The switchport security feature port security is an important piece of the network switch security puzzle. With this new lower aging time i have to wait only one minute to move the device, but my questions are. Port security allows you to restrict a ports ingress traffic by limiting the mac addresses that are allowed to send traffic into the port. Setting port security to a max of 2, will allow the switch to learn two mac addresses. Port security supports access and trunking etherchannel port channel interfaces. To configure port security we need to access the command prompt of switch. A best approach to securing a switchis to apply port security. Switchport security is not supported on switch port analyzer span destination ports. Often though, a single switch interface can support multiple speeds. When a mac address, or a group of mac addresses are configured to enable switch port security, the switch will forward packets only to the devices using those mac addresses. Port security is essentially a layer 2 security mechanism that can limit the number of mac addresses that can be learned on a single switch port or perhaps be used as a security barrier to prevent anyone from unplugging a network device and plugging in a new device without authorization.
Port security uses the vlan id configured with the switchport trunk native vlan command. Packets that have a matching mac address secure packets are. Doesnt forward traffic of unspecified devices addresses will be lost when the switchport goes down or switch reboots. You can see the violation mode is shutdown and that the last violation was caused by mac address 0e. Port 02 should go to shutdown state if other mac address device try to connect. Conventional network security often focuses more on routers and blocking traffic from the outside. To allow the switchport fastethernet 04 to accept only one device enter port security as follows. Sep 27, 2015 port security with dynamic mac addresses dynamically configure secure mac addresses of devices connected to port. Verify port security background in this activity, you will configure and verify port security on a switch. By default, the maximum number of allowed mac addresses are one, so if we connect another host to the same port, the security violation will occur. Backgroundpreparation cable a network similar to the one in the diagram.
May 03, 2010 port security is a layer two traffic control feature on cisco catalyst switches. Port security is a way to limit which systems can connect to a switch. This enables individual ports to detect, prevent, and log attempts by unauthorized devices to communicate through the switch. After reminding him of the security policy that does not allow personal devices on the network, you now must reconnect pc1 and reenable the port. Switches are internal to the organization, and read more. Cisco switch port security configuration and best practices. Port security supports access and trunking etherchannel portchannel interfaces. One approach is to manually configure the mac address. When a link goes down, all dynamically locked addresses are freed. Take care when you enable port security on the ports connected to. Once the switch sees another mac address on the interface it will be in violation and something will happen. I have reduced the port security type inactivity aging time to the minimum 1 minute because when you move a data device laptop from an ip phone to another port of the same switch port security blocks this device.
Configure port security on individual fastethernet ports. To enable portsecurity youll execute the switchport portsecurity command as. Verify port security is enabled and the mac addresses of pc1 and pc2 were added to the running configuration with show run command. Packet tracer troubleshooting switch port security. Understanding switch port security linkedin learning. Oct 11, 2007 one way to boost network security is to use ciscos port security feature to lock down switch ports. Port security can be used to limit access on an ethernet port based on the mac address of the device to which it is connected. The status code of errdisabled means that the security violation occured on. A best approach to securing a switch is to apply port security. How to configure switchport security example switchport security makes it possible to limit the number and type of devices that are allowed on the individual switchports.
Cisco ccna port security and configuration switch port security limits the number of valid mac addresses allowed on a port. Port security is essentially a layer 2 security mechanism that can limit the number of mac addresses that can be learned on a single switch port or perhaps be used as a security barrier to prevent anyone from unplugging a network device and plugging in. Requirements disconnect home laptop and reconnect pc1 to the appropriate port. Attach rogue laptop to any unused switch port and notice that the link lights are red. Port security helps secure the network by preventing unknown devices from forwarding packets. For example, a gigabit ethernet interface is often backwardscompatible with original and fast ethernet, and is referred to as a 10100 interface. Port security can be used to block input to an ethernet, fast ethernet, or gigabit ethernet switch port. While the name of this feature is a bit vague, it makes it possible to limit the number and type of devices that are allowed on the. When pc1 was reconnected to the switch port, did the port status change. Learn the basics of port security, and find out how to configure this feature.
However with sticky only those devices were allowed which were learnt i. Switch and vlan security switch port security port security adds an additional layer of security to the switching network. Configuring sticky switchport security free ccna workbook. Switches can be subject to mac address table overflow attacks, mac spoofing attacks, and unauthorized connections to switch ports. If a packet with a valid mac address is received on a particular port then the switch will allow that packet to pass through the switching fabric of the switch as normal. The mac address learned on the port can also be added to the running configuration of that port. Port security allows you to restrict a ports ingress traffic by limiting the mac addresses that are allowed to send traffic. While the name of this feature is a bit vague, it makes it possible to limit the number and type of devices that are allowed on the individual switchports. The employee who normally uses pc1 brought his laptop from home, disconnected pc1 and connected the laptop to the telecommunication outlet. Using port security, you can configure each switch port with a unique list of the mac addresses of devices that are authorized to access the network through that port. This is a way to limit which device can connectto a switch on a given port.
I have configured portsecurity so only one mac address is allowed. Use show port security interface to see the port security details per interface. By default, port security will allow only one mac on an interface. When configuring switchport security on a switchport that is configured with a voice vlan, ensure that the maximum number of mac addresses is raised to account for the voice and. This enables individual ports to detect, prevent, and log attempts by unauthorized devices to communicate through the. The total supply, or global resource, of mac addresses for the switch is 1024 mac addresses. Port security does not support etherchannel portchannel interfaces. Layer 2 managed switches can typically implement port security which consists of checking incoming packets for a matching mac address. Pdf packet tracer configuring switch port security. The mac address of a host generally does not change. Set maximum number of allowed mac addresses to port fastethernet 02 to 1. From privilege exec mode use configure terminal command to enter in global configuration mode. Configuring and monitoring port security ftp directory listing.
