN information based on IEEE802.1Q is like tags attached when delivering items. Therefore, it is also called "Tagging VLAN".
SL is a protocol similar to IEEE802.1Q supported by Cisco products for attaching VLAN information to aggregate links.
After using ISL, each data frame header will be added 26 bytes of "ISL Header" and the 4 bytes CRC value will be obtained by computing the whole data frame including ISL header on the frame tail band. In other words, a total of 30 bytes of information has been added.
In the ISL environment, when the data frame leaves the sink link, simply remove the ISL header and the new CRC. Since the original data frame and its CRC are completely preserved, there is no need to recalculate the CRC.
ISL is like wrapping the original data frame with ISL header and new CRC, so it is also called "Encapsulated VLAN".
It should be noted that neither the "Tagging VLAN" of IEEE802.1Q nor the "Encapsulated VLAN" of ISL are very strict terms. In different books and reference materials, the above words may be used in a mixed way, so we need to pay more attention to them in learning.
Because ISL is a unique protocol of Cisco, it can only be used for interconnection between Cisco network devices.
Hand-held Optical Time Domain Reflectometer of NK2000 Series is a newly hand-held and intelligent communication measuring device in accordance with the test of Optical fiber and Communication System. The product is used to measure the parameters like optical fibers, length of the optical fiber, loss, following quality and the like. It can quickly and accurately position the case point and fault point of the optical fiber link. It can be widely used in the engineering construction, route maintenance and urgent repair of the Optical fiber and Communication System. It can also be used in optical fiber and optical cable development as well as production measurement. The product can effectively do help to the installation and construction of the optical fiber network, the following speedy and effective maintenance and the troubleshooting test.
NK2000 is sturdy and durable with a novel and attractive appearance. The most succinct operation interface with a simple and intuitive style is specially designed for the domestic users. The dual operation mode of press key and touch screen effectively simplifies the application of the users. You can obtain the test result by the one-click analysis and the events will appear on the main interface in a list form with the information of event number, type, location (distance), loss, reflex, gradient of the events (attenuation) and total loss. Intelligent power management mode is employed to the machine. The working duration of the machine can be more than 10 hours with the high-capacity lithium battery.
OTDR of NK2000 Serious is equipped with the most succinct operation interface, which is specially designed for the users. With a simple and intuitive style, there are only 6 operation menus on the optimized interface. The operation is so simple that it is easy to acquire it without professional training. The unique dual operation mode of press key and touch screen among the similar products in the industry effectively simplifies the application of the users.
OTDR of NK2000 Serious is equipped with shortcut key of trace analysis, which can quickly and accurately find the event point or fault point and its position information of the trace tested. Then it will list all the information in the circuits, which do great help to the maintainers, improving the testing efficiency as well as ignoring the cumbersome background.
The tiny test dead zone and large dynamic range of NK2000 OTDR can meet both the testing of optical fiber wire jumper and the long-distance testing field . It is of highest cost performance!
When OTDR is testing optical fiber link, the result will be inaccurate if there is communication optical signal in the optical fiber. Communication optical signal may even damage the optical receiver of the machine. NK2000 OTDR can automatically monitor the communication optical signal in the optical fiber. Once the optical signal is detected, the connector will give an alarm, which provides the machine with a fastest and timeliest protection.
NK2000 OTDR built-in high-power visible red light fault location function can find the short distance optical fiber link breakpoint or the position of a big loss point conveniently and directly. Combined with OTDR function, it can enable a seamless monitoring of the chain and test, so that the maintainer can take measures in time and save time.
The universal light interface equipped to NK2000 OTDR is easy to be replaced and cleaned. It can enable tests for many kinds of interfaces such as FC, SC and ST.
The simulation software can analyze, edit and derive the data stored by instruments, and it can generate the complete and professional OTDR report in a convenient and fast way.
