для Cisco Cisco IOS Software Release 12.0(13)S7

Perform the following tasks to configure the MPLS—LDP MD5 Global Configuration feature:

 (required)

 (optional)

You might require password protection for a certain set of neighbors for security reasons (for example, 
to prevent LDP sessions being established with unauthorized peers, or to block spoofed TCP messages). 
To enforce this security, you can configure a password requirement for LDP sessions with those 
neighbors that must have MD5 protection (TCP session uses a password). 

If you configure a password requirement for a neighbor and you did not configure a password for the 
neighbor, LDP tears down the LDP sessions with the neighbor. LDP also tears down the LDP sessions 
with the neighbor if you configured a password requirement and a password and the password is not used 
in the LDP sessions.

If a password is required for a neighbor and the LDP sessions with the neighbor are established to use a 
password, any configuration that removes the password for the neighbor causes the LDP sessions to be 
torn down. 

To avoid unnecessary LDP session flapping, you should perform the task as described in this section and 
use caution when you change LDP passwords.

Perform the following task to identify LDP neighbors for LDP MD5 password protection.

Before you start to configure passwords for LDP sessions, you must identify neighbors or groups of 
peers for which you want to provide MD5 protection. For example: 

You might have several customers that all use the same core routers. To ensure security you might 
want to provide each customer with a different password. 

You could have defined several departmental VRFs in your network. You could provide password 
protection for each VRF. 

Certain groups of peers might require password protection for security reasons. Password protection 
prevents unwanted LDP sessions.

Before you start to configure passwords for LDP sessions, you must identify neighbors or groups of 
peers for which you want to provide LDP MD5 password protection. This task uses the network in 

 to show how you might identify LDP neighbors for LDP MD5 protection. 

After you identify LDP neighbors or a group of peers for LDP MD5 protection, you must decide if 
password protection is mandatory and what password commands to use for each peer.