Attach rogue laptop to any unused switch port and notice that the link lights are. Try to test your switch port security configuration with ping command and testing with the rogue laptop on the lab. This enables to keep out an unauthorised entry into the network. How to configure switch port security on cisco switches. Enable portsecurity on sw1s fa01 interface and configure the interface to sticky the mac address learned. Switch port configuration speed and duplex some switch interfaces are fixed at a single speed. Packet tracer configuring switch port security topology addressing table device interface ip address subnet mask s1 vlan 1 10. Next, by using the show port security interface fa01 we can see that the switch has learned the mac address of host a.
Port security is a layer two traffic control feature on cisco catalyst switches. Doesnt forward traffic of unspecified devices addresses will be. Port security with dynamic mac addresses dynamically configure secure mac addresses of devices connected to port. To configure the port to learn only 1 mac address, we need to set maximum to 1. The port security feature offers the following benefits. To enable portsecurity youll execute the switchport portsecurity command as previously learned in lab 419. Another approach is to automatically,or allow the switch, to automatically learnthe mac address. Packet tracer troubleshooting switch port security scenario. Mar 29, 2020 this article describes how to configure switch port security on cisco switches. When connected, new ms125 switches automatically reach out to the meraki cloud and download the most current configuration. Future updates can be userscheduled, ensuring the network is kept uptodate with bug fixes, security updates, and new features.
Port security does not support etherchannel port channel interfaces. For example, port security on cisco switches can be used to stop macflooding attacks or prevent nonauthorized hosts to connect to the switch. Switchport security concepts and configuration cisco press. Follow the below commands to configure port security on a cisco switch. Port security does not support switch port analyzer span destination ports. One way to boost network security is to use ciscos port security feature to lock down switch ports. To practice and learn to configure port security on cisco switch, just download the port security packet tracer lab or create your own lab and follow the switch port security configuration guideline. I have reduced the portsecurity type inactivity aging time to the minimum 1 minute because when you move a data device laptop from an ip phone to another port of the same switch portsecurity blocks this device. From global configuration mode enter in specific interface. Mar 15, 2018 in this activity, you will configure and verify port security on a switch. This tutorial explains switchport security modes protect, restrict and shutdown, sticky address, mac address, maximum number of hosts and. Switchport security is not supported along with etherchannel fast or gigabit. It enables an administrator configure individual switch ports to allow only a specified number of source mac addresses ingressing the port.
In macflooding, an attacker can connect a laptop into an empty switch port or empty rj45 wall socket, and he can use hacking tools to generate millions of ethernet frames with fake source mac. Dear all, with dynamic port security, i was able to disconnect one device and able to connect other one. When configuring the security for a network, it is important to take advantage of the security features of all deployed devices. Port security capabilities are dependant on the platform allows you to specify mac addresses for each port, or to learn a certain number of mac addresses per port upon detection of an invalid mac the switch can be configured to block only the offending mac or just shut down the port port security prevents macof from flooding the cam table. Mar 20, 2020 switches can be subject to mac address table overflow attacks, mac spoofing attacks, and unauthorized connections to switch ports. Once an organization decides to utilize the switchport. This is a way to limit which device can connect to a switch on a given port. Click switch and click cli and press enter key port can be secure from interface mode. Learn how to secure a switch port with switchport security feature step by step. Here is a useful command to check your port security configuration.
Pdf packet tracer configuring switch port security objective part. It provides guidelines, procedures, and configuration examples. The port has the maximum number of mac addresses that is supported by a layer 2 switch port which is configured for port security. Configuring dynamic switchport security free ccna workbook. One approach is to manually configure the mac addressfor the directly connected device. Configuring and monitoring port security overview overview using port security, you can configure each switch port with a unique list of the mac addresses of devices that are authorized to access the network through that port. You will configure port security to limit the number of mac addresses that can be learned on a switch port and disable the port if that number is exceeded. After reminding him of the security policy that does not allow personal devices on the network, you now must reconnect pc1 and reenable the. This code example uses a sticky mac address that tells the switch to configure the port for whatever. One of the security features available with cisco switches among other vendors is switchport security. If a specific host will always remain connected to a specific switch port, then the switch can filter all other mac addresses on that port using port security.
You can limit the number of mac addresses on a given port. Next, by using the show portsecurity interface fa01 we can see that the switch has learned the mac address of host a. Cisco switch port security commands the tech factors. Access the command line for s1 and enable port security on fast ethernet ports 01 and 02. What is port security and how does it work with my managed. Port security allows you to restrict a port s ingress traffic by limiting the mac addresses that are allowed to send traffic into the port. An interface in the default mode dynamic desirable cannot be configured as a secure port. On a port configured for port security, the switch keeps a table of secure mac address entries. This tutorial explains switchport security modes protect, restrict and shutdown, sticky address, mac address, maximum number of hosts and switchport security violation rules in detail with examples. If you configure port security on one or more ports that are later added to a trunk group, the switch will reset the port security parameters for those ports to the. The switch port must be an access port else we cannot apply switch port security on that port. It also can be used to limit the total number of devices plugged into a switch port, thereby protecting the switch from a mac flooding attack as well as reducing the risks of rogue wireless access points or hubs.