I want to buy a new switch to replace an old one which is unmanaged and I see that there are smart and managed switches.. what it the difference?
Terms like "smart switch" and "managed switch" are terms invented by vendors. As such the exact meaning may vary from vendor to vendor.
In general "managed" switches are aimed at large proffesionally managed networks where people are prepared to pay substantial money for advanced management features and/or perceived reliability. They will typicaly have a serial console port allowing recovery from misconfigurations with minimal downtime.
At the other extreme "unmanaged" switches offer no management capability at all and are dirt cheap.
"smart" switches fill a middle ground. They have some management facilities and support VLANS but will often be lacking stuff compared to a conventional managed switch, for example:
- They usually lack a serial console port. So if you screw up the configuration too badly or just forget the password your only option is a reset to factory defaults.
- Some of them have no ability to configure the VLAN for the management interface and may do strange things regarding the management port and VLANS (I've seen reports of some where the management IP can be reached from the native VLAN on any port).
- Some of them can only be configured by a web interface.
- Some of them can only be configured with a vendor-provided client application.
- They are unlikely to support features for automatically pushing configuration to multiple switches in a network.
Some vendors further divide their smart switches into multiple teirs, for example TP-link have their "websmart/easysmart" line which seem like total crap and their "smart" line which seems fairly decent.
Before buying any peice of networking gear I would suggest downloading and reading the manual. This will tell you whether it suffers from brain damage like no VLAN setting for the management port and whether it supports the features you need.
What are the differences in features and application scenarios among various serial switches?
There is L2/L3 managed Switch, Smart Switch, Easy Smart Switch and Unmanaged Switch in TP-LINK official website, this article will give a brief account about the features and application scenarios of the respective switch.
You are not able to configure the unmanaged switch because it doesn’t support any configuration interface or options. It is plug-and-play, so you only need to connect your computer or other network devices to the unmanaged switch directly. Therefore, if you do not need any L2 features, but only need to extend the number of Ethernet ports, unmanaged switch is the right switch for you.
Easy Smart Switch
You can use Utility or Web interface (Web only for TL-SG1016DE and TL-SG1024DE) to manage easy smart switch and configure basic settings, such as VLAN, QoS and a few L2 features like LAG, IGMP Snooping and Port Mirroring. If there are no advanced applications needed, easy smart switch should be the best choice for you. Normally, easy smart switch will be found in the home, SOHO or small business.
Smart switch can be managed by Web interface, Telnet, SSH and SNMP. It supports far more L2 features and better QoS than easy smart switch, additionally, smart switch supports more advanced functions like ACL and Spanning Tree protocol, if you want to support a solution for one small company or colleague with a lower price, the Smart switch is the indispensable device.
L2 Managed Switch
L2 managed switch has a console port for CLI (Command Line Interface), it has all the managing ways and advanced features that smart switch has, besides, L2 managed switch has abundant VLAN and Multicast features as well as cluster for logical stacking and Network Security features including 802.1X and IP-MAC binding. So you can use L2 managed switch to build a resiliency and availability network or even build up a small ISP Access Network.
L3 Managed Switch
L2 switch could only work in Layer 2--Data Link Layer of OSI model. But Layer 3 switch has some L3 functions just like a traditional router--static routing, routing protocol like OSPF and ECMP, multicast routing protocol and DHCP relay. Compared with a traditional router, L3 switch has lower cost but better performance in packet routing speed because the layer 3 switch routes packets by its hardware--ASIC instead of CPU, once it learned the IP address, it will forward packets by switching performance. It is mainly used in the core layer of a middle sized business network, providing better hardware switching performance in routing.
Managed switches boast of many features and allow full configuration via CLI (command line instructions) and in most cases offer also a web interface to easily configure the most options. They provide the ability to monitor each device on the network as well as limit the amount of bandwidth any device can use.
Smart switches enjoy some capabilities that managed one have, but are more limited, cost less than managed switches and cost more than unmanaged ones. They can make an excellent transition solution when the cost of a managed switch cannot be justified.
More detailed information:http://www.makeuseof.com/answers/difference-unmanaged-smart-managed-switches/
Those are marketing terms. They have no technical meaning based on industry stamdards (IEEE / IETF / OSI). If you dont know which to purchase or which you need you would benefit from contacting a networking equipment reseller. Each manufacturer's website usually has a way to search for certified resellers in your area.