The Cisco Catalyst switches provide a feature called port security that is a layer two traffic control function. It gives administrators the ability to set individual switch ports such that only a certain number of source MAC addresses are permitted to enter the port at any given time.
What does “port security” mean?
A more comprehensive definition of marine security includes port security as an integral component. It is a term that refers to the actions of defending the nation, enforcing laws and treaties, and fighting terrorism that take place inside the port and marine realm.
How does a switch’s port security function?
Port Security contributes to the overall security of the network by obstructing the ability of unknown devices to forward packets. When a link is disabled, all dynamically locked addresses are unlocked and available for use again. The ability to restrict the amount of MAC addresses that may be used on a particular port is one of the advantages provided by the port security feature.
What three types of port security are there?
There are three primary sorts of security violations that may occur on Cisco hardware: shutdown, protect, and restrict.
What are violations of switch port security?
When a device with a different MAC address attempts to join to a port after the maximum number of secure MAC addresses has been reached, this constitutes a security breach. When the switch determines that there has been a breach of security, it will, in the vast majority of cases in use today, immediately disable that port.
What advantage does port security provide?
Advantages of Port Safety and Security
It is possible to set a cap on the total number of MAC addresses that can be used on a particular port. Only packets that have a matching MAC address, known as secure packets, are let through, while all other packets, known as unsecure packets, are prevented from doing so. Individual ports can have this feature enabled. When the lock is engaged, only packets that contain an acceptable MAC address will be sent.
How crucial is port safety?
Stops Thieves from Stealing Goods from Your Store. The importance of port security in preventing products from being stolen is underscored by the fact that shipping containers cannot be staffed continuously. Although there are portions of ports that are unavailable to human patrol, additional security systems can nevertheless safeguard the goods from being taken.
I need to configure port security.
To configure port security, three steps are required:
- Use the switchport mode access interface subcommand to designate the interface as an access interface.
- Use the switchport port-security interface subcommand to enable port security.
How can I check the security of my Switchport?
In order to view the port security information for each interface, use the show port-security interface command. You can see that the violation mode is shutdown and that MAC address 0090 was the one responsible for the most recent violation.
What is Cisco sticky MAC?
Sticky MAC is a feature of port security that dynamically learns MAC addresses on an interface and stores that knowledge so it may be retrieved even if the Mobility Access Switch is rebooted.
How do I make a Cisco switch’s ports secure?
Configuration Steps:
- Since “port security” is configured on an access interface, your switch interface must be L2.
- The “switchport port-security” command must then be used to enable port security.
- You can specify how many MAC addresses the switch can have on a single interface at once in this optional step.
Describe PortFast.
Cisco’s PortFast is a feature designed for use in PVST+ settings. When a switch port is configured using PortFast, the port goes straight from the blocking state to the forwarding state, skipping over the typical 802.1D STP transition phases (the listening and learning states).
Port violation: what is it?
A feature of Cisco’s port security that blocks input to an interface when it receives a frame that violates the port security parameters for that interface is called the Cisco port security violation mode.
What dangers do ports face?
These dangers include acts of piracy, terrorism, the transportation of stowaways and illegal substances, the theft of goods and fraud, as well as bribery and extortion. The intricacy of the problems facing port security may be illustrated very well by the example of sea robbery.
How does a device get recognized by port security?
You are able to set each switch port with its own one-of-a-kind list of the MAC addresses of devices that are permitted to access the network through that particular switch port when you use Port Security. Because of this, individual ports are able to detect, thwart, and log any attempts made by unauthorized devices to communicate through the switch.
L2 security: what is it?
The threat that is aimed at disabling the network or compromising network users with the intention of gleaning important information such as passwords is one of the most prevalent security risks in the Layer 2 domain. It is also one of the dangers that is least likely to be caught.
What distinguishes Layer 2 security from Layer 3 security?
A Layer 2 switch is only capable of working with MAC addresses and has no interaction with addresses from higher layers, such as an IP address. On the other hand, a Layer 3 switch is capable of both static and dynamic routing, which encompasses IP and virtual local area network (VLAN) communications. It can also execute both routing types simultaneously.
How should a switch port be set up?
Sometimes switch ports must manually have their duplex mode and speed manually configured.
