OSPF setup in Cisco Packet Tracer. Router1 IP Configuration:

Laboratory work: Cisco Packet Tracer. Dynamic routing protocols (29.eleven.2018)

RIP-remote-vector protocol. Before performing laboratory work, download the Rip_file-Great File.Zip. For authentication on routers R1 and R2, use the name of the Admin user, for the instilled mode password 123, for the global configuration mode, password 123456.

Please note that packages follow the path R1. R2. It would seem a faster R1. R2. R2 route is ignored, although these are Fastethernet 100Mb/S channels. The path R1. R2 seems to be shorter, but this is the Ethernet 10MB/S channel. RIP defines the optimal path as the smallest number of hopes or intermediate routers. This is the lack of RIP protocol. OSPF protocol eliminates this drawback.

OSPF: Protocol of finding the shortest path

OSPF. Channel condition protocol. Before performing laboratory work, download the OSPF_File-Laboratory-Laboratory-Work file.Zip. For authentication on routers R1 and R2, use the name of the Admin user, for the instilled mode password 123, for the global configuration mode, password 123456.

Please note that the packages go along the seemingly longer R1. R3. R2 route. The fact is that these are FASTETHERNET 100MB/S channels. The path R1. R2 seems to be shorter, but this is the Ethernet 10MB/S channel. OSPF defines the optimal path taking into account the channel loading.

January 7, 2015. How to set up dynamic routing. OSPF on Cisco IOS

Want to know why Cisco dynamic routing is needed, how to configure OSPF on Cisco? Draw up to this article!

Let’s look at the next network topology:

Suppose we use static routing in this network, and there was a need to add a new router (R4). The routers “know” only about the networks connected to them directly (Directly Connected). In this case, we will have to manually add all the routes to the subnets on the R4, and on the rest of the routers add routes to the subnets served by R4:

With the growth of the network, this becomes a rather laborious task. Dynamic routing protocols make it possible to exchange routes automatically, simplifying the network maintenance. Also, the dynamic routing protocols themselves determine the optimal route for sending packages (we can influence this if necessary) and choose an alternative route in case of some channel falling.

For example, R3 can contact R1 through several routes: after, after ten.5.0.0/30 and ten.5.0.12/30. ten.5.0.0/30. When using OSPF, routers will constantly exchange information about well.known routes and the state of the connections. In the case of a direct channel falling between R1 and R3, traffic will go through a router R2.

OSPF setting

This is what the topology of our network with the added new router R4 will look like:

Let’s start by setting up the router R1. I represent your attention directly the example of setting.

The last number is a PID process, it may differ on different routers, but exclusively for convenience it is better to set the same number.

Now turn off the sending of Hello packages on all integrates. For security reasons, we will clearly set the intenses on which Neighbour Relations will be established.

Now we will indicate the integrates on which we will send Hello packages. For R1 it is FA0/0 and FA0/1:

Using the Network command, we can do 2 things. tell us which networks we want to announce on OSPF other routers and on what integrations we will send Hello packages. That is why we indicated specific integrates for Hello packages earlier. For example, on a router R1 we need 3 networks:, and But in the last network there will be exclusively user devices and we would not want someone to have the opportunity to influence the router routing tables.

The first parameter is the network number, the second is WildCart Mask and the last zone number.

Simply put, this team tells the router, from what integrations will be announced by OSPF subnets. In the example above, we allowed to announce any subnets, from any intenses. This method, of course, simplifies configuration, but not recommended Cisco. Because any integration that you set up on a router will immediately go into the routing tables for other routers. Cisco recommends connecting each network separately, for our network configuration, this will look like this:

To understand the syntax, I will give an example that will announce both official networks ( and

Literally, this means: “announced the subnets from the intenses that begin at 10.5.0 “

This means that R1 and R2 established Neighbor Relations and exchanged information about well.known routes. Now there should be one “neighbor” on R2:

From R1 we received 2 OSPF routes, which is what the letter O is talking about at the beginning of the route record.

