This document will have a focus on understanding and preventing the arp poisoning also known as the maninthemiddle mitm layer 2 attack on the cisco catalyst 6500 switching series switch running cisco ios software. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Switch based network are layer 2 networks, this lead to an inside network attack risk. Still another example is when an attacker targets a download on a website and proceeds to go through the process i just described above. Network layer attacks tcpip layer 2 osi layer 3 to create a network layer dos attack, most attackers pound a target network with more data than it can handle. Dec 14, 20 for example, some types of layer 7 ddos attacks will target website elements, like your logo or a button, and repeatedly download resources hoping to exhaust the server. The processes of transmitting packets on a given link layer and receiving packets from a given link layer can be controlled both in the software device.
Layer 3 attacks layer 3 attacks and mitigation a router. Falling behind, the target network begins to slow and drop packets, which may or may not cause a flood of retransmission requests. Layer 34 attacks rely on sending more traffic than the server can handle. Attacks in layer 2 are valuable because they require no prior information about a sheep, a network, etc. Layer 3 attacks layer 3 attacks and mitigation a router is. Common layer 2 attacks my journey into network security. Therefore you might better refer to the tcpip model which merges osi layer 57 into a single application layer and dont look for separate attacks at each of these layers. Rethinking the division of labor by nir solomon final project submitted in partial fulfillment of the requirements for the m. If an initial attack comes in at layer 2, the whole network can be compromised. Layer 3 attacks and mitigation a router is a network device that routes ip packets across computer networks. Tools for attacking layer 2 network infrastructure kaihau yeung, dereck fung, and kinyeung wong proceedings of the international multiconference of engineers and computer scientists 2008 vol ii.
This paper discusses several methods that result in packet sniffing on layer 2 switched networks. The physical layer layer 1 sits at the bottom of the open systems interconnect osi model,and is designed to transmit bit streams using electric signals,lights, or radio transmissions. Yeung, fung, and wong 2008 enumerated several of the different tools used to implement layer 2 attacks. Netbios and llmnr resolution are rarely required, and can almost always be disabled to stop these attacks, while arp spoofing can be detected or prevented by network devices, and malicious wireless network threats. This requires stripping off the datalink layer frame information.
Internetwork layer application transport internetwork link physical 7 4 3 2 1 bridges multiple subnets to provide endtoend internet connectivity between nodes provides global addressing ip addresses only provides besteffort delivery of data i. Layer 3 protocols are commonly referred to as the i protocols, though this isnt completely accurate, it suffices for the scope of the. Layer 3 and layer 4 ddos attacks layer 3 and layer 4 ddos attacks are types of volumetric ddos attacks on a network infrastructure layer 3 network layer and 4. This tutorial will teach you some of the important security measures to secure your network for layer 2 attacks by following some of the best security practices. When it comes to networking, layer 2 can be a very weak link physical links mac addresses ip addresses protocolsports application stream application presentation session transport network data link physical. Also, logical diagrams are in many cases more valuable than.
Layer 2 attacks and their mitigation louis senecal. A router works with ip addresses at layer 3 of the model. It is the gateway to the servers where your application resides. Preventing layer 2 attacks these days the ethernet switches have literally replaced the shared media hubs especially in the large corporations. All layers of tcpip has got its own security threats and vulnerabilities. Introduction this memorandum aims to describe the list of security threats and counter measure that might be identified on an 802.
Layer 2 security measures mentioned in this chapter go a long way towards protecting a network from many types of attacks. Objectives assign the central switch as the root bridge. The ability and usefulness of the ethernet switch lies in its ability to memorize the mac address of each of the ports connected to it, so that any frame which enters the switch, can be. L3 diagrams are vital for troubleshooting or for planning changes. We were tired of doing always the same layer 2 attacks arp poisoning, cam flooding. The method of dividing a single layer 2 network to multiple broadcast domains so that traffic of those different broadcast domains flow independently without colliding each other in that same layer 2 network is called virtual local area networksvlan. Contribute to tomacyersinia development by creating an account on github. Overview application layer dos attacks are evolving as part of the evolution of application attacks the denied service is the application itself rather than the host effectively preventing usage of the system. If you continue browsing the site, you agree to the use of cookies on this website.
