Static routing, an alternative to dynamic routing, is the process in which the system network administrator manually configured network routers with all the information necessary for successful packet forwarding. The administrator creates a routing table in each device, placing entries for each network, which may be the destination. Static data paths for network routes are immutable.
Definition
The static method is a network routing method managed by a network administrator, which consists in manually configuring and selecting a network route. Used in scenarios where network settings and environment must remain constant.
Routing is one of the most important data transfer procedures. This ensures that data moves from one network to another with optimal speed and minimum delay, and that its integrity is maintained in this process.
Broadly, routing is done in two different ways:
- Dynamic - periodically updates its routing table with paths and their cost / metric, making optimal decisions based on changes in network operating conditions.
- Static - it is considered the simplest form of this process, fulfills routing rules with pre-configured data transfer paths in the table, which can be changed manually only by administrators.
Static routes are commonly used in situations where the choice is limited or there is only one default path available. In addition, the static technique can be used if there are only a few devices for setting the route, and in the future there will be no need to change it.
Varieties of routing
A device can use three paths to explore routes:
Static routing is a method by which an administrator manually adds information transfer paths to a spreadsheet / database.
Default routing is a technique where all routers are configured to send all packets on the same path. This is a very useful method for small networks or for networks with a single entry and exit point. It is commonly used in addition to static and dynamic methods.
A dynamic technique is a way in which protocols and algorithms are used to automatically distribute routing information. This is the most common and most complicated method.
Protocol classification
Routing protocols are classified as internal gateway protocols (IGP) or external gateway protocols (EGP). IGPs are used to exchange process information on internetworks that fall under a single administrative domain (also called autonomous systems). EGPs are used to exchange information between various autonomous systems. Common examples of IGP are Routing Protocol (RIP), Enhanced Internal Gateway Protocol (EIGRP), and Open Shortest Path First (OSPF).
The routing protocol uses software and algorithms to determine the optimal transmission of network data and communication paths between network nodes. Also known as routing policy. They greatly facilitate the interaction of routers, as well as the general topology of the network.
Most Internet Protocol (IP) networks use the following routing protocols:
Routing Protocol (RIP) and Internal Gateway Routing Protocol (IGRP): Provides a process for internal gateways through routing or remote vector protocols. RIP is used to determine the shortest path from source to destination. This allows you to transfer data at high speed in the shortest possible time.
Open Shortest Path First (OSPF): Provides a process for internal gateways through channel state routing protocols.
- Border Gateway Protocol (BGP) v4: Provides a public routing protocol through external communication with the gateway.
How to Configure Cisco Static Routing
To configure a static route, the device must be in global configuration mode.
Code for the command line: ip route prefix mask {address | interface} [distance]. Explain the main components of the code:
network - the target network;
mask - subnet mask for this network;
address - IP address of the next hop router;
interface - equipment interface of outgoing traffic;
distance is the administrative distance of the route.
The administrative distance is used to apply a kind of prioritization on static routes, so that different paths to a given destination will follow a specific activation pattern. The administrative distance is an integer from 0 to 255, where 0 indicates the path of first priority, and 255 means that traffic cannot pass through this route. By default, the administrative distance of directly connected interfaces is 0, and for static routes, 1.
Static Routing Example:
ip route 10.0.0.0 255.0.0.0 131.108.3.4 110, where 10.0.0.0 is the target network, 255.0.0.0 is the subnet mask, and 131.108.3.4 is the next leap for the router used, 110 is the administrative distance.
Example of creating a static route
As an example of when a static route is required, consider the following case:
Your primary access to the Internet is through a cable modem for your Internet service provider.
You have an ISDN router in your home network to connect to the company you work for. The address of this device on your local network is 192.168.1.100.
The network address of your company is 134.177.0.0.
When configuring cisco static routing, two implicit static routes are created.
The default data path was created with your provider as a gateway, and a second static route is created on the local network for all addresses 192.168.1.x. In this configuration, when trying to access a device on a 134.177.0.0 network, the router redirects the request to the Internet service provider.
In this case, it is necessary to determine the static route, indicating to the device that 134.177.0.0 should be accessible through the ISDN router at 192.168.1.100.
Static and dynamic routers
To work effectively on a gateway network, routers must have information about other identifiers or be configured using the default path. In large networks, routing tables must be maintained so that traffic always moves along the optimal paths. From how spreadsheets are supported, the distinction is made between static and dynamic routing.
Static routing
A device with manually configured routing tables is known to users as static. The network administrator, who owns the network topology, manually creates and updates the table of information paths, programming all the routes. Static routers may work well for small gateways, but do not scale for large or dynamically changing gateways because of their manual administration.
A good example of a static device is a multi-network computer running Windows 2000 (a computer with multiple network interfaces). Creating static routing in Windows 2000 is as simple as installing multiple network interface cards, configuring TCP / IP, and enabling IP routing.
Dynamic routing
A device with dynamically configured tables is known as dynamic. Dynamic routing consists of tables that are created and maintained automatically through constant communication between devices. This message is facilitated by a routing protocol, a series of periodic or on-demand messages containing information exchanged by routers. Dynamic devices, with the exception of their initial configuration, require little ongoing maintenance and can scale to larger internetworks.
