Q&A
| Q1: | How large is the subnet ID field on a Class B network with the mask 255.255.0.0? |
| A1: | Zero bits (no subnet ID field). The mask 255.255.0.0 is the default condition for a Class B network. All 16 mask bits are used for the network ID, and no bits are available for subnetting. |
| Q2: | A network admin calculates that he'll need 21 mask bits for his network. What subnet mask should he use? |
| A2: | 21 mask bits: 11111111111111111111100000000000 is equivalent to two full octets plus an additional 5 bits. Each full octet is expressed in the mask as 255. The five bits in the third octet are equivalent to 128+64+32+16+8 = 248. The mask is 255.255.248.0. |
| Q3: | You have a Class C network address. You also have employees at 10 locations, and each location has no ... |
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