In security monitoring, smart home, enterprise office and other scenarios, PoE switches become the core networking equipment because they can simultaneously realize data transmission and power supply. However, with the increase of access devices, security risks such as single port being attacked and broadcast storm spreading become prominent. Port isolation has become a key operation to ensure network security. As a PoE switch manufacturer who has been deeply involved in the industry for 10 years, this article will explain the setting method and security value of port isolation in detail based on the practical operation experience of self-developed equipment to help you quickly build a network protective wall.
1、 Why must PoE switches be port isolated? Early avoidance of safety risks
Most users only pay attention to the power supply stability of PoE switches, but ignore the risk of data interaction between ports. When port isolation is not enabled, there may be three security problems:
Broadcast storm spread: when a port is connected to a faulty device (such as a loop switch), the generated broadcast packet will spread across the entire network through all ports, resulting in camera jam and AP disconnection, affecting the overall networking;
Cross port attack penetration: if an IPC (webcam) is hacked, the attacker can access other devices (such as storage servers and office computers) through the non isolated ports to steal monitoring data or tamper with configuration;
Equipment conflict interference: If access equipment in different areas (such as foreground AP and workshop IPC) share the same broadcast domain, the equipment may be offline due to IP conflict and protocol incompatibility, which increases the difficulty of operation and maintenance.
When designing professional PoE switch manufacturers, they will take "port isolation" as the core security function, support flexible isolation strategies, not only do not affect the stability of PoE power supply, but also achieve data isolation - which is also one of the key indicators to distinguish ordinary switches from industrial PoE switches.
2、 Two core setting methods of PoE switch port isolation, and demonstration of manufacturer's equipment
The setting logic of PoE switches of different brands is similar, but the self-developed equipment will optimize the operation interface and compatibility. The following takes the 8-port gigabit PoE switch (model: GS0402FP) of the PoE switch manufacturer as an example to explain the two mainstream configurations:
（1） Web graphical interface configuration: novice friendly, completed in three steps
Web interface is the first choice of most users. The PoE switch manufacturer simplifies the operation process and can quickly set without professional technology:
Login management interface
Connect the "management port" of the PoE switch to the computer with a network cable, enter the manufacturer's default management IP in the browser (such as 192.168.1.1, which can be viewed in the device label or manual), and enter the user name and password (which can be modified when logging in for the first time);
Enter the port isolation configuration page
Find [Port Management] → [Port Isolation] in the left menu bar, and select the port to be configured (such as 1-6 ports connected to the camera, 7 ports connected to the server);
Set isolation groups and rules
Create a new "isolation group 1", add 1-6 ports to the group, and check "port isolation in the group" (no mutual access between ports in the group);
Set 7 ports as "non isolated ports" separately, and check "Allow communication with isolation group" (ensure that the server can receive camera data from ports 1-6, and the isolation group cannot access 7 ports);
Click [Save Configuration], and the PoE exchange will take effect automatically without restarting (the manufacturer's equipment supports the "configuration takes effect in real time" function to avoid the impact of network disconnection).
（2） CLI command line configuration: suitable for batch management and more efficient
For scenarios where multiple PoE switches need to be configured in batch (such as security projects in large parks), the PoE switch manufacturer supports the CLI command line. After logging in through the serial port or Telnet, enter the following commands (taking isolated ports 1-3 as an example):
#Enter global configuration mode
Switch>enable
Switch # configure terminal
#Create isolation group 1 and add ports 1-3
Switch (config) # port isolate group 1
Switch (config-group-1) # switchport interface gigabitEthernet 0/1-3
#Set intra group isolation rules (intra group ports are prohibited from mutual access)
Switch (config-group-1) # isolate intra group enable
#Save Configuration
Switch (config-group-1) # exit
Switch # write memory
Tip: The command syntax of different PoE switch manufacturers may be slightly different. When purchasing, you can ask the manufacturer for the Command Line Configuration Manual, or contact the technical team to obtain a customized configuration scheme.
3、 Port isolation techniques in different scenarios: practical suggestions from PoE switch manufacturers
Port isolation is not "one size fits all" and needs to be flexibly configured in combination with the scenario. The following is the optimization scheme of the PoE switch manufacturer for the three mainstream scenarios:
1. Security monitoring scene: "one-way isolation" between camera and server
Requirements: 16 way IPC needs to transmit data to NVR (network hard disk recorder), but IPC cannot exchange access to prevent the single way camera from affecting other devices after being attacked;
Configuration: Add 1-16 ports to isolation group 1 (isolation within the group), set the 17 ports connected to NVR as "allow communication with isolation group", and enable the "port speed limit" function of the manufacturer's equipment (speed limit of each port is 20Mbps) to prevent the bandwidth of a single camera from being occupied too much.
2. Enterprise office scenario: "horizontal isolation" between departments
Demand: The Marketing Department (1-5 ports) and the Technology Department (6-10 ports) need to access the gateway (11 ports), but the departments cannot exchange visits to protect the security of technical documents;
Configuration: create isolation group 2 (1-5 ports) and isolation group 3 (6-10 ports), set "inter group isolation+intra group isolation", only allow two groups of ports to access 11 ports, and further narrow the broadcast domain through the manufacturer's "VLAN and port isolation linkage" function.
3. Smart home scenario: terminal equipment "fully isolated"
Requirements: The living room AP (1 port), bedroom camera (2 ports) and kitchen sensor (3 ports) need to be connected to the router (4 ports), but no mutual access between terminals to prevent camera data from being stolen by sensor equipment;
Configuration: Add 1-3 ports to independent isolation groups (only one port in the group), all groups are allowed to access 4 ports, and use the "lightweight network management" function of the manufacturer's PoE switch to view the port status in real time through the mobile phone APP to simplify the operation and maintenance of home users.
4、 PoE switch manufacturer reminds: three configuration errors should be avoided
Many users fail to isolate or supply power abnormally due to improper operation during setting. In combination with the case of 100000+users, the PoE switch manufacturer summarizes the common mistakes:
Myth 1: Power off PoE after isolating port
Port isolation only isolates "data frame transmission" and does not affect PoE power supply (IEEE 802.3af/at standard). In case of power supply interruption, check whether "port shutdown" is ticked by mistake instead of isolation function;
Myth 2: All ports join the same isolation group
The gateway, server and other core equipment do not need to be isolated. If the isolation group is added, the entire network will be disconnected. The correct approach is to set the core equipment as a "non isolated port" and only isolate the access layer equipment;
Myth 3: Ignore configuration saving
The configuration of some switches will be lost after restart, so it is necessary to use the "Auto Save" function of the manufacturer's equipment (enabled in [System Management] → [Configuration Management]), or manually execute the "write memory" command to avoid configuration reset after power failure.
5、 Select the right PoE switch manufacturer for more convenient security configuration
The effect of port isolation depends not only on the setting method, but also on the hardware performance and software compatibility of the device. High quality PoE switch manufacturers should have three advantages:
Functional compatibility: support 802.3af/at/bt full standard PoE power supply, and the isolation function does not conflict with power supply, VLAN, QoS and other functions;
Operation and maintenance convenience: provide multi terminal management of Web, CLI and APP, support configuration backup/recovery, and novices can quickly get started;
After sales guarantee: if the PoE switch manufacturer provides 7 × 24 hours of technical support, it can remotely assist in troubleshooting isolation configuration problems, and the equipment has a five-year warranty to reduce the later maintenance costs.
If you encounter problems in the port isolation setting, or need to customize the PoE networking scheme according to the scenario, you can contact the technical team of the PoE switch manufacturer to obtain the Port Isolation Configuration Guide and the device test prototype for free to make the security networking easier.