Model Item |
NK2000 Series |
|||
S1 |
S2 |
S3 |
M1 |
|
Optical fiber type |
Single-mode |
Multi-mode |
||
Central wavelength (nm) |
1310/1550
|
850/1300
|
||
Maximum dynamic range(dB) |
28/26 |
36/35 |
40/39 |
22/28 |
Event dead zone(m) |
1.5 |
1.5 |
1.5 |
3 |
Attenuation dead zone(m) |
6 |
6 |
6 |
6 |
Display screen type |
3.5 inch color LCD, operation of the touch screen |
|||
Optical interface |
FC/UPC (can be interchanged to SC or ST) |
|||
Test range (km) |
0.5、1、2、4、8、16、32、64、128、256 |
|||
Pulse width(ns) |
5、30、50、100、275、500、1000、5000、10000 |
|||
Ranging accuracy(m) |
± (1m+ sample interval +0.005%×distance) |
|||
Attenuation measurement (dB/dB) |
±0.05 |
|||
Reflection measurement (dB) |
±5 |
|||
Data storage |
≥2000 testing curves |
|||
Communication interface |
USB |
|||
Visible red light source |
||||
Output power |
≥2mW |
|||
Testing distance |
≥5km |
|||
Environmental adaptability |
||||
Power supply mode |
AC/DC adapter: alternating current:100V~240V (1.8A), 50/60Hz direct current: 19V±1V(2A) Internal lithium ion battery groups: 7.4V,5200mAh |
|||
Working duration of the battery |
≥10hours |
|||
Working temperature |
-5℃~50℃ |
|||
Preserve temperature |
-20℃~70℃ |
|||
Weight |
≤1kg |
|||
Volume |
208mm×110mm×56mm |
Standard Configuration
Number |
Name |
Quantity |
1 |
NK2000 OTDR |
1 |
2 |
Power line |
1 |
3 |
AC/DC power adapter |
1 |
4 |
Product qualification certificate |
1 |
5 |
User manual |
1 |
6 |
Disk (including simulation analysis software) |
1 |
7 |
Special bag for the instruments |
1 |
Note: The standard configuration of OTDR interface type is FC/UPC. The type of FC/APC is optional.
Click to buy: https://network-exp.com/products/nk2000-smart-series-hand-held-optical-time-domain-reflectometer?_pos=1&_sid=f520fce33&_ss=r]]>An unmanaged switch lets the network devices talk to each other. Traffic moves across the switch unregulated. Everything is given the same priority.
A managed switch allows the same flow of data, except that it lets the network manager to configure, manage, and monitor the LAN. The network administrator can control which devices take priority, can change configurations if the network has slowdowns, and see the health of the network or any device.
Imagine one of those old telephone switchboards where the operator would connect each call. An unmanaged ethernet switch is like an operator who finds out where a call is going and connects it. A manager switch would be an operator who decides which of the two calls trying to go to the same person is more important.
Managed switches also use certain protocols to make managing the network easier. Simple Network Management Protocol (SNMP) is a built-in program that monitors a network’s health, makes changes as needed, and notifies the administrator if there’s a problem. It displays the information on a simple-to-use dashboard that makes the management of the network simple and intuitive.
Do I need a managed switch?
For most businesses, a managed switch will be more effective. Rather than causing “traffic jams” at the switch, it will monitor traffic and lets you manage which device, and therefore, which data is more important. For example, you might put your workstation as the highest priority, over the printer. Since your workstation is where the most important data is being exchanged, it makes sense to prioritize it that way.
With an unmanaged switch, the traffic is unregulated. For businesses that have a lot of data moving from one device to another especially from any device to and from the internet, an unmanaged switch can slow things down.
If there are only a few devices, use an unmanaged switch. As soon as your network has grown to several devices and workstations, you need a managed switch.
Smart Switches - The Middle Ground
Between the unmanaged switch that has no data restrictions, and the managed switch that lets you control almost everything, is the smart switch. While you can’t change as many configurations as a managed switch, you can change some settings.
The smart switch is less intimidating that a fully managed switch, but it allows for enough customization for a medium-sized network.
Which switch? A couple of rules for deciding
If you’re not sure which switch you need, here is a brief guide:
20 or fewer active users - An unmanaged switch should be fine. If you’re working in a standard office, with word processing, internet access, and printing, an unmanaged switch will work.
