Contents
- 1 What is the maximum number of MAC addresses that are allowed on a switch port?
- 2 Which command uses MAC address in Switchport security on switch?
- 3 Why is switch port security overlooked?
- 4 What does Switchport port security MAC address sticky do?
- 5 What is the default port security setting on a switch port?
- 6 What is the benefit of configuring MAC address sticky?
- 7 When do MAC addresses on a port become insecure?
- 8 What happens when you assign a secure MAC address?
What is the maximum number of MAC addresses that are allowed on a switch port?
one
The switch must only allow a maximum of one registered MAC address per access port.
Which command uses MAC address in Switchport security on switch?
switchport port security example
| Command | Description |
|---|---|
| Switch(config-if)#switchport port-security | Enable port security feature on this port |
| Switch(config-if)#switchport port-security maximum 1 | Set limit for hosts that can be associated with interface. Default value is 1. Skip this command to use default value. |
What happens when you exceed the maximum number of different Macs on a port using port security?
If a port is configured as a secure port and the maximum number of secure MAC addresses is reached, when the MAC address of a station attempting to access the port is different from any of the identified secure MAC addresses, a security violation occurs.
How do I configure a port security on a Cisco switch?
Configuration Steps:
- Your switch interface must be L2 as “port security” is configure on an access interface.
- Then you need to enable port security by using the “switchport port-security” command.
- This step is optional, but you can specify how many MAC addresses the switch can have on one interface at a time.
Why is switch port security overlooked?
One of the most overlooked security areas is the configuration of individual switchport security configuration. The reason may be that it requires a more granular configuration; this is because a typical configuration requires the knowledge of the specific MAC address(es) that will be connecting to each switchport.
What does Switchport port security MAC address sticky do?
Sticky – Sticky secure MAC addresses are a hybrid. They are learned dynamically from the devices connected to the switchport, are put into the address table AND are entered into the running configuration as a static secure MAC address (sometimes referred to as a static sticky MAC address).
What are the steps to configure port security?
To configure port security, three steps are required:
- define the interface as an access interface by using the switchport mode access interface subcommand.
- enable port security by using the switchport port-security interface subcommand.
How do you show port security violations?
Here is a useful command to check your port security configuration. Use show port-security interface to see the port security details per interface. You can see the violation mode is shutdown and that the last violation was caused by MAC address 0090.
What is the default port security setting on a switch port?
The default configuration of a Cisco switch has port security disabled. If you enable switch port security, the default behavior is to allow only 1 MAC address, shutdown the port in case of security violation and sticky address learning is disabled. Next, we will enable dynamic port security on a switch.
What is the benefit of configuring MAC address sticky?
Sticky MAC prevents traffic losses for trusted workstations and servers because the interface does not have to relearn the addresses from ingress traffic after a restart. Solution: Enable Sticky MAC in conjunction with MAC limit to restrict the number of MAC addresses learning.
What is the purpose of port security?
Port Security helps secure the network by preventing unknown devices from forwarding packets. When a link goes down, all dynamically locked addresses are freed. The port security feature offers the following benefits: You can limit the number of MAC addresses on a given port.
Is there a maximum number of MAC addresses for port security?
If the entire global resource of 1024 MAC addresses is used on some ports, you can still enable port security on the rest of the ports with a maximum of one MAC per port. If you reduce the maximum number of MAC addresses, the system clears the specified number of MAC addresses and displays the list of removed addresses.
When do MAC addresses on a port become insecure?
After you allocate a maximum number of MAC addresses on a port, you can also specify how long the addresses on the port will remain secure. After the age time expires, the MAC addresses on the port become insecure. By default, all addresses on a port are secured permanently.
What happens when you assign a secure MAC address?
When you assign secure MAC addresses to a secure port, the port does not forward packets with source addresses outside the group of defined addresses. If you limit the number of secure MAC addresses to one and assign a single secure MAC address, the workstation attached to that port is assured the full bandwidth of the port.
How to configure port security on Cisco routers?
• 901 (1 + 900) on one port, 101 (1 + 100) on another port, 25 (1 + 24) on a third port, and 1 address on each of the rest of the ports After you allocate the maximum number of MAC addresses on a port, you can either specify the secure MAC address for the port manually or have the port dynamically configure the MAC address of the connected devices.