Gateway album -- Dual-line dual-network

We all know that China's network service provision has been monopolized by China Netcom and China Telecom, but there are still some problems with network sites, here we will look at how to implement dual-line dual-channel network through routing policies.

As we all know, China's domestic network access service providers are basically monopolized by China Netcom and China Telecom, and there are some problems with online and site access, that is, if your network belongs to the China Netcom line, the access to China Telecom's resources will be slow, and if your network is provided by China Telecom, similarly, access to China Netcom resources will be slow. This is why many enterprise users have begun to apply for dual-line solutions to solve this problem. But do we know how to rationally allocate network access outlets and links as a network administrator? By rationally allocating the destination IP address, we can make better use of network resources, so that the data accessing the telecom network can be sent to the telecom link, and the data accessing the Netcom can be smoothly sent to the Netcom link. Today, we invite you to learn how to use routing policies to automatically allocate routing information for dual-line dual-channel networks, making data packet forwarding more intelligent.

I. Advantages of routing policies

We have introduced how to solve this two-line dual-channel network problem from the routing information of the Local Computer. However, this method is only applicable to a single computer, the setting of one machine is definitely not realistic. In this case, we can use routing policies to manage the enterprise's network route egress and configure reasonable routing policies on the egress router, so that network packets can be forwarded to different lines according to different requirements.

In general, the commands of the routing policy only need to be set on the vro connecting the external egress of the enterprise network. The vro actually connects to the dual-line dual-channel, that is, an interface connects to the network connected to China Netcom, and an interface connects to the network connected to China Telecom.

Ii. Routing Policy commands

The routing policy enables the router to select the next hop route information according to certain rules, so that the router can automatically select the basic information of the received network packet, determine the route table in which the data should be forwarded. Through the routing policy, we can specify multiple next hop forwarding route addresses for a vro. Next, let's take a look at a route policy command, and then learn its meaning based on the instructions following it.

(1) set the basic information of the routing policy:

Route-map src80 permit 10

// Create a policy route with the name src80 and serial number 10. The rule is allowed.

Matches ip address 151

// Set match to meet the condition. This means that the set operation is performed only when the ip address meets the requirements in access control list 151. Otherwise, the set operation is skipped directly.

Set ip next-hop 10.91.31.254

// Modify the next hop route information of the data to 10.91.31.254 if the preceding conditions are met.

Access-list 150 deny tcp any 10.80.0.0 0.7.255.255 eq www

Access-list 150 permit tcp 10.80.0.0 0.7.255.255 any eq www

// Set the matching information in access control list 150 (1)

(2) Enable and take effect of the configured routing policy on an interface:

Int FastEthernet3/2

// Access the Gigabit Ethernet Interface

Ip policy route-map src80

// Apply the routing policy src80.

No ip policy route-map src80

// Cancel the application of the src80 routing policy.

Of course, the actual commands of each routing policy will be different, but the basic commands such as match and set are similar. We can modify them as needed during actual use.