20 to 100 active users - A smart switch is a wise choice; it allows you enough controls to direct traffic well and keep everything flowing nicely. The only exception might be a firm that moves a lot of data from place to place, like a video company.
100 or more users - A managed switch is the only way to ensure that priority traffic is given the ‘right of way’ to keep traffic flowing well. This will also come with a network that is relatively large as well.
A smaller company that expects to grow might look to buy a switch that is a level above its present needs. Having scalability in your switch can prevent a larger expense amid buying and installing new workstations, staff, etc.
How numbers of ports (8, 16, 32, 48) affect the capability of switch
The first thing anyone notices about ethernet switches is the number of ports. This can range from four to 48. The more ports, the more devices the switch can control.
Deciding how many ports you need is a matter of knowing how many devices you have. One port per device is how you will decide. That said, it’s wise to plan. If you buy an 8-port Ethernet switch this week and fill it next week, you will be paying for a new switch soon. On the other hand, buying a 32-port switch when you only have five devices to hook to it is not only a waste of money, it’s a waste of time. You will spend far longer configuring it than you really need.
For example, the H3C S1850-10P is a 10-port gigabit Ethernet switch. It’s ideal for a small business that wants to have the ability to control their traffic. By contrast, the H3C S5560S-SI Layer 3 series provides models that are 24 or 48 ports. Both offer granular controls, but larger switches will consume more energy and require more cooling.
In short, as was noted above, get ahead of your growth, but don’t go to crazy. You might end up with something you can never fill and won’t need.
]]>This list offers unmanaged and managed switches. The difference is how much control you’ll need over the devices in your business. Unmanaged switches are “plug-n-play”. You can’t control traffic priorities; it’s all preset. This is fine for home businesses or small businesses. A larger business or one with more traffic might need a managed solution. This allows you to control which devices get priority as traffic flows through the switch.
If you’re unsure, you will do well to get an unmanaged device. The chip inside controls the flow of traffic, so you don’t have to spend a lot of time telling it what to do.
1. Linksys LGS116P (unmanaged)
https://www.linksys.com/us/p/P-LGS116P/
Linksys is one of the world’s leading computer peripherals manufacturers, especially for consumers and small business. The LGS116P has 16-port switches. Because the cooling vents are on the sides, it can be laid flat on a shelf or wall-mounted. It relies on passive cooling, so a fan or two might be needed to keep it cool.
There are 16 Gigabit 10/100/1000 Ethernet ports. The first eight have PoE+ support. These ports allow you to connect compatible devices, transfer data, and receive power over the Ethernet. The total power budget is 80 W.
The LGS116P is equipped with a Marvell 88E1685LKJ2 chipset. Since this gives you 2 gigabits per port, you have a total bandwidth of 32 gigabits.
Linksys makes this device very easy to set up. Find a spot for it, plug it into a power source, and then plug in your devices.
The LInksys offers several features that make it easier to use. It has Quality of Service Traffic Prioritization (QoS) which guarantees that certain devices, like video and VoIP, are given priority to ensure smooth data streams. It also has PoE prioritization. This mean that if you connect your most important device to port 1, it will always receive priority over the other ports. So while it is an unmanaged device, you do have some control over what device take priority.
The Linksys LGS116P is an ethernet switch for someone who wants to have to do very little except plug it in and connect the devices.
2. Cisco SG112-24-NA (unmanaged)
https://www.amazon.com/SYSTEMS-24-Port-Gigabit-Switch-SG11224NA/dp/B00VPT8XSQ
Cisco is the world’s largest networking company, so it’s no surprise that one of their devices makes the list.
The Cisco SG112-24-NA is an ethernet switch that is great for small businesses and homes. The SG112-24-NA is unique because of its size - 11.0 x 1.7 x 6.7 inches. It’s extremely compact.
Primarily designed to be in a horizontal position, the SG112-24-NA can be wall-mounted as well.
This device some with 24 Ethernet Gigabit RJ-45 ports (10/100/1000). There are also two combo mini-GBIC (SFP) slots that will convert electric currents to optical signal for fiber optic and high-speed connections.
