Description

Experts in the field have prepared all Cisco CCNA 200-301 certification exam dumps, study guides, and training courses. The 200-301 Cisco Certified Network Associate (CCNA) practice test questions and answers provided by Allrecentdumps, along with exam dumps, study guides, and training courses, make studying and passing the exam a breeze!

How long a Packet 1 lasts Introduction In this section, we will examine a packet’s lifespan. Therefore, you will gain knowledge of the process by which a packet travels from the source to the destination as well as everything that takes place on our hosts, switches, and routers to accomplish this. Therefore, we will begin by discussing a few of the protocols that assist the source in determining the route to the destination; that is the address resolution protocol (ARP) and the domain name system (DNS). You will have all the information you need to comprehend IP networking once we have covered those. In addition, we will demonstrate the complete life cycle of a packet, beginning at the origin and continuing all the way to the destination, as well as the various components that cooperate with one another to make this possible. Everything else—all of the lectures we’ve covered up to this point—comes to a close in this section. Therefore, it is a substantial section. You should have a solid understanding of the fundamentals of IP networking by the time we are finished.

2. In this lecture, you will learn about DNS, or the domain name system. Therefore, we are once more in the OSI stack here. Additionally, the packet starts at layer seven when a sender composes. That data is stored there by the application layer. That is then encapsulated by the information from the presentation layer and the information from the session layer. When we get down to layer four, we begin to become interested in working as network engineers. The packet’s transport layer will be encapsulated by the layer 4 header, which contains details such as “Is it TCP or UDP?” and the port number, such as port 84, which handles HTTP web traffic. The IP header, which is the layer-3 header, is then used to encapsulate that.

The sender is also required to provide the IP addresses of the source and destination on that layer. While it may use an FQDN, or fully qualified domain name, such as www.cisco.com, in some applications it may actually include the IP address directly. Additionally, we must resolve that FQDN to an IP address that we can include in the packet. DNS plays a role in this situation. That fully qualified domain name, such as www.cisco.com, is routed through the domain name system to an IP address. The IP addresses of internal hosts will typically be resolved by an enterprise’s internal DNS server or cluster of internal DNS servers. If I were employed by a company called Flatbox.com, for instance, we would have our very own internal DNS server, which would be in charge of resolving all of the hosts that were part of the Flatbox.com domain. However, that internal DNS server cannot be privy to all Internet information.

The entire database cannot be stored there. It will therefore need to forward those requests to an external public DNS server for anything external. UDP port 53 is used to send DNS requests, which can fail over to TCP on port 53, but typically uses UDP. Therefore, let’s examine DNS in the laboratory. I’m going to open a command prompt here in order to accomplish that. I’ll run an Ipconfig on everything since this is on my hostile entry command for Windows. On the interface I’m using for the lab, you can also see that my IP address is one 7223 110, or 24. Furthermore, my default gateway router is located at 107 223-1254. One seven-two dot 23 dot four dot one is where my DNS server is located. Additionally, I am a member of the dot lab Flatbox DNS domain. Therefore, let’s move on to the DNS server. As my DNS server, I’m using a Windows server. Therefore, let’s investigate Server Manager.

You can see that the server here is the authority for the domain flatboxa lab by clicking Tools and then opening upDNS. You can also see that I have already established address records for a few hosts there if I click on that. Therefore, Linuxa is at 172,234 and the hostengineeringa is at 611; etc. Additionally, they are all part of the flagboxa.lab domain. For configuration purposes, this DNS server would need to forward a request for an FQDN from a different domain to public DNS. I have no configured forwarders if I right-click on the server in the top left corner and select Properties and Forwarders. However, I could edit this and enter the IP address of a public DNS server. That concludes the DNS configuration. If I go back to my local host and do an NS lookup for Linuxa’s host, you can see that it takes a moment. After that, my DNS server, which is 172 23 4 1, has resolved Linuxa flatbox a lab to 172 23 4 2. Additionally, Linuxa was able to resolve the issue, so when I ping it, the ping works perfectly. Therefore, I will be able to ping that host using either its IP address, host name, or FQDN. Okay, DNS works that way in a Windows environment. After that, they examine DNS on our Cisco routers.

