HP 5920 Series Command Reference Manual page 104

undo authentication-mode
Default
No authentication is performed for an area.
Views
OSPF area view
Predefined user roles
network-admin
Parameters
hmac-md5: Specifies the HMAC-MD5 authentication mode.
md5: Specifies the MD5 authentication mode.
simple: Specifies the simple authentication mode.
key-id: Specifies a key by its ID in the range of 0 to 255.
cipher: Sets a ciphertext key.
plain: Sets a plaintext key.
password: Specifies a password. In simple authentication mode, a plaintext password is a case-sensitive
string of 1 to 8 characters, and a ciphertext password is a case-sensitive string of 33 to 41 characters. In
MD5/HMAC-MD5 authentication mode, a plaintext password is a case-sensitive string of 1 to 16
characters, and a ciphertext password is a case-sensitive string of 33 to 53 characters.
Usage guidelines
Routers that reside in the same area must have the same authentication mode and password.
For security purposes, all keys, including keys configured in plain text, are saved in cipher text.
You can specify either MD5/HMAC-MD5 authentication or simple authentication for an OSPF area. For
MD5/HMAC-MD5 authentication, you can configure multiple keys by executing this command multiple
times, and each command must have a unique key ID and key string.
To modify the key of an OSPF area, perform the following key rollover configurations:
1. Configure a new MD5/HMAC-MD5 authentication key for the area on the local device. If the new
key is not configured on neighbor devices, MD5/HMAC-MD5 authentication key rollover is
triggered. During key rollover, OSPF sends multiple packets that contain both the new and old
MD5/HMAC-MD5 authentication keys to ensure that all neighbor devices can pass the
authentication.
2. Configure the new MD5/HMAC-MD5 authentication key on all neighbor devices. When the local
device receives packets with the new key from all neighbor devices, it exits MD5 key rollover.
3. Delete the old MD5/HMAC-MD5 authentication key from the local device and all its neighbors.
This operation helps prevent attacks from devices that use the old key for communication and
reduces system resources and bandwidth consumption caused by key rollover.
Examples
# Configure OSPF Area 0 to use the MD5 authentication mode, and set the key ID to 15 and plaintext
authentication password to abc.
<Sysname> system-view
[Sysname] ospf 100
[Sysname-ospf-100] area 0
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