Modular switches, as the name implies, allows you to add expansion modules into the switches as needed, thereby delivering the best flexibility to address changing networks. Examples of expansion modules are application-specific (such as Firewall, Wireless, or Network Analysis), modules for additional interfaces, power supplies, or cooling fans. Cisco Catalyst 4K and 6K are good examples of Modular switches.
Fixed Configuration switches are switches with a fixed number of ports and are typically not expandable. This category is discussed in further detail below. Cisco Catalyst 2K, 3K and the Cisco 300/500 series are good examples of Fixed Configuration switches.
This category of a switch is the most cost-effective for deployment scenarios that require only basic layer 2 switching and connectivity. As such, they fit best when you need a few extra ports on your desk, in a lab, in a conference room, or even at home.
With some Unmanaged switches in the market, you can even get capabilities such as cable diagnostics, prioritization of traffic using default QoS settings, Energy savings capabilities using EEE (Energy Efficient Ethernet) and even PoE (Power Over Ethernet). However, as the name implies, these switches generally cannot be modified/managed. You simply plug them in and they require no configuration at all.
This category of switches is the most blurred and fastest changing. The general rule here is that these switches offer certain levels of Management, QoS, Security, etc. but is “lighter” in capabilities and less scalable than the Managed switches. It, therefore, makes them a cost-effective alternative to Managed switches. As such, Smart switches fit best at the edge of a large network (with Managed Switches being used in the core), as the infrastructure for smaller deployments, or for low complexity networks in general.
The capabilities available for this Smart switch category vary widely. All of these devices have an interface for Management – historically a browser-based interface used to be the only way to configure these devices, though nowadays you can manage some of these devices with CLI and/or SNMP/RMON as well. Regardless, these capabilities are lighter than what you will find in their Managed switch counterparts. Smart switches tend to have a management interface that is more simplified than what Managed Switches offer.
They also offer some levels of security, such as 802.1x endpoint authentication, and in some cases with limited numbers of ACLs (access control lists), though the levels of control and granularity would not be the same as a Managed switch.
Managed Switches are designed to deliver the most comprehensive set of features to provide the best application experience, the highest levels of security, the most precise control and management of the network, and offer the greatest scalability in the Fixed Configuration category of Switches. As a result, they are usually deployed as aggregation/access switches in very large networks or as core switches in relatively smaller networks. Managed switches should support both L2 switching and L3 IP routing though you’ll find some with only L2 switching support.
From a Security perspective, Managed switches provide protection of the data plane (User traffic being forwarded), the control plane (traffic being communicated between networking devices to ensure user traffic goes to the right destination), and management plane (traffic used to manage the network or device itself). Managed switches also offer network storm control, denial-of-service protection, and much more.
The Access Control List capabilities allow for flexibly dropping, rate limiting, mirroring, or logging of traffic by L2 address, L3 address, TCP/UDP port numbers, Ethernet type, ICMP or TCP flags, etc.
Managed switches are rich in features that enable them to protect themselves and the network from deliberate or unintended Denial of Service attacks. It includes Dynamic ARP Inspection, IPv4 DHCP snooping, IPv6 First Hop Security with RA Guard, ND Inspection, Neighbor Binding Integrity, and much more.
Additional Security capabilities may include Private VLANs for securing communities of users or device isolation, Secure Management (downloads through SCP, Web-based Authentication, Radius/TACACS AAA, etc), Control Plane Policing (CoPP) for protecting the CPU of the switch, richer support for 802.1x (time-based, Dynamic VLAN Assignment, port/host-based, etc)
From a Scalability perspective, these devices have large table sizes so that you can create large numbers of VLANs (for workgroups), devices (MAC table size), IP routes, and ACL policies for flow-based security/QoS purposes, etc.
For highest network availability and uptime, Managed switches support L3 redundancy using VRRP (Virtual Router Redundancy Protocol), large numbers of Link Aggregation groups (which is used both for scalability and resiliency), and capabilities for protecting L2 such as Spanning Tree Root Guard and BPDU Guard.
When we talk about QoS and Multicast features, the richness of capabilities goes far beyond what you’d see in a Smart Switch. Here you’d see things such as IGMP and MLD Snooping with Querier functions for optimizing IPv4/v6 multicast traffic in the LAN, TCP Congestion Avoidance, 4 or 8 queues to treat traffic differently by importance, setting/tagging traffic by L2 (802.1p) or L3 (DSCP/TOS), and rate limiting traffic.
In terms of Management, things such as multiple ways to configure (using CLI, Web GUI, SNMP Management application), discovering of neighbor devices in the networks (using CDP, LLDP, Bonjour, etc), and troubleshooting capabilities (such as VLAN and Port Mirroring, Traceroute, Ping, Syslog, Cable Diagnostics, RMON, etc) are all included.
Managed Switches can go even further than what I’ve highlighted. For example, there’s even richer support for Dynamic Unicast and Multicast Routing protocols, deeper flow intelligence or macro flow statistics with Netflow/SFlow, non-Stop Forwarding capabilities, MPLS/VRF support, Policy enforcement, and many others.
You can find Fixed Configuration switches in Fast Ethernet (10/100 Mbps), Gigabit Ethernet (10/100/1000 Mbps), Ten Gigabit (10/100/1000/10000 Mbps) and even some 40/100 Gbps speeds. These switches have a number of uplink ports and a number of downlink ports. Downlinks connect to end users – uplinks connect to other Switches or to the network infrastructure. Currently, Gigabit is the most popular interface speed though Fast Ethernet is still widely used, especially in price-sensitive environments. Ten Gigabit has been growing rapidly, especially in the datacenter and, as the cost comes down, it will continue to expand into more network applications. With 10GBase-T Ten Gigabit copper interfaces being integrated into LOM (LAN on the Motherboard) and 10G-Base-T switches becoming available now (see the new Cisco SG500XG-8F8T 16-port 10-Gigabit switch), building a Storage or Server farm with 10 Gigabit interfaces has never been easier or more cost-effective. 40G/100G is still emerging and will be mainstream in a few years.
Fixed Configuration Switches typically come in 5, 8, 10, 16, 24, 28, 48, and 52-port configurations. These ports may be a combination of SFP/SFP+ slots for fiber connectivity, but more commonly they are copper ports with RJ-45 connectors on the front, allowing for distances up to 100 meters. With Fiber SFP modules, you can go distances up to 40 kilometers
Power over Ethernet is a capability that facilitates powering a device (such as an IP phone, IP Surveillance Camera, or Wireless Access Point) over the same cable as the data traffic. One of the advantages of PoE is the flexibility it provides in allowing you to easily place endpoints anywhere in the business, even places where it might be difficult to run a power outlet. One example is that you can place a Wireless Access Point inside a wall or ceiling.
Switches deliver power according to a few standards – IEEE 802.3af delivers power up to 15.4 Watts on a switch port whereas IEEE 802.3at (also known as POE+) delivers power up to 30 Watts on a switch port. For most endpoints, 802.3af is sufficient but there are devices, such as Video phones or Access Points with multiple radios, which have higher power needs. It’s important to point out that there are other PoE standards currently being developed that will deliver even high levels of power for future applications. Switches have a power budget set aside for running the switch itself, and also an amount of power dedicated to POE endpoints.
To find the switch that is right for you, all you need to do is choose a switch according to your power needs. When connecting to desktops or other types of devices which do not require POE, the non-POE switches are a more cost-effective option.View Less