Now our routing table looks like this:

Now you can try to simulate aplinka falls. Let’s trace the route from the R3 router to the client PC with IP

From trace it can be seen that traffic will go directly to R1. Disable the integration on R1, to which the R3 is connected:

Now traffic will go through an alternative channel (R3. R2. R1):

The OSPF setting with one zone (area 0) is completed on this. Now our network uses OSPF for dynamic routing.

OSPF Config on Router B

We Will Configure Router B Like Router A. We Will Enable OSPF and the Add OSPF Networks.

B (config)# Router OSPF 1 B (Config-Router)# Network 10.ten.eleven.0 Area 0 B (Config-Router)# Network 10.ten.12.0 Area 0 B (Config-Router) # Exit B # Copy Running-Config Startup-Config

OSPF Config on Router C

We Will Configure Router C Like Router A. We Will Enable OSPF and the Add OSPF Networks.

C (Config)# Router OSPF 1 C (Config-Router)# Network 10.ten.ten.0 Area 0 C (Config-Router)# Network 10.ten.12.0 Area 0 C (Config-Router)# Network 10.ten.13.0 Area 0 C (Config-Router)# End C# Copy Running-Config Startup-Config

Metric OSPF

We repeat once again, the metric in OSPF is called “price” (or value), then we will just call it COST. So Cost has each integration and is calculated according to the following formula:

OSPF COST = 100MBS/Bandwidth, where Bandwidth. Integeis throughput.

In fact, constant 100ms/s (megabit per second) matters by default and it can be changed. If it is not changed, the intenses that have throughput from 100ms and above will have the same Cost, equal to 1. Looking ahead, I can say that the COST value can be determined for each integer manually.

When all the routers exchanged information about their routes, they include SPF algorithm to determine the most “cheap” routes to recognized networks, t.e. Routes with the least COST value.

OSPF Link State Advertisements (LSA)

Very often it is this section that is a “stumbling block” for many beginner engineers. Let’s try to figure it out.

OSPF Routing Configuration with Multiple VLANs on Cisco Packet Tracer

Each router (of course, if the OSPF process is included in it) forms information about itself, it contains Router ID (RID) and Cost values. This information is called. Link State Advertisements (LSA). After “formation”, all routers exchange this information, so a table from the obtained LSA, which is called on each router, is formed on each router. Link State Database (LSDB). LSDB is formed for each area separately, so if the router is in the role of ABR (located on the border of several area), it has several LSDB tables, respectively for each area.

The foregoing some do not understand the above the first time, if you understand this the first time and think that you can describe it better. without hesitation, write to the author of this site!

  • If logical intenses are configured on the router, then RID determines how the largest IP address among these logical intenses. Otherwise the next step (if there are no Loopback integers).
  • The largest IP address is selected among active intenses.

Router2 IP and Interface Configuration:

Router#Conf T Router (Config) #HOSTNAME Router2 Router2 (Config) #int GigabitErnet 0/0 Router2 (config-maf) #ip Address 172.16.ten.2 router2 (config-maF) #NO Shut Router2 (Config-Fig) #EXIT Router2 (Config) #interface Gigabithernet 0/1 Router2 (Config-if) #IP Address 10.ten.22.1 router2 (config-ma) #NO Shutdown

Assign The IP Address, Subnet Mask, and Gateway. Is the Subnet Mask and Gateway Will Be the Next Hope Address of the Router or the Ip of Router-INTERFACETACED with PC, and in this case 192.168.44.one. Each Workstation Shoup Be Able to Ping the Attached Router.

Configure An Ospf Routing Process on All Routers. Use OSPF Process Number 1 and Ensure All Networks are in Area 0a. For configoring ANY Router with OSPF YOUNED To Advertise All the Directly Connected Networks in the OSPF Process. For Example, On Router0 You have the Networks and SO YOU CAN SEE I HAVE AdverTited Theres in Area 0 For OSPF Configuctions.