3. DNS on Cisco Routers The commands to make a router a DNS client. If you want the router to be able to resolve FQDNs, you would do this. As an illustration, you would need to set up a DNS client if you wanted to ping Linuxa from the router. For DNS traffic to pass through the router, you no longer need to configure it as a DNS client. This only applies if you frequently require the router to be able to resolve sqdns to host names. When we’re working on a router, we won’t do that often; We will always use IP addresses in our work.

However, if you wanted it to be able to resolve host names, you would need to enter the IP domain lookup, IP name server, IP domainname, and then the primary domain name commands. This will enable it to look up a DNS server. Also, this is how you set it up to be a DNS client if you want it to look up additional DNS suffixes, an IP domain list, and then those additional suffixes. You would enter the same commands to configure a router as your DNS server if you wanted one. plus, a command that makes it a DNS server is IP DNS Server. Then, for everything you want it to be able to resolve, you would have to enter address records. The command for that is “IP host,” followed by the host’s name and IP address. A Cisco router will typically not be used as a DNS server.

To do that normally, you would use an external Windows, Unix, or Linux server, but it can. Okay, so those were the instructions. Let’s set that up in the lab. I’ll look at the lab classification next. First. As can be seen, I have three routers: R, R1, R2, and R 3. One of them has the IP address 1010. 1010 two is R two. It also has a 1010, 22 interface, and our three is at 1010, 21. I’m going to set R3 up as the DNS server, and I’m going to add entries there for each of the three routers so it can find them. After that, we’ll set one up to be the DNS client. Okay, so I have both routers’ windows open. First, let’s set up the DNS server, which was our third step. I’ll execute a show IP interface brief to immediately verify the IP addresses. Yes, that will be our DNS server: 1010-21. To enable it to use DNS, I will therefore enter IP domainlook up first. Additionally, I skipped Global Configuration. Therefore, before proceeding to Global Configuration, configure, IP domain lookup ought to function. The IP nameserver, located at 1010-21, is the next step in configuring the DNS server’s location.

After that, I’ll set up the domain name. Therefore, the IP domain name. I will also use FlatBox Lab for this lab. The only difference between this and the Windows lab I showed you is that I’m working on my Cisco router now. “ipdns server” is the command to make this the DNS server. These are then my fundamental DNS commands. Entering the addresses of the hosts I want to resolve is the next step. “IP host” is the command for that. R 1, which is located at 1010 1, is the first one. R 2 will come next. For this, I’ll use the command history. I’ll therefore press the up arrow to retrieve the previous command. Additionally, in order to render it opaque, I will edit this using the cursor keys. Is R2 1010, followed by the up arrow once more? R three is the next host, and its address is 1010 21. As a result, let’s say you host. In order to demonstrate how to do that, I’ll also enter these as FQDNs. R two is at 1010 two, and IP host R one dot flatbox dot lab is at 1010 one.

I simply use the up arrow once more there. Additionally, I will edit this to include the correct IP address and R two-dot flatbox dot lab. Iphostr threeflatbox lab is located at 1010, 21 in the final one. That concludes the configuration for my DNS server that I require. Let’s set up R1 to be a DNS client next. To enable it to use a DNS server, I’ll enter here, select global configuration, and then IP domain lookup. The IP name server should then be set to be where the DNS server is. That is on our three, which is located at 1010 and 21. The DNS suffix, or IP domain list flatbox lab, comes next. Let’s see if I can now resolve host names on R one if I use end to return to the enable prompt. I’ll therefore try pinging R3 using its host name. It then resolved that, and I can see that the success rate was five out of five. I can also see that it is resolving it at the domain server at 1010 21. That appears to be fine. Try pinging R two as well. As a result, the DNS server will also resolve this to 1010, dot 1, and it did so to 1010, dot 2, which I was able to ping as well. On your Cisco routers, you configure DNS in this manner. The next lecture will focus on art as our next topic.