Again this device uses passive cooling so a cooling fan might be needed. For novices that might seem like a small point, but overheating can shut down your switch and even damage it permanently.
The Cisco Systems SG112-24-NA has a total of 48-gigabytes capacity. Again there is the QoS service function that ensures that streaming data , like VoIP and video, are given priority. There is also Loop Detection, which prevents the system getting caught in broadcast storm created by accidental loops during a continuous broadcast. There are also cable diagnostics that look for cable faults and more.
This device has many of Cisco’s automated controls that make it an excellent choice for small businesses that need more ports, but still want the ease of a plug-n-play ethernet switch.
https://www.buffalotech.com/products/gigabit-green-ethernet-switches
The Buffalo BS-GU 2024 is another unmanaged device, but this one is designed to be rack mounted. That means that it can go into server racks with other devices. It can also be used vertically or horizontally as well as wall-mounted. One interesting set apart is this ethernet switch can be mounted magnetically using an optional mounting package. You could mount it to a filing cabinet or on the outside of a server cabinet.
There are 24 ports on the Buffalo with a total of 48 Gigabits capacity.
One of the Buffalo’s major features is its ability to handle jumbo frames - 9K – Header 14 Bytes + FCS 4 Bytes inclusive. It has a buffer of 512 kb.
The Buffalo is also has 802.3az Green Ethernet technology. It scans for devices that are not operating and turns off power to those ports, saving energy. The ports will remain in sleep mode until the ethernet switch sees an attached device. There is also a loop prevention feature that shuts down any port where a network lop has been detected.
As with most of these devices, the switch communicates with LEDs whose flash patterns tells you if the port is working well or if there is a problem.
The H3C S1850-10P is the first managed ethernet switch on our list. It has 10 Gigabit ports that are easy to administer, allowing you to set the priority of traffic across the switch.
One of the outstanding features of the H3C is that it uses the latest silicon technology making it a more power efficient device, as most ethernet switches are power hogs. Reducing the power usage is an ongoing struggle for switch designers and H3C has made some significant strides.
The S1850-10P is, in fact, a four model series that has three non-PoE version and one PoE+ model. You get all of the other features, but can choose not to have PoE if you don’t need it. The four models provide increasing switching capacity, starting at 20 Gbps and rising to 104 Gbps. The S1850-52P provides massive switching power for even the busiest, high volume system.
With Gigabit SFP ports, the S1850-10P provides fiber connectivity. It can be rack mounted or used on a desktop.
Again, using passive cooling, it's recommended that you use one or two cooling fans with the S1850-10P.
This ethernet router comes with a number of additional features: basic Layer 2 features like VLANs and link aggregation, as well as advanced features such as Layer 3 static routing, IPv6, ACLs, and Spanning Tree Protocols.
The H3C S1850-10P is one of the most economical and effective managed switches you can find and with its varying capacities available, this is a series that will adapt to your needs.
While this is a short list of all of the hundreds of switches available, these devices should meet the needs of any small to medium-sized business needing powerful ethernet switching capabilities.
]]>Routers versus switches can be confusing for some folks. Simply put: switches create networks; routers connect networks. In a more in-depth explanation: switches create local area networks (LANs) while routers connect LANs to wide area networks (WANs).
So, in choosing a router for your business, the major considerations are capacity and security. Here are five excellent choices, with one brand offering a complete series that grows in capacity as you move through the models.
The TP-Link SafeStream TL-ER6020 is an ethernet router the provides great data processing capacity with a built-in VPN. It offers load balance, IM/P2P blocking, Dos defense and more.
This is router designed with security in mind for small businesses, like hotels, restaurants, and other businesses where the clients need super-fast access to large data transference capabilities with high levels of security.
It covers nearly every network and transport protocol: TCP/IP, PPTP, UDP/IP, L2TP, NTP, ICMP/IP, IPSec, PPPoE, SMTP, FTP, DHC. This allows it to adapt easily to an environment.
It’s both desktop and rack mountable. As part of the TP-Link family, it has name recognition and reliability.
https://www.ubnt.com/edgemax/edgerouter-x/
The Ubiquiti Networks EdgeRouter X has carrier-class reliability and offers a great value for the price. An external power source or 24V passive PoE input can power it.