Router0#Conf T Router0 (Config) #router OSPF 1 Router0 (Config-Router) #NETWORK Area 0 Router0 (Config-Router) #NETWORK Area 0 Router0 (Config-Router) #Exit

Router1#Conf T Router1 (Config) #router OSPF 1 Router1 (Config-Router) #NETWORK 192.168.55.twenty.0.0.255 Area 0 Router1 (Config-Router) #NETWORK 172.16.ten.0 Area 0 Router1 (Config-Router) #Exit

OSPF Standard Area and Backbone Area On Cisco Packet Tracer

In this Lesson We Will Concentrate On Ospf Standard Area and Ospf Backbone Area. We Will Do a Multi Area OSPF Configuration with Backbone Area and Ospf Standard Areas. In Other Lesson, We Will Also Give Example for the Osspf Area Types and Their Configuration Examps on Packet Tracer.

You can download the Cisco Packet Tracket Tracer Example with Pkt Format at the End of this Lesson.

As you Know from the previous Lessons, OSPF HAS 6 Different Areas. These areas are:

  • Backbone Area
  • Standard (Normal) Area
  • Stub Area
  • Totally-STUB Area
  • Not-so-STUBBY Area (NSSA)
  • Totilla Not-So-Stubby Area

You can check the Below Lessons for the Configuration of Diffferent Ospf Area Types:

In this first post, We Will Focus on Backbone Area and Standard (Normal) Area. Beside this, We Will See the Configuration of Virtual-Link On Ospf. What Was The Virtual-Link? It Was The Link that Ussed to Connect the Normal Areas to the Backbone Area, If they Are not Directly to the Backbone Area. Remember, in OSPF, There WAS A RULE. All Areas Must Be Connected to the Backbone Area, Area 0. IF THEY ARE NOT, They Can Temporarily Connect to the Backbone Via Virtual-Links.

OSPF Backbone Area and Standard Area with Accepted Lsas Backbone Area Also A Normal Area But is Area 0aa 0.

Normal Areas Accept. They Accept Also The External LSAS (Type 5 LSAS). Type 1 and Type 2 LSA ALREADY Accepted Inside Area.

We Talked About Theorical too Much. This post aims to show you the configuration of thiss and as you know, doing the configuration is the most effective Way of Learning Network Protocoli.

OUR TOPOLOGY Will BE Like Fort Heart Example.

OSPF Backbone Area, Standard Area and Virtual-Link Example Topology as You Can See, in this Topology, There Area Standard (Area 0) and Three Standard (Normal) Areas (Area 1, Area 2, Area3).

FIRSTLY Let’s Configure the IP Addresses on All Routers:

Afterface Interface Configurations, Let’s Configure the Ospf on All Routers. HERE, OSPF Process Number Will BE 1 and the Routerx’s Router Id Will BE X.x.x.x. Beside this, All the Connected Areas Will Be Configured.

AFTER DOINT THIS Configuration Will See All The Network on Topology Table Except Area 3. Area 3 is not Directly Connected to the Backbone Area, Area 0. SO in the Routing Table of the Routers There Will Be no Route to this Area 3.

Interface IP Configurations

For OUR OSPF Virtual Link Configuration Example, Firstly, We Need to Configure the IP Addressing on the Physical Interface and On Loopback Interfaces. We Will Configure these IP Addresses as Expressed ABOVE On Each Router.