Experts in the field have prepared all Cisco CCNA 200-301 certification exam dumps, study guides, and training courses. The 200-301 Cisco Certified Network Associate (CCNA) practice test questions and answers provided by Allrecentdumps, along with exam dumps, study guides, and training courses, make studying and passing the exam a breeze!

How long a Packet 1 lasts Introduction In this section, we will examine a packet’s lifespan. Therefore, you will gain knowledge of the process by which a packet travels from the source to the destination as well as everything that takes place on our hosts, switches, and routers to accomplish this. Therefore, we will begin by discussing a few of the protocols that assist the source in determining the route to the destination; that is the address resolution protocol (ARP) and the domain name system (DNS). You will have all the information you need to comprehend IP networking once we have covered those. In addition, we will demonstrate the complete life cycle of a packet, beginning at the origin and continuing all the way to the destination, as well as the various components that cooperate with one another to make this possible. Everything else—all of the lectures we’ve covered up to this point—comes to a close in this section. Therefore, it is a substantial section. You should have a solid understanding of the fundamentals of IP networking by the time we are finished.

2. In this lecture, you will learn about DNS, or the domain name system. Therefore, we are once more in the OSI stack here. Additionally, the packet starts at layer seven when a sender composes. That data is stored there by the application layer. That is then encapsulated by the information from the presentation layer and the information from the session layer. When we get down to layer four, we begin to become interested in working as network engineers. The packet’s transport layer will be encapsulated by the layer 4 header, which contains details such as “Is it TCP or UDP?” and the port number, such as port 84, which handles HTTP web traffic. The IP header, which is the layer-3 header, is then used to encapsulate that.

The sender is also required to provide the IP addresses of the source and destination on that layer. While it may use an FQDN, or fully qualified domain name, such as www.cisco.com, in some applications it may actually include the IP address directly. Additionally, we must resolve that FQDN to an IP address that we can include in the packet. DNS plays a role in this situation. That fully qualified domain name, such as www.cisco.com, is routed through the domain name system to an IP address. The IP addresses of internal hosts will typically be resolved by an enterprise’s internal DNS server or cluster of internal DNS servers. If I were employed by a company called Flatbox.com, for instance, we would have our very own internal DNS server, which would be in charge of resolving all of the hosts that were part of the Flatbox.com domain. However, that internal DNS server cannot be privy to all Internet information.

The entire database cannot be stored there. It will therefore need to forward those requests to an external public DNS server for anything external. UDP port 53 is used to send DNS requests, which can fail over to TCP on port 53, but typically uses UDP. Therefore, let’s examine DNS in the laboratory. I’m going to open a command prompt here in order to accomplish that. I’ll run an Ipconfig on everything since this is on my hostile entry command for Windows. On the interface I’m using for the lab, you can also see that my IP address is one 7223 110, or 24. Furthermore, my default gateway router is located at 107 223-1254. One seven-two dot 23 dot four dot one is where my DNS server is located. Additionally, I am a member of the dot lab Flatbox DNS domain. Therefore, let’s move on to the DNS server. As my DNS server, I’m using a Windows server. Therefore, let’s investigate Server Manager.

You can see that the server here is the authority for the domain flatboxa lab by clicking Tools and then opening upDNS. You can also see that I have already established address records for a few hosts there if I click on that. Therefore, Linuxa is at 172,234 and the hostengineeringa is at 611; etc. Additionally, they are all part of the flagboxa.lab domain. For configuration purposes, this DNS server would need to forward a request for an FQDN from a different domain to public DNS. I have no configured forwarders if I right-click on the server in the top left corner and select Properties and Forwarders. However, I could edit this and enter the IP address of a public DNS server. That concludes the DNS configuration. If I go back to my local host and do an NS lookup for Linuxa’s host, you can see that it takes a moment. After that, my DNS server, which is 172 23 4 1, has resolved Linuxa flatbox a lab to 172 23 4 2. Additionally, Linuxa was able to resolve the issue, so when I ping it, the ping works perfectly. Therefore, I will be able to ping that host using either its IP address, host name, or FQDN. Okay, DNS works that way in a Windows environment. After that, they examine DNS on our Cisco routers.

