Layer 2 vs Layer 3: Comprehensive Review of Network Switches
While switch is considered as a core element of any network, yet not all switches compartively. Two the most common types are: Layer 2 switch and Layer 3 switch. All of them have different functions. The perfect one depends on the size and complexity of your network, as well as individual targets. Now, lets get into the differences to these types of switches and how/where to purchase one for your setup.
What is Layer 2 Switch?
A layer 2 switch works at the data link layer of OSI model. The only function for which it is designed to pass traffic based on MAC addresses. Such switches are well suited for building local area networks or LAN that require devices to communicate within a similar network segment.
Main features:
- Works at MAC address level.
- Allows VLAN support, and splits traffic up into by Vlan.
- Works well in small-scale networks, easy and inexpensive.
- Does not route traffic between VLANs or across subnets (requires a router)
Layer 2 switch examples:
- Cisco Catalyst WS-C2960X-48FPS-L
- 48 Fast Ethernet ports with PoE+ support.
- Designed for access-layer deployments in small businesses.
Figure 1: Cisco Catalyst WS-C2960X-48FPS-L
- Ruckus ICX7150-24P
- 24 Gigabit Ethernet ports with PoE+.
- Ideal for small office or branch networks.
Figure 2: RUCKUS ICX 7150-24P Switch
What is Layer 3 Switch?
Layer 3 switch operates on the data link layer and network layer of OSI model. They route traffic based on IP addresses as well as forward packets using MAC addresses. This is why they are used as inter-VLAN routers and in larger, more complex networks.
Main Features:
- Supports routing protocols like OSPF, RIP, and BGP.
- Can route traffic between VLANs or subnets.
- Suitable for core and distribution layers in larger networks.
- Generally more expensive than Layer 2 switches.
Layer 2 switch examples:
- Cisco Catalyst WS-C3850-24XU-S
- 24 Gigabit Ethernet ports with advanced routing capabilities.
- Perfect for enterprise-grade deployments requiring scalability.
Figure 3: Cisco Catalyst WS-C3850-24XU-S
- Ruckus ICX7450-48P
- 48 Gigabit Ethernet ports with PoE+ and modular uplinks for 10G or 40G.
- Ideal for medium to large businesses with complex routing needs.
Figure 4: Ruckus ICX7450-48P
- Juniper EX4300-48T
- 48-port Gigabit Ethernet with Layer 3 routing and Virtual Chassis technology.
- Great for data center top-of-rack or campus deployments.
Figure 5: Juniper EX4300-48T
Layer 2 vs. Layer 3: The Main Differences
|
Feature |
Layer 2 Switch |
Layer 3 Switch |
|
Operation Level |
Data Link Layer |
Network Layer |
|
Addressing |
MAC Address |
IP Address |
|
Inter-VLAN Routing |
Requires External Router |
Built-in Routing Capabilities |
|
Use Case |
Small LANs |
Large Networks/Complex Topologies |
|
Examples |
WS-C2960X-24TS-L |
WS-C3850-24XU-S |
When to Use a Layer 3 Switch
If your network needs:
- Routing between VLANs or subnets.
- Enhanced routing protocol support.
- It scales for big or mid-sized businesses.
Recommended Models:
- Cisco Nexus N3K-C3064PQ-10GX: Ideal for high throughput data center applications
- Dell Networking N3048ET-ON: Enterprise-grade 48-port Layer 3 switch.
Layer 2+ Switches: A Hybrid Option
Some switches like the Cisco Catalyst 2960X-24PS-L are classified as for example Layer 2+. These are mostly Layer 2 devices with some routing functions (for example, static routing) and can be referred to as Layer 3. This is an inexpensive and suitable solution for businesses that need minimal routing but do not require the full capabilities of a layer 3 switch.
In conclusion, the decision to use Layer 2 or Layer 3 switches is really a function of how large and complex your network is. A WS-C2960X-48FPD-L is all you need for a Layer 2 switch for simple small network. But if your network is larger and requires VLAN routing than a Layer 3 switch such as an ICX7450-48P or WS-C3850-24XS-S is the solution.
Knowing what your network has to do and where it is going will help you encompass a simple, reliable decision that offers the right combination of performance, scalability and cost.
