Designing IS-IS for IPv6 Integration
Question
An engineer is creating a design to enable IPv6 to run on an existing IPv4 IS-IS network.
The IPv4 and IPv6 topologies will match exactly, and the engineer plans to use the same IS-IS router levels for each protocol per interface.
Which IS-IS design is required?
Answers
Explanations
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A. B. C. D.B.
In order to enable IPv6 to run on an existing IPv4 IS-IS network, an engineer has to consider several design options. One key requirement is to ensure that the IPv4 and IPv6 topologies are an exact match, meaning that the same IS-IS router levels should be used for each protocol per interface. Based on these requirements, the engineer should choose the appropriate IS-IS design.
Option A: Multi-topology without enabling transition feature Multi-topology is a design approach where multiple logical topologies are used within a single physical topology. This option would allow the engineer to use different topologies for IPv4 and IPv6 traffic, but it does not enable the transition feature. Therefore, this option is not suitable for running IPv6 on an existing IPv4 IS-IS network without disrupting the IPv4 traffic.
Option B: Multi-topology with transition feature enabled This option allows the engineer to use different topologies for IPv4 and IPv6 traffic, and also enables the transition feature, which allows IPv4 and IPv6 networks to coexist and interoperate. This option is suitable for running IPv6 on an existing IPv4 IS-IS network because it provides a smooth transition from IPv4 to IPv6.
Option C: Single-topology without enabling transition feature Single-topology is a design approach where a single logical topology is used for both IPv4 and IPv6 traffic. This option does not enable the transition feature, which means that IPv6 traffic will not be able to coexist with IPv4 traffic on the same network. Therefore, this option is not suitable for running IPv6 on an existing IPv4 IS-IS network.
Option D: Single-topology with transition feature enabled This option enables the transition feature, which allows IPv4 and IPv6 networks to coexist and interoperate on the same physical topology. This option is suitable for running IPv6 on an existing IPv4 IS-IS network because it provides a smooth transition from IPv4 to IPv6, while still using a single logical topology.
In conclusion, Option B (Multi-topology with transition feature enabled) or Option D (Single-topology with transition feature enabled) would be the appropriate IS-IS design for enabling IPv6 to run on an existing IPv4 IS-IS network while maintaining exact topology matches.