It has a dual-core 880 MHz processor for lightning fast data transference. It can desk or wall-mounted.
The EdgeRouter X has five independent, Gigabit RJ45 ports that are configurable for switching.
The SFP is supported and managed by the Ubiquiti Networks Management System (UNMS). This is a controller that has an intuitive interface and manages registered EdgeMAX devices across multiple sites.
This is a great router at a great price. It should be noted that it is at its most powerful when it’s used with other Ubiquiti devices, although it will work with almost any device.
3. Full router line from H3C - H3C MSR2600/3600/5600 series
https://network-exp.com/collections/router
A focus on the H3C line of ethernet routers can be enlightening. This firm makes affordable routers that have all the same capabilities as the larger name brands, but the power increase can be phenomenal.
A chart of the IPv4 and IPv6 forwarding performance lays out the difference between the devices.
|
MSR26-30 |
MSR36-10 |
MSR36-20 |
MSR36-40 |
MSR36-60 |
MSR56-60 |
MSR56-80 |
IPv4 Forwarding performance |
1.5Mpps |
5Mpps |
5Mpps |
6Mpps |
9Mpps |
12Mpps~ 40Mpps |
12Mpps~ 40Mpps |
IPv6 Forwarding performance |
1Mpps |
4Mpps |
4Mpps |
5Mpps |
7.5Mpps |
10Mpps~30Mpps |
10Mpps~30Mpps |
The key to the H3C line is that in one firm and one-line, small business owners can choose as much capacity as they need, from 1.5 Mpps to 40 Mpps.
The forwarding performance in service ranges from 800 Mbps to 12 Gbps.
This line of routers was designed to accommodate the move to cloud computing. As much of the modern company’s data is off-site and requires fast, safe internet access, the demand on routers has grown exponentially. The H3C line recognizes this by providing a wide range of capabilities.
The entire line offers all major layer 2 protocols: Ethernet, Ethernet II, VLAN (VLAN-BASED PORT VLAN, VOICE VLAN, Guest VLAN), 802.3x, 802.1p, 802.1Q, 802.1x, STP (802.1D), RSTP (802.1w), MSTP (802.1s), PPP, PPPoE Client, PPPoE Server, HDLC, DDR, Modem and ISDN. it also offers static routing and dynamic routing to increase speeds.
The 2600 line is ideal for smaller businesses and even home use. They have the power needed for a home office without the expense or power consumption of larger models.
As with all H3C products, these devices are designed for maximum power efficiency to reduce energy consumption and be as green as possible.
For larger businesses, like hotels, financial institutions, and government agencies, the 5600 line has enough power for almost every application. It’s also ideal for educational institutions that need to provide high-speed access to hundreds of students at once.
Choosing the right router
Finding the right router is a matter of looking at your current needs but predict your future needs. As more of your business is in the cloud or more of your clients, students, and staff need to access WANs to work (or play) you will need more power. Planning now can save a change and any additional expense later.
Bonus: How an ethernet switch and router work together
As was noted above, there is a simple explanation of the difference between a switch and a router:
A switch creates a network - a router connects networks.
Let’s start a home. Most homes these days have a Wi-Fi router. It’s connected to a modem. The modem is the device that brings data on and off of the internet from the internet service provider. The router, usually with a bunch of little antennae sticking out, broadcasts a signal that allows your devices to use the internet. Often, your home router has several ethernet ports that allow you to connect devices directly. This means that the router can also act as a switch.
On a larger business network, these devices are all separate. The modem will still translate data onto and off the internet. The router will connect the internet or other networks to your network. Your network is created by the switch that is in the middle.
When you sit at your workstation, the request you need to see data from the accounting department passes through the switch for your network to a router. The router then sends it to the accounting department network which connects you to the specific device you need.
If you go out to the internet to check the latest football score, your data is sent from your computer to the switch, the switch to the router, the router to the modem, the modem to the internet, and from there to an infinitely complex series of networks, routers, servers, and more to let you know your team won handily and that Larry in the next cubicle owes you a pastry for the bet you just won.
]]>