Hello Just,
you need to look at the third byte write it in binary
1 = 0000 0|001
3 = 0000 0|011
5 = 0000 0|101
you need to look at the common bits from the LEFT, that are the first 5 bits before '|' this means the inclusive aggregate (that includes also other subnets) is:
moving three bits to the left from /24 boundary : 24-3 = 21 this is the prefix length
192.2.0.0/21
if you look at summary routes that do not include other subnets the answer is negative: there is no way to aggregate these subnets without including other ones because they are not contigous
the fact that all of them have the last bit set to 1 in common is not useful
Hope to help
Giuseppe