The vrrpadm showrouter command shows the configuration and status of a specified vrrp router. Attacks at the data link layer university of california, davis. Enable port security to prevent cam table overflow attacks. These include mac spoofing, layer 2 broadcast storms, and attacks on the switching layer for instance vms speaking spanningtree protocol and confusing the switches.
Demystifying layer 2 attacks abhishek singh, cissp communication unit of ethernet layer 2 referred to as layer 2 in rest of paper is frame and is fig fig 1. Applying security policies to network switches deniz kaya microsoft, cisco, ironport trainer ccsi, ccnp, mct, mcse, icsi, icsp. Layer 3 protocols are commonly referred to as the i protocols, though this isnt completely accurate, it suffices for the scope of the cissp exam. Layer 7 ddos attack a layer 7 ddos attack is an attack structured to overload specific elements of an application server infrastructure. Notice that the bottom layer is identified as the first layer.
Layer 7 attacks are especially complex, stealthy, and difficult to detect because they resemble legitimate website traffic. The link layer, which is the method used to move packets from the network layer on two different hosts, is not really part of the internet protocol suite, because ip can run over a variety of different link layers. Understanding, preventing, and defending against layer 2 attacks. Rfc 7348 virtual extensible local area network vxlan. If youre responsible for securing a corporate or private network, you need to be aware of the vulnerabilities that attackers will use. To illustrate the weakness of layer 2 networks, attacking tools for this layer are. Arp cache poisoning, cam table flooding, and switch port. In an ip layer 3 network, the ip portion of the datagram has to be read.
Securing the network layer is the only way to ensure your application is not flooded with attacks which could be easily blocked at that outermost layer. Securing the network layera secure network is a web applications first line of defense against malicious attacks. Layer 2 attacks and mitigation techniques apnic 29. The actual protocols encompassed in the link layer are numerous, and the implementation details can be found in various documents throughout the internet and in trade texts. Based on the destination and source ip addresses, the router decides to which network device it will forward the packet. Each mac address is a unique series of numbers, similar to serial numbers or lan ip addresses. Securing the network layer against malicious attacks tdk. Because layer 2 information unique identifiersmac addresses provides the most basic foundations of a communication system, this information is not private or encrypted in fact it is publicly broadcast. Switch security attacks are the most popular topic in the switch layer 2 security. Further, the larger the layer 2 network, and the less trusted the participants, the greater the likelihood of layer 2 problems occurring. Wright red hat august 2014 virtual extensible local area network vxlan. Destination address ethernet address of the destination host, 48bits 3.
I am going to setup the following security measures bpdu guard, root guard and port security and use the kali linux box in my topology to launch attacks fun times. Layer 2 attacks are timeworn but still relevant in todays networking. Join timothy pintello for an indepth discussion in this video, understanding layer 3. There have been a number of attacks on the network recently. This chapter discusses layer 2 attacks, mitigations, best practices, and functionality.
The biggest single problem im seeing when working on enterprise networks is the lack of l3 logical network diagrams. A layer 7 ddos attack is a sophisticated form of distributed denial of service that attacks the application layer of the osi model. In addition to the ip addressing protocol at layer 3, there is theip helper protocol icmp and its various messages that are used by networking diagnostic utilities such as ping and traceroute. However, all of the tools rely on the lack of proper authentication during layer 2. Network attacks, part 1 university of california, berkeley. Understanding, preventing, and defending against layer 2. Note that this list of tools can launch all known layer 2 a tck su m r iz ed ntb li h oy p u th er gncy ad s if l 2 k problem. We will be discussing security threats and vulnerabilities in each and every layer in tcpip separately in different posts as each one requires special attention. Data link layer, layer 2 in the tcpipbased layered network, layer 2 is the data link layer. Chapter 1 introduction to networking and the osi model. The main functionalities appear to be file uploads, persistence, and ddos traffic floods. When a packet arrives at a router, the router inspects the ip header of the pac.