Router a (config)# Interface Loopback0

Router a (config-if)# IP Address 1.one.one.1

Router a (config-ma)# interface fa0/0

Router a (config-if)# IP Address

Router a (config-if)# Exit

Router B (Config)# Interface Loopback0

Router B (Config-Ar)# IP Address

Router b (config-if)# interface fa0/1

Router B (Config-Ar)# IP Address

Router b (config-maF)# Interface FA0/0

Router B (Config-Ar)# IP Address

Router b (config-ma)# exit

Router C (Config)# Interface Loopback0

Router C (Config-Ar)# IP Address

Router C (Config-Arf)# Interface FA0/1

Router C (Config-Ar)# IP Address

Router C (Config-Arf)# Interface FA0/0

Router C (Config-Arf)# IP Address

Router C (Config-Arf)# Exit

Router D (Config)# Interface Loopback0

Router D (Config-Ar)# IP Address 4.four.four.4

Router D (Config-Ar)# Interface FA0/1

Router D (Config-Ar)# IP Address

Router D (Config-Ar)# Exit

Creating OSPF Processes and Adding Networks to OSPF

Afterface IP Configuration, We Will Configure Ospf Process and Add Ospf Networks Under this Interface. Here, We Will Uspf Process Number 1. Router a is in area 0, router b isa area border router (ABR) and it is on Both Ara 0 and Area 1. AGain, Router C IS Anrea Border Router (ABR) and In Two Different Areas, In Area 1 Andrea 2. And Lastly, Router D Will Be in Area 2 Only. The InterFaces Will BE Added to these Ospf Process with Th, AREAS WITH NETWORK Addresses and Required WildCard Mask.

Router a (config)# Router OSPF 1

Router a (config-Router)# Network Area 0

Router B (Config)# Router OSPF 1

Router B (Config-Router)# Network Area 0

Router B (Config-Router)# Network Area 1

Router C (Config)# Router OSPF 1

Router C (Config-Router)# Network Area 1

Router C (Config-Router)# Network Area 2

Router D (Config)# Router OSPF 1

Router D (Config-Router)# Network Area 2

Line and reverse mask

In the Cisco equipment, sometimes you have to use a reverse mask, that is, not familiar to us (Subnet Mask. direct mask), and (WildCard Mask. Reverse Mask). The reverse mask is used in the tolerance sheets and when describing networks in the OSPF protocol. Direct mask is used in all other cases. The difference between masks also lies in the fact that the direct mask operates with nets, and the opposite. by hosts. With the help of a reverse mask, you can, for example, allocate hosts with a specific address in all subnets and allow them to access the Internet. So, as the most bowl in local networks use addresses like 192.168.one.0 with mask, then the most common WildCard Mask (template mask or reverse mask. or inverse mask). Mask

Template mask (Wildcard Mask). a mask indicating the number of hosts of the network. Is an addition to the subnet mask. It is calculated according to the formula for each of the octets mask of the subnet as 255-mask_ subnet. For example, for the network 192.168.one.0 and mask subnet Template mask will look like The template mask is used in setting up some routing protocols, and is also a convenient parameter of restrictions in the access lists.

WildCard Mask calculation

There is a connection. Between the reverse and direct mask: in total, these masks for each category should be 255. Let our network /28. Calculates WildCard Mask: Prefix /28 This is or 1111111.1111111.1111111.11110000. For WildCard Mask, we need only zeros, that is, we transfer 11110000 to a decimal number and believe: 128/64/32/16/8/4/2/1 this will be 8421 = 15, t.e. Our WildCard Mask will be 0.0.0.fifteen.

Dan Direct Mask Calculate and prove that the reverse is equal to

Command line

If you press the button (playback), then we will see the entire cycle of passing the package over the network (the process will be repeated 4 times). rice. 2.9.

TTL is the life time of the sent package (determines the maximum number of routers that the package can pass when it is promoted),

Time. time spent on sending a request and receiving a response,

Practical work 2-2. Setting up network parameters PC in its graphic integration

Add to our network another PC. PC4. An example of a changed network of five PC and 2 hubs (TASK-2-2 file.PKT) is attached.

Open the properties of the PC4 device by clicking on its image. To configure the computer, we will use the IPCONFIG command from the command line (rice. 2.ten).

Настройка OSPF на оборудовании Cisco

As an option, the IP address and network mask can be entered in the graphical integration of the device (rice. 2.eleven).

On each computer, we will check the parameters assigned by the IPConfig command (rice. 2.12).