vlink-peer

Function

The vlink-peer command creates and configures a virtual link.

The undo vlink-peer command deletes the virtual link or restores the default setting.

By default, no virtual link is configured.

Format

vlink-peer router-id [ hello hello-interval | retransmit retransmit-interval | trans-delay trans-delay-interval | dead dead-interval | smart-discover | [ simple [ plain SPlainText | [ cipher ] SCipherText ] | { hmac-sha256 | md5 | hmac-md5 } [ key-id { plain MPlainText | [ cipher ] MCipherText } ] | authentication-null | keychain keychain-name ] ] ^*

undo vlink-peer router-id

undo vlink-peer router-id { hello | retransmit | trans-delay | dead | simple | hmac-sha256 | md5 | hmac-md5 | authentication-null | keychain | smart-discover }

Parameters

Parameter	Description	Value
router-id	Specifies the router ID of a virtual link neighbor.	The value is in dotted decimal notation.
hello hello-interval	Specifies the interval at which Hello packets are sent on an interface. This value must be equal to hello-interval value of the Device that sets up the virtual link through the interface.	The value is an integer ranging from 1 to 65535 seconds. The default value is 10 seconds.
retransmit retransmit-interval	Specifies an interval at which LSAs are retransmitted on an interface.	The value is an integer ranging from 1 to 3600, in seconds. The default value is 5 seconds.
trans-delay trans-delay-interval	Specifies the delay in sendingLSAs on an interface.	The value is an integer ranging from 1 to 3600, in seconds. The default value is 1 second.
dead dead-interval	Specifies the dead interval. This value must be equal to dead-interval of the Device that sets up a virtual link through the interface. In addition, the value must be at least 4 times of hello-interval.	The value is an integer ranging from 1 to 235926000, in seconds. The default value is 40 seconds.
smart-discover	Sends unsolicited Hello packets.	-
simple	Indicates the simple authentication mode. The new password is at least eight characters long and contains at least two of the following types: upper-case letters, lower-case letters, digits, and special characters. For security purposes, you are advised to configure a password in ciphertext mode. To further improve device security, periodically change the password.	-
plain	Indicates the plain authentication. You can only type in the simpletext, and it is displayed as a simpletext in the configuration file. When configuring an authentication password, select the ciphertext mode because the password is saved as a simpletext in the configuration file if you select the simpletext mode, which has a high risk. In addition, to ensure device security, change the password periodically.	-
SPlainText	Specifies a simpletext.	The value is a string of characters. In simple mode, the value is a string of 1 to 8 characters. In md5, hmac-md5 or hmac-sha256 mode, the value is a string of 1 to 255 characters. Except the question mark (?) and space. However, when quotation marks (") are used around the password, spaces are allowed in the password.
cipher	Indicates the cipher authentication. You can type in a simpletext or ciphertext, but it is displayed as the ciphertext in the configuration file.	-
SCipherText	Specifies a ciphertext.	The value is a string of characters. For simple authentication, a simpletext is 1 to 8 characters, and a ciphertext password is 24 to 128 characters. For MD5, HMAC-MD5, or HMAC-SHA256 authentication, a simpletext is 1 to 255 characters, and a ciphertext password is 20 to 432characters. Except the question mark (?) and space. However, when quotation marks (") are used around the password, spaces are allowed in the password.
hmac-sha256	Indicates the HMAC-SHA256 authentication mode. By default, the hmac-sha256 authentication mode is cipher.	-
md5	Indicates the MD5 authentication mode. By default, the md5 authentication mode is cipher. For the sake of security, using the HMAC-SHA256 algorithm rather than the MD5 algorithm is recommended.	-
hmac-md5	Indicates the HMAC-MD5 authentication mode. By default, the hmac-md5 authentication mode is cipher. For the sake of security, using the HMAC-SHA256 algorithm rather than the HMAC-MD5 algorithm is recommended.	-
key-id	Specifies a key ID for ciphertext authentication. The key ID must be consistent with that of the peer.	The value is an integer ranging from 1 to 255.
MPlainText	Specifies a simpletext.	The value is a string of characters. In simple mode, the value is a string of 1 to 8 characters. In md5, hmac-md5 or hmac-sha256 mode, the value is a string of 1 to 255 characters. Except the question mark (?) and space. However, when quotation marks (") are used around the password, spaces are allowed in the password.
MCipherText	Specifies a ciphertext.	The value is a string of characters. For simple authentication, a simpletext is 1 to 8 characters, and a ciphertext password is 24 to 128 characters. For MD5, HMAC-MD5, or HMAC-SHA256 authentication, a simpletext is 1 to 255 characters, and a ciphertext password is 20 to 432characters. Except the question mark (?) and space. However, when quotation marks (") are used around the password, spaces are allowed in the password.
authentication-null	Indicates the null authentication mode.	-
keychain	Indicates the keychain authentication. Before configuring this parameter, run the keychain command to create a keychain. Then, run the key-id, key-string, and algorithm commands to configure a key ID, a password, and an authentication algorithm for this keychain. Otherwise, the OSPF authentication fails. If the dependent keychain is deleted, the neighbor relationship may be interrupted. Therefore, exercise caution when deleting the keychain.	-
keychain-name	Specifies a keychain name.	The value is a string of 1 to 47 case-insensitive characters, question marks (?) and spaces not supported. However, the string can contain spaces if it is enclosed in double quotation marks (" ").

Views

OSPF area view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
ospf	write

Usage Guidelines

Usage Scenario

After OSPF is divided into different areas, OSPF routes between non-backbone areas are updated by route exchange with the backbone area. Therefore, OSPF requires that all non-backbone areas keep connected to the backbone area and devices within the backbone area also keep connected. In real-world scenarios, however, these requirements cannot be met due to various limitations. Configuring OSPF virtual links can solve the problem.

Configuration Impact

Establish virtual links between the non-backbone areas and the backbone area, and between devices within the backbone area to ensure connectivity in an OSPF network.

Follow-up Procedure

Different vendors may use different MTUs as default settings. To ensure consistency, run the undo ospf mtu-enable command to set the default MTU to 0 when DD packets are sent on an OSPF interface.

If the MTU of DD packets is configured, the neighbor relationship will be reestablished.

Precautions

The default value is recommended when a virtual link is created. You can modify the value as required. Suggestions for configuring parameters are as follows:

The smaller the hello value, the faster the device detects network topology changes, and the more network resources are consumed.
If the retransmit value is set too small, LSAs may be retransmitted. Setting the parameter to a large value is recommended on a low-speed network.
The authentication modes of a virtual link and the backbone area must be the same.
The virtual link function does not apply to DCN processes.

Example

# Configure a virtual link with the peer Router ID 1.1.1.1.

<HUAWEI> system-view
[~HUAWEI] ospf 100
[*HUAWEI-ospf-100] area 2
[*HUAWEI-ospf-100-area-0.0.0.2] vlink-peer 1.1.1.1