Table 2-5 Cisco Switch Auto-MDIX Commands.
| Enter global configuration mode. | S1# configure terminal |
|---|---|
| Configure the interface to automatically negotiate the duplex mode with the connected device. | S1(config-if)# duplex auto |
How can a port on a Cisco switch be unblocked?
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- To the switch, connect.
- activate using the command.
- Run the terminal configure command.
- interface port-id to run (replacing port-id with the port you want to enable).
- Run “no shutdown” as a command.
- To save your changes, run “copy running-config startup-config”
What number of bits make up a MAC address?
MAC addresses have traditionally consisted of 48 bits of data. They are divided into two parts: the first 24 bits make up the Organizationally Unique Identifier (OUI), and the following 24 bits make up the serial number (formally called an extension identifier).
On a Cisco switch, how do I check the ports?
Entering the show port command without any parameters will give an overview of the information that is available for each port on the switch. If you know the number of a certain module, you may view information simply about the ports that are associated with that module. In order to view specific information on the port in question, you will need to enter both the module number and the port number.
A persistent MAC address: what is it?
Randomization that happens repeatedly
A permanent and randomly generated MAC address is produced by Android, and it is depending on the characteristics of the network profile, such as the SSID, security type, or FQDN (for Passpoint networks). This MAC address will not change unless the factory settings are reset.
How are MAC address tables utilized?
The switch keeps information about the other Ethernet interfaces on a network in a table known as the MAC address table. This table allows the switch to communicate with the other Ethernet interfaces. Instead of broadcasting the data on all of the switch’s ports, the table enables the switch to transmit outgoing data (Ethernet frames) on the precise port that is necessary for the data to reach its destination (flooding).
Why should switch trunk ports have port security enabled?
There is support for nonnegotiating trunks inside port security. –When you change the configuration of a secure access port such that it is used as a trunk, port security will convert all of the sticky and static secure addresses on that port that were dynamically learnt in the access VLAN into sticky or static secure addresses on the native VLAN of the trunk. –
What does port security mean by aging time?
When an authorized user is not currently online, the inactivity aging function prohibits any unauthorized users from making use of a protected MAC address. This functionality also eliminates insecure MAC addresses that have become obsolete, making it possible to either learn or establish new secure MAC addresses.
An BPDU frame is what?
Frames that carry information about the spanning tree protocol are called Bridge Protocol Data Units, or BPDUs for short (STP). A switch will issue BPDUs from its origin port to a multicast address using a destination MAC address and a source MAC address that is unique to the switch (01:80:C2:00:00:00, or 01:00:0C:CC:CC:CD for Cisco proprietary Per VLAN Spanning Tree).
A BPDU packet is what?
Detecting loops in network topologies is the purpose of a data message known as a bridge protocol data unit (BPDU), which is sent across a local area network (LAN). A BPDU will have information about its ports and switches, as well as port priority and address information. The information that is required to configure and maintain the spanning tree topology is included inside BPDUs.
What VLAN is accurate?
Which of the following statements about virtual local area networks (VLANs) is true? All Virtual Local Area Networks (VLANs) are setup on the switch with the highest throughput, which then propagates this information to the remaining switches. VTP is what’s utilized to convey information about VLANs to switches that are part of a VTP domain that’s been setup. There should not be more than ten switches in a single VTP domain at any given time.
Do VLANs require IP addresses?
This is due to the fact that each Virtual Local Area Network (VLAN) functions as its own distinct broadcast domain, which necessitates a different IP address and subnet mask. The switch does not require a default gateway IP address, however having one is highly recommended.
Is port 80 a security hole?
An adversary who gained network access to the web server on port 80/TCP or port 443/TCP would have the ability to execute commands on the system with administrative rights. An unauthenticated attacker that has access to the network where the affected service is hosted and might potentially exploit the security vulnerability.
Which ports are at risk?
Common vulnerable ports include:
- FTP (20, 21) (20, 21)
- SSH (22) (22)
- Telnet (23) (23)
- SMTP (25) (25)
- DNS (53) (53)
- Over TCP and NetBIOS (137, 139)
- SMB (445) (445)
- HTTP/S and HTTP (80, 443, 8080, 8443)
Why do ports lock?
