All The Useful MPLS Interview Questions & Answers for CCIE

What Functions Does MPLS Perform?
When this question is asked, you have to explain a few things to the interviewer. First, you have to explain adding, changing, and removing the label as MPLS performs them.

There are proper terms for these functions. For example, PUSH means adding the title, SWAP means changing the brand, and POP means removing the tag.

Differentiate Between P and PE Router?
When you are asked about these routers, you have to mention that customer network routes could be accessed on a P router, whereas the PE router lacks this feature.

Moreover, MP-iBGP is necessary for PE routers and not needed for P routers.

What Exactly Is TTL Propagation?
This question can be efficiently answered by stating the abbreviation of TTL first. TTL stands for Time-to-live.

The process in which TTL value is copied from IP header and pasted to MPLS header is known as TTL propagation.

The TTL value is the time when data or a packet exists on a computer before getting discarded.

How Can VPNV4 and IPV4 Address Families Be Distinguished?
Vpnv4 address family is used for transferring VRF communication which is more significant than Ipv4 packets. Its size is 96 bits, while the size of Ipv4 boxes is 32 bits. The Ipv4 address family transmits these ordinary Ipv4 packets.

Is There Any Method Through Which MPLS Labels Can Be Sifted?
When the interviewer asks this question, your answer should be yes. Then you have to describe how this method works and that we can filter the MPLS labels by using ACLs.

ACL stands for Access Control List. These are the rules which can be practiced for the filtration of network traffic. MPLS labels can also be filtered by using LDP filtering.

Is a Route-Reflector a Must-Have for the Proper Usage of MPLS?
The quick answer to such a question is yes. Because MPLS can be used without a route reflector, this can be made possible by using BGP. A full mesh BGP can be helpful to run MPLS without a route reflector.

What is SYSVOL?
SYSVOL is a separate folder that is used to keep the copy of the domain's public files which belong to the server. All domain controllers have this folder.

Therefore, SYSVOL is considered an essential constituent of the active directory.

Can Two Customers Have the Same Rd Assigned to Them?
No, because RD is different for every router. The primary purpose of RD is to keep all the prefixes unique, which is why RD cannot be the same for more than a single customer.