From the course: CompTIA Network+ (N10-009) Cert Prep

Networking appliances

From the course: CompTIA Network+ (N10-009) Cert Prep

Start my 1-month free trial Buy for my team

Networking appliances

“

- There are several different hardware and software devices and applications used on a network, not just big networks, although they tend to have more and bigger devices, but also on small office and home office networks as well. In this video, we look at the primary network devices and in a few cases they're virtual equivalents, some applications, and a whole lot of network jargon. So let's start off with the physical and virtual appliances you need to know for the Network plus exam. The first device we'll look at is going to be the router. What router does is it routes. So routers operate on the network level of the OSI model, and they perform the amazing task of moving network packets from the source device to the destination device. While the function of a router can be somewhat complicated, in later episodes of this series, you will be instructed on how some of these actually work and how complicated it is, but for the time being, let's keep it simple. When you mail a letter, you know snail mail, you must include a destination address, including its routing code, AKA a zip code. Well, the zip code is initially important because it tells the post office the general location that it's intended to go to for the recipient. The digits in the code represent a zone in the country, a processing center within that zone, and the postal carrier route. So what's this got to do with the router? Well, a router uses IP, internet protocol addresses in much the same way that a letter is going to use a zip code. While IPV4 and IPV6 are handled differently as addressing goes, IP addresses in general contain the address of the network and the actual destination host. Much like a zip code with a city, a state, and a postal mail. A router is able to extract the network address from the destination address of a packet and forward it on to the next router in the path that it needs to reach. Routers keep a table of potential routes based on information shared by other routers or its own experience. The process is used to extract network identity from an IP address. Both IPV4 and IPV6 are covered later in this section. But what if the message that is forwarded isn't something the destination network wants to receive? You know, that's a good question. A firewall is a hardware or software device that creates a security gate and guards that entry into a network. Firewalls examine and filter incoming and outgoing network traffic using rules on an organization's security policy. Much like how a locked door prevents someone from just walking into your home, a firewall can prevent a malicious or unwanted network intruder from getting inside or any type of network traffic from actually entering or leaving your internal network. Other types of protective security devices include those that detect or prevent bad stuff from affecting a network. These devices are intrusion detection systems, otherwise known as IDS or intrusion prevention systems, otherwise known as IPS. These two function can also be contained inside of hardware or software intrusion detection and prevention systems. IDPS systems would be what that would be called. And intrusion prevention attempts to live up to its name, meaning that its purpose is to examine incoming or outgoing network traffic and to issue some type of security protocol on it so that if there's something that's detected that looks like it's malicious or at least suspicious, it's going to go ahead and stop it. So it's going to be protecting your network. And IPS is commonly deployed at the perimeter of a network as a supplement to a firewall, but it can also be a feature in a next generation firewall. And IPS uses either signature based or statistic anomaly detection schemes to identify malicious content. Signatures are specific patterns such as a bite sequence, which identify malicious threats. Anomaly based means that it's going to be looking for a random sample of packets and how things usually look as a baseline. Well, that's going to be a compass to understand if something is deviating. Anything that deviates from the baseline or what is considered as safe sets off an alert and IDS monitors and activates on the network or system in real time looking for anything unauthorized, suspicious, or downright malicious. It creates an alert and IDS is like a hall monitor looking for anything that shouldn't be in the hall at that time. Looking to see what's going on with the smoke detector, if there's any type of smoke or anything else that should be alerted to that is out of the norm. An IDS works similar to an IPS in that it compares data and collects against a baseline and sets alerts for anything deviating from that baseline. It also tracks changes made to key system settings, configurations and files that are unauthorized or suspicious. However, an IPS and IDS systems have some drawbacks. Although the good really overshadows the bad, false positives and false negatives can occur. A false positive is when it's determined that something safe and valid is actually malicious. A false negative is the opposite. Meaning that something malicious is determined to be safe and valid. Oh no, these systems can be configured around these issues and they can also learn and quickly adapt. Okay, so we filtered out any network traffic that would be possibly a harm to any our systems, but what can we do to protect the systems from any type of overload? I don't mean in a case like denial of service, which is what we're going to cover in a later video, but a steady stream of valid messages each with the request for information or a transaction to be processed. If the volume of incoming messages is more than one server can handle, we can add additional servers. But then we have the issue of distributing an incoming message to any available server. The solution is going to be to implement a process called load balancing. A load balancer is a hardware or software device that distributes incoming message traffic across two or more processing servers to provide a fast turnaround and tolerance for any type of faults that might actually happen on the system so that you don't have to deal with a system failure on a single system. A load balancer is often likened to a traffic cop or a dispatcher in that it balances out the processing of load of each of the servers in its cluster. Load balancers are commonly implemented in large data centers, content providers and cloud service domains. Another device that can help to reduce the load on a network is a proxy server. This is a service application that is a go-between for a request from a network user and the server local or remote that provides the response. In doing so, it can enhance the privacy, the performance, and security of the network. Requests from network users for files, web pages and the like go to the proxy server, which then either fills the request itself or sends the request to a resource server. It uses its identity for requests from resource servers, which hides that of the requesting node. On a growing network, data may be stored on individual computers and not easily accessed or shared. If the data is centralized on a file server, the volume of data and readily access to it might become an increasing problem, especially on a growing network. There are two ways that we can approach this problem. The network attached storage is going to be one. The other one is going to be a storage area network. We're going to refer to these as a NAS and a SAN. While they sound almost the same, they are very, very different, although they are similar. So let's start with network attached storage, the NAS. It is going to be as the name implies, data storage that is connected to a local area network and independent network node. A NAS provides centralized data storage capacity that network users can access and share. Typically, a NAS is going to be added to a network and it's going to be self-contained. A system on its own really with its own operating system, its own network interface, a storage area network though, a SAN is going to be a little bit different. It's going to be a purpose-built network of servers, storage devices, switches, software and supporting services that provide access to block level data to network users and devices. So a SAN is accessed from a local network and can include a disc array and different type of tape libraries that actually appear to be directly attached to a user's device. You should expect to encounter the devices we've covered in this video on the network plus exam. Know what each one does and what it's used for, as well as why. This is also something to note for a job interview as well.

Contents