Configuring LDP MD5 Authentication

Context

MD5 authentication can be configured for a TCP connection over which an LDP session is established, improving security. Note that the peers of an LDP session can be configured with different encryption modes, but must be configured with a single password.

The MD5 algorithm is easy to configure and generates a single password which can be changed only manually. MD5 authentication applies to the network requiring short-period encryption.

Keychain authentication and MD5 authentication cannot be both configured on a single LDP peer.

LDP authentication configurations are prioritized in descending order: for a single peer, for a specified peer group, for all peers. Keychain and MD5 configurations of the same priority are mutually exclusive. Keychain or MD5 authentication can be configured simultaneously for a specified LDP peer, for this LDP peer in a specified peer group, and for all LDP peers. The configuration with a higher priority takes effect. For example, if MD5 authentication is configured for Peer1 and then keychain authentication is configured for all LDP peers, MD5 authentication takes effect on Peer1. Keychain authentication takes effect on other peers.

Configuring LDP MD5 authentication may cause LDP session reestablishment, deletion of the LSP associated with the deleted LDP session, and MPLS service interruption.

MD5 encryption algorithm cannot ensure security. Keychain authentication is recommended.

Procedure

Run system-view
The system view is displayed.
Run mpls ldp
The MPLS-LDP view is displayed.
Configure LDP MD5 authentication.

If plain is selected, the password is saved in the configuration file in plain text. In this case, users at a lower level can easily obtain the password by viewing the configuration file. This brings security risks. Therefore, it is recommended that you select cipher to save the password in cipher text.
- Configure LDP MD5 authentication for a single LDP peer.
  
  Run md5-password { plain | cipher } peer-lsr-id password
  
  MD5 authentication is configured and a password is set.
  
  By default, LDP MD5 authentication is not performed between LDP peers.
- Configure LDP MD5 authentication for LDP peers in a specified LDP peer group.
  1. Run md5-password { plain | cipher } peer-group ip-prefix-name password
    
    MD5 authentication is enabled and a password is set for LDP peers in a specified LDP peer group.
    
    An IP prefix list can be specified using ip-prefix-name to define the range of IP addresses in a group. Before using an IP prefix list, ensure that the IP prefix list must have been created.
  2. (Optional) Run authentication exclude peer peer-id
    
    The device is disabled from authenticating a specified LDP peer.
    
    By default, after LDP MD5 authentication is enabled for a specified LDP peer group, MD5 authentication takes effect on all LDP peers in the group. To disable the device from authenticating a specified LDP peer in the group, perform this step.
- Configure LDP MD5 authentication for all LDP peers.
  1. Run md5-password { plain | cipher } all password
    
    MD5 authentication is enabled and a password is set for all LDP peers.
  2. (Optional) Run authentication exclude peer peer-id
    
    The device is disabled from authenticating a specified LDP peer.
    
    By default, after LDP MD5 authentication is enabled for all LDP peers, MD5 authentication takes effect on all LDP peers. To disable the device from authenticating a specified LDP peer, perform this step.