Port security keeps an eye on both the received and the learned packets that are sent across certain ports. Users with certain MAC addresses are the only ones who can access ports that have been locked. There are two different modes for Port Security. Classic Lock prevents the port from learning any new MAC addresses and locks all previously learnt MAC addresses on the port. This option locks all MAC addresses on the port.
What purpose does MAC filtering serve?
Through the use of MAC address filtering, you are able to prevent traffic from particular machines or other devices from entering your network. A computer or other device on the network may be identified by the router using its MAC address, and access can either be denied or granted accordingly. The policy will determine whether or not any traffic that originates from a certain MAC address will be filtered.
What accomplishes ARP spoofing?
An ARP spoofing attack is carried out when a hacker manipulates one device to transmit communications to the hacker rather than the receiver to whom the messages were supposed to be sent. The hacker will have access to the communications of your device, including sensitive data such as passwords and credit card information, after they have done this.
What dangers exist to LAN security?
LAN Security Threats
- Viruses. Generally speaking, viruses do not pose a “security” risk to the computers on your LAN (although they can cause plenty of problems).
- Attachments to emails.
- Probes.
- False horses.
- 3/18/00 Worms.
- worm called “netlog”.
What is security at Layer 3?
The Layer 3 approach to network security creates an efficient strategy for network security management by taking into account the entirety of the network, which includes edge devices (such as firewalls, routers, web servers, and anything else that provides public access), endpoints (such as workstations), as well as devices that are connected to the network, such as mobile phones.
On switches, what Layer 2 security method is used?
Implementing the Port Security function will stop unauthorized users from gaining access to switching ports. When it is necessary to divide network traffic at Layer 2, use the Private VLAN capability where it is available. When it is appropriate, use the MD5 authentication method.
What distinguishes an L2 VLAN from an L3 VLAN?
I responded to them by stating that a Layer 2 VLAN has just one broadcast domain. It operates properly on layer 2 (Datalink Layer). They are only able to converse with one another within it. The L3 virtual local area network (VLAN) interface operates on the network layer.
a VLAN Layer 2 or Layer 3?
The Internet Protocol (IP) subnets are examples of network layer (OSI layer 3) constructions, whereas virtual local area networks (VLANs) are examples of data link layer (OSI layer 2) constructs. Although it is possible to have numerous IP subnets on one VLAN, it is common practice for there to be a one-to-one relationship between IP subnets and VLANs in a setting that makes use of virtual local area networks (VLANs).
What is Cisco’s standard ARP timeout?
The default value for the ARP cache timeout in the Cisco IOS® software is four hours (240 minutes), although this value may be changed in the interface configuration mode. The default value can also be changed.
How can I determine a table’s MAC address?
Utilizing the show mac-address-table command while in privileged EXEC mode will allow you to view information on the MAC address table. Displays the number of entries that are currently present in the MAC address table (this feature is optional). When none of the available parameters are supplied, the command will display the complete MAC address database.
On a switch, how many ports are there?
Count of available ports
Fixed-configuration switches often come with five, eight, 10, 16, 24, 28, 48, or 52 ports. Other possible port counts include 16, 24, 28, and 48.
What is the Cisco switch’s default IP?
The IP address of the switch is set to 192.168 by default when it was manufactured. 1.254 by default.
Why is port error turned off?
The Errdisable error disable feature’s primary function is to provide the administrator with notification if there is a problem or issue with a port. There are a lot of different things that might cause a catalyst switch to enter Errdisable mode and shut down a port, one of which is a duplex mismatch. Loopback Error.
Can switches shut down ports?
The fact that ports are a layer 4 (TCP or UDP) function makes them invisible to switches; hence, a pure switch would be unable to prevent ports from being used.
A static IP address: what is it?
IP addresses that do not change.
Your computer is only identifiable to the rest of the Internet by its IP address if it is serving as a web server for another website. A machine connected to the Internet may have either a static IP address, which indicates that the address will not change over time, or a dynamic IP address, which indicates that the address may vary over time.
Two devices sharing the same IP address is possible.
Every single public IP address that is given out to routers that are connected to the Internet or to ISP routers is one of a kind. However, the private IP addresses of two different hosts might be the same even though they are linked to separate public networks. Your device may therefore be uniquely identified by using both its public and private IP addresses.