Dynamic routing is failover. Dynamic data paths received from other devices have a limited lifespan.
The ability to scale and recover from network errors makes this a better choice for medium to large networks.
A dynamic technique is a network method that provides optimal data routing. Unlike static, dynamic allows routers to choose paths in accordance with changes in the logical network in real time. In a dynamic process, a protocol running on a device is responsible for creating, maintaining, and updating a data spreadsheet. In static routing, all these tasks are performed manually by the system administrator.
The dynamic technique uses many different algorithms and protocols. The most popular are Routing Protocol (RIP) and Open Shortest Path First (OSPF).
Routing costs are a critical factor for all organizations. The least expensive technology of this process is provided by a dynamic technique that automates table changes and provides the best paths for stable data transfer.
The dynamic routing protocol operations can be explained as follows:
Routers change routing information to discover data about remote networks. Whenever a device finds a change in topology, the routing protocol makes a topology change on other devices.
Dynamic routing can be easily configured in large networks and is more intuitive when choosing the best way to transmit information, detect changes, and detect remote networks. However, since routers exchange updates, they consume more bandwidth than in the static technique. Processors and the equipment operating system may also experience additional workloads as a result of more complex protocol work. Dynamic routing is less secure than static routing.
Comparative analysis
Static Routing cisco is not a routing protocol. This is simply the process of manually entering routes into the device data spreadsheet via a configuration file that loads when the device starts. Alternatively, these data paths can be entered by the network administrator, who manually configures them. Since these manually configured routes do not change after they are configured, they are called static.
A static technique is the simplest form of routing, but it is a painstaking manual process. Use this method when you have very few devices to configure (less than 5), and you are sure that the transmission paths of information will probably never change.
The static routing of the cisco packet tracer also does not handle random failures in external networks, because any route that is configured manually must be updated or reconfigured manually in order to repair or restore lost connections.
Dynamic routing protocols are supported by software applications running on the receiving / transmitting device (router).
A device using a dynamic technique recognizes routes for all networks that are directly connected to it. Then the router examines the data of other devices that run the same protocol (RIP, RIP2, EIGRP, OSPF, IS-IS, BGP). Each router then sorts the route list and selects one or more optimal paths for each network destination.
Then dynamic routing protocols distribute the received data to other devices working with one protocol, thereby expanding the information about which networks exist and can be reached. This gives dynamic protocols the ability to adapt to changes in the logical topology of the network or failures of the static routing router.
Pros and cons
Static routing has the following advantages:
No additional processing and additional resources, as in the case of dynamic routing protocols.
No additional bandwidth requirements caused by excessive packet transfers for the routing table update process.
Additional security is determined by manually entering or rejecting the transmission of information to certain networks.
Configuring static routing is more secure.
There are no overhead costs for using static routes. With dynamic network bandwidth is used to connect available networks between routers. When using static routes, since the network administrator encodes the data, devices do not need to transmit routing information.
Static routing is easier to configure for a small network. Suppose you have only two devices and you need to configure a message between them. To do this, you need to configure only two route operators - one on each router. With a dynamic protocol such as RIP, for example, you would have to enter two network operators on each device.
Static routes do not require any significant router resources. A dynamic routing protocol, such as OSPF, can require significant resources to calculate the shortest path over a network with a large number of connected devices.
The disadvantages include the following:
Network administrators should be familiar with the entire network topology in order to properly configure data transmission paths.
Topology changes require manual configuration of cisco packet tracer static routing for all devices, which is very laborious.
Static routes do not scale as the network grows. This is due to the fact that they are all manually configured by the administrator.
With a dynamic technique, there is no manual intervention, and traffic is routed automatically whenever a network outage occurs. It is also quite scalable and easily manageable.
What is the difference between static and dynamic routing?
Static IP routing is when you statically configure a device to send traffic to specific destinations in pre-configured destinations. The dynamic way is when you use a routing protocol such as OSPF, ISIS, and EIGRP or BGP to figure out what type of traffic should go through. In the real world, there are very few situations where only one of two methods is used. A typical network will use the dynamic OSPF protocol to determine the optimal routes within the enterprise, BGP to determine the best exit points for the rest of the Internet and static routing to send specific traffic along the selected routes.
IP addressing and routing: how does it work?
Routers, in order to be able to transfer packets to their final destination, must maintain a routing table that stores all the necessary information containing a combination of networks and output interfaces.
Each time the device receives the packet, it checks the IP address of the recipient and tries to find, looking in its data spreadsheet, the possible route of information to this IP address. Routers do not send broadcasts in search of remote networks: if the network is not listed in the table, the device simply drops the packets.
When to use default routing
The default routing is used only in stub networks. Stubs are networks that have only one output interface, and everything passing through these networks must cross a single exit point.
Instead of a large number of static routes pointing to remote networks through a single output interface, one default route is configured that matches all possible routes.
Use of administrative distances
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