Question 145 of 250 from exam 400-201: Cisco CCIE Service Provider Written Exam

Question 145 of 250 from exam 400-201: Cisco CCIE Service Provider Written Exam

Question

In a MPLS TE implementation, which three IS-IS TLVs are used for MPLS-TE? (Choose three.)

Answers

Explanations

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A. B. C. D. E. F.

BEF.

https://www.cisco.com/c/en/us/support/docs/ip/integrated-intermediate-system-to-intermediate-system-is-is/5739-tlvs-5739.html

Sure! In a MPLS Traffic Engineering (TE) implementation with IS-IS as the Interior Gateway Protocol (IGP), several IS-IS TLVs (Type-Length-Value) are used to carry MPLS-TE specific information. TLVs are a way of encoding data in IS-IS protocol and they allow the exchange of information between IS-IS routers.

The three IS-IS TLVs used for MPLS-TE are:

  1. TLV 22: Extended IS Reachability: This TLV is used to advertise the MPLS-TE attributes of an IS-IS router to its neighboring routers. It carries information such as the router's TE capabilities, maximum bandwidth, and the link color that identifies the class of service for traffic engineering.

  2. TLV 134: Traffic Engineering Router ID: This TLV is used to advertise the router ID that is used for MPLS-TE purposes. This is not necessarily the same as the IS-IS router ID, as the TE router ID can be manually configured to be different.

  3. TLV 135: Extended IP Reachability: This TLV is used to advertise the MPLS-TE attributes of IP prefixes. It carries information such as the available bandwidth, maximum reservable bandwidth, and the link color for each IP prefix.

The other options mentioned in the question are:

A. TLV 10: Authentication: This TLV is used for authentication purposes and is not specific to MPLS-TE.

C. TLV 128: IP Integrated Reachability: This TLV is used to advertise IP reachability information and is not specific to MPLS-TE.

D. TLV 132: IP Interface Address: This TLV is used to advertise IP interface addresses and is not specific to MPLS-TE.

Therefore, the correct options are B, E, and F.