HPE7-A04 · Question #31
One of your customers has the following: 2-Tier L2 Design - 8325 32x100G Core Switches - 8360 48x10G RJ-45 Access Switches - 100G 5M DAC connections between Core and Access Core Switches = VSX Pairs…
The correct answer is B. 14. Option B (14) is correct because each core switch has 29 remaining 100G ports after VSX (32 total minus 3 for ISL/keepalive), and each access switch VSX pair consumes 2 ports per core switch - one uplink from each access switch in the pair. Dividing 29 available ports by 2…
Question
One of your customers has the following:
2-Tier L2 Design
- 8325 32x100G Core Switches
- 8360 48x10G RJ-45 Access Switches
- 100G 5M DAC connections between Core and Access
Core Switches = VSX Pairs of 8325 32-port 100G switches (F-B airflow). Access Switches = VSX Pairs of 8360-48xBaseT switches (F-B airflow). Each Core Switch pair uses the following for VSX:
- 2 x 100G QSFP28 1M DACs for ISL
- 1 x 100G QSFP28 1M DAC for Keepalive
Each Access Switch pair uses the following for VSX:
- 2 x 100G QSFP28 1M DACs for ISL
- 1 x 10G RJ45 cable for Keepalive
Each Core switch has 29 remaining available 100G QSFP28 interfaces for access switch connectivity. This solution uses 1x100G QSFP28 5M DAC from each access switch to each core switch. This solution can scale up to a maximum of 14 racks using the same subscription rates.
Options
- A12
- B14
- C16
- D18
How the community answered
(18 responses)- A11% (2)
- B61% (11)
- C22% (4)
- D6% (1)
Explanation
Option B (14) is correct because each core switch has 29 remaining 100G ports after VSX (32 total minus 3 for ISL/keepalive), and each access switch VSX pair consumes 2 ports per core switch - one uplink from each access switch in the pair. Dividing 29 available ports by 2 gives 14.5, which floors to 14 access switch pairs (racks) before a core switch runs out of ports.
Option A (12) is wrong because it leaves 5 unused ports on each core switch - the design can physically support more racks than this.
Option C (16) is wrong because 16 pairs × 2 ports = 32 ports needed, which exceeds the 29 available (you'd be 3 ports short).
Option D (18) is wrong for the same reason - 18 × 2 = 36 ports required, far beyond the 29-port limit.
Memory tip: Use the formula (Total ports − VSX ports) ÷ uplinks per access pair = max racks. Here: (32 − 3) ÷ 2 = 14.5 → 14. Always floor the result since you can't connect half a rack.
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