Understanding and difference of RD and RT parameters in VRF in MPLS VPN

Recently, I have been reading mpls vpn, but I have never understood the differences between the two RD and RT parameters in VRF. By searching materials on the Internet for repeated reading and thinking, I finally understood it. The following uses a more understandable metaphor for sharing.

For example, if you receive an invitation letter, you need to go to a high-end office building to attend the meeting. Because of the strict security requirements, any person who enters the meeting must register for permission before entering the meeting. At this time, the security guard is similar to PE. The security guard should first verify your identity to accept your private network ), then, tell you which meeting room you should go to and decide which VRF your private network should be sent ). RD is similar to your ID number. For example, your name is Li Ming, and another name is Li Ming, which represents the same private network route in different VPNs ). Then, how can the security guard register? Just register the name Li Ming and you will not be able to make any difference. Then, the security guard will need to record your name and record your ID number, that is, record the RD of the same private network) it is also recorded after the name. After verification, the security guard will tell you which meeting room to go to based on your invitation letter. At this time, the invitation letter is equivalent to RT. I don't know if this is easier to understand.
For example, RD is equivalent to the user id of the computer, and RT is equivalent to the group id. User id is used to identify the uniqueness of your identity. group id is used to identify the attributes of a group. Only users with the same group id can belong to the same group. In this case, the group can be understood as the same VPN.

Question:

• According to this understanding, can the RD values of VRF be different in the same VPN? Because RD identifies VRF.

• In the same VPN, the RT value of VRF must be the same, because RT is equivalent to a VPN attribute, and different VRF can have the same RT to belong to the same VPN.

 

This article from the "light watching sword" blog, please be sure to keep this source http://tecnology.blog.51cto.com/347573/1288473