Displaying layer 2 and layer 3 vrrp router configurations. As the title of this section implies, we look exclusively at the protocols at layer 3 and the multitude of threats targeting them. Review some attacks that can occur in the data link layer or layer 2, such as stp attack, arp and mac spoofing, vlan hopping attacks, and dhcp attacks. Before learning about configuring switches for security improvements, let us take a look at some of the types of attacks to which these layer 2 switches are vulnerable as that would lay the foundation for studying further. When it comes to networking, layer 2 can be a very weak link.
Rather than simply flooding a network with traffic or sessions, these attack types target specific applications and services to slowly exhaust resources at the application layer layer 7. In the networking world in general this is also one of the most exciting and dynamic topic of all. A framework for overlaying virtualized layer 2 networks over layer 3 networks abstract. Topic 6, common layer 2 attacks flashcards quizlet.
Within the discussion of content networking, we will. How to draw clear l3 logical network diagrams packet pushers. Network layer attacks tcpip layer 2osi layer 3 to create a network layer dos attack, most attackers pound a target network with more data than it can handle. Layer 3 networks are built to run on on layer 2 networks.
A manufacturer should not have two devices with the same mac address. My sincere apologies to those unable to get into the class. Cisco device security is surely one of the most interesting topics in the whole cisco world. All attacks and mitigation techniques assume a switched ethernet network running ip if it is a shared ethernet access wlan, hub, etc most of these attacks get much easier if you are not using ethernet as your l2 protocol, some of these attacks may not work, but chances are, you are vulnerable to different types of attacks. Layer 2 switching attacks and mitigation from networker, december 2002 1.
Most of the time im facing situations where a customer doesnt have any logical network diagrams to give. Layer 2 attacks and mitigation techniques for the cisco. Pdf exploring layer 2 network security in virtualized. Packet sniffing on layer 2 switched local area networks. C h a p t e r 14 mitigating layer 2 attacks unlike hubs, switches cannot regulate the. Attacks at the data link layer abstract intrusion detection systems usually operate at layer 3 or above on the tcpip stack because layer 2 protocols in local area networks are trusted. Next, she addresses layer 2 attacks and techniques to secure cisco switches.
We were tired of check that, very often, routers and switches configuration are poorly set up and rarely hardened. Exploring layer 2 network security in virtualized environments. A layer 3 switch is a highperformance device for network routing. Mar 11, 2009 layer 2 security and attacks adam march 11, 2009 march 11, 2009 comments this tutorial will teach you some of the important security measures to secure your network for layer 2 attacks by following some of the best security practices. Lisa bock, a security ambassador, explains the difference between the control, data, and management planes in networking, and provides to an overview of layer 3 attacks and techniques for securing cisco routers.
Cyber ops 3des aes amplification arp asa asav asdm cam port security layer 2 mac cia cisco clientless cybersecurity ddos des dhcp dhcp snooping lab errdisable fping ike ipsec kali linux layer 2 attacks mac malware md5 sha missingroute nat networking basics network mapper network mapping ngfw nmap os fingerprint osi model paloalto panos. Application layer attacks use far more sophisticated mechanisms to attack your network and services. Presentation application session transport network data link physical layer 7 layer 6 layer 5 layer 4 layer 3 layer 2 layer. When a packet arrives at a router, the router inspects the ip header of the packet. Security issues addressed in this session include arp spoofing, mac flooding, vlan hopping, dhcp attacks, and spanning tree protocol concerns. Even simple layer 7 attacks for example those targeting login pages with random user. When it comes to networking, layer 2 can be a very weak link physical links mac addresses ip addresses. For this reason, it makes sense to limit the number of mac addresses within each cam table whether the cam table size.