300-510 · Question #56
Refer to the exhibit. A service provider technician is working on a multicast issue for a customer. While checking the multicast table, the technician notices that no flags are present for the…
The correct answer is C. Only the default SSM range is permitted. The address range 232.0.0.0/8 is the IANA-designated default SSM (Source-Specific Multicast) range. The range 239.0.0.0/8 is the administratively scoped range, typically used for ASM (Any-Source Multicast). If the device is configured to permit only the default SSM range…
Question
Refer to the exhibit. A service provider technician is working on a multicast issue for a customer. While checking the multicast table, the technician notices that no flags are present for the (1.1.1.1, 239.1.1.1) entry, yet flags are present for the (1.1.1.1, 232.1.1.1) entry. Which factor might explain this issue?
Exhibit
Options
- AOnly the administratively scoped range is permitted
- BOnly ASM is permitted
- COnly the default SSM range is permitted
- DOnly GLOP is permitted
How the community answered
(28 responses)- A4% (1)
- B14% (4)
- C79% (22)
- D4% (1)
Explanation
The address range 232.0.0.0/8 is the IANA-designated default SSM (Source-Specific Multicast) range. The range 239.0.0.0/8 is the administratively scoped range, typically used for ASM (Any-Source Multicast). If the device is configured to permit only the default SSM range (232.0.0.0/8), then multicast group 232.1.1.1 will have active PIM-SSM state and will show flags, while 239.1.1.1 falls outside the SSM range and will not be processed the same way - resulting in no flags. Option A is wrong because 239.x.x.x is administratively scoped (not the only permitted range here). Option B is wrong because ASM is not what's permitted - SSM is. Option D is wrong because GLOP (233.0.0.0/8) is a separate range not involved here.
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