The networks `172.1.4.0/25`, `172.1.4.128/25`, `172.1.5.0/24`, `172.1.6.0/24`, and `172.1.7.0/24` can be covered by the summary `172.1.4.0/22`.

### Why this is right The two `/25` networks together fill `172.1.4.0/24`. Adding the next three contiguous `/24` networks gives the range from `172.1.4.0` through `172.1.7.255`, which is exactly the four `/24` blocks covered by the aligned `/22` summary. ### The concept A `/22` covers four consecutive `/24` networks when it starts at an appropriate boundary. The listed network addresses fill that block without a gap: the two halves of the fourth-octet range for third octet 4, followed by the full third-octet ranges 5, 6, and 7. This is a useful example of combining smaller routes into a larger summary. ### Terms - **IP**: Internet Protocol. The addressing system used to identify and route packets. ### Remember Combine adjacent subnet blocks, then verify that the proposed summary covers exactly the intended range.