3. DNS on Cisco Routers The commands to make a router a DNS client. If you want the router to be able to resolve FQDNs, you would do this. As an illustration, you would need to set up a DNS client if you wanted to ping Linuxa from the router. For DNS traffic to pass through the router, you no longer need to configure it as a DNS client. This only applies if you frequently require the router to be able to resolve sqdns to host names. When we’re working on a router, we won’t do that often; We will always use IP addresses in our work.

However, if you wanted it to be able to resolve host names, you would need to enter the IP domain lookup, IP name server, IP domainname, and then the primary domain name commands. This will enable it to look up a DNS server. Also, this is how you set it up to be a DNS client if you want it to look up additional DNS suffixes, an IP domain list, and then those additional suffixes. You would enter the same commands to configure a router as your DNS server if you wanted one. plus, a command that makes it a DNS server is IP DNS Server. Then, for everything you want it to be able to resolve, you would have to enter address records. The command for that is “IP host,” followed by the host’s name and IP address. A Cisco router will typically not be used as a DNS server.

To do that normally, you would use an external Windows, Unix, or Linux server, but it can. Okay, so those were the instructions. Let’s set that up in the lab. I’ll look at the lab classification next. First. As can be seen, I have three routers: R, R1, R2, and R 3. One of them has the IP address 1010. 1010 two is R two. It also has a 1010, 22 interface, and our three is at 1010, 21. I’m going to set R3 up as the DNS server, and I’m going to add entries there for each of the three routers so it can find them. After that, we’ll set one up to be the DNS client. Okay, so I have both routers’ windows open. First, let’s set up the DNS server, which was our third step. I’ll execute a show IP interface brief to immediately verify the IP addresses. Yes, that will be our DNS server: 1010-21. To enable it to use DNS, I will therefore enter IP domainlook up first. Additionally, I skipped Global Configuration. Therefore, before proceeding to Global Configuration, configure, IP domain lookup ought to function. The IP nameserver, located at 1010-21, is the next step in configuring the DNS server’s location.

After that, I’ll set up the domain name. Therefore, the IP domain name. I will also use FlatBox Lab for this lab. The only difference between this and the Windows lab I showed you is that I’m working on my Cisco router now. “ipdns server” is the command to make this the DNS server. These are then my fundamental DNS commands. Entering the addresses of the hosts I want to resolve is the next step. “IP host” is the command for that. R 1, which is located at 1010 1, is the first one. R 2 will come next. For this, I’ll use the command history. I’ll therefore press the up arrow to retrieve the previous command. Additionally, in order to render it opaque, I will edit this using the cursor keys. Is R2 1010, followed by the up arrow once more? R three is the next host, and its address is 1010 21. As a result, let’s say you host. In order to demonstrate how to do that, I’ll also enter these as FQDNs. R two is at 1010 two, and IP host R one dot flatbox dot lab is at 1010 one.

I simply use the up arrow once more there. Additionally, I will edit this to include the correct IP address and R two-dot flatbox dot lab. Iphostr threeflatbox lab is located at 1010, 21 in the final one. That concludes the configuration for my DNS server that I require. Let’s set up R1 to be a DNS client next. To enable it to use a DNS server, I’ll enter here, select global configuration, and then IP domain lookup. The IP name server should then be set to be where the DNS server is. That is on our three, which is located at 1010 and 21. The DNS suffix, or IP domain list flatbox lab, comes next. Let’s see if I can now resolve host names on R one if I use end to return to the enable prompt. I’ll therefore try pinging R3 using its host name. It then resolved that, and I can see that the success rate was five out of five. I can also see that it is resolving it at the domain server at 1010 21. That appears to be fine. Try pinging R two as well. As a result, the DNS server will also resolve this to 1010, dot 1, and it did so to 1010, dot 2, which I was able to ping as well. On your Cisco routers, you configure DNS in this manner. The next lecture will focus on art as our next topic.