On a class B network several of the third octets are already in use. They have been allocated in an ad hoc fashion so I do not have contiguous entries lining up on bit boundaries.
Are the following ACL entries valid to block these network ranges
access-list 20 deny ip x.x.9.0 0.0.2.255 to block 9,10 and 11 ( 8 is already allocated )
access-list 20 deny x.x.33.0 0.0.30.255 to block from 33 to 63 ( again 32 has been allocated )
The first access list will only block 9 and 11 subnets. You need to add one statement in access-list 20 for 10' subnet. If you use wildcard mask as 0.0.3.255 four subnets i.e., 8 to 11 will be blocked, which is not desired as 8 is already allocated.
The second access list will block all odd subnets starting from 33 to 63. To block 33 to 63 with 32 permitted, I would suggest one statement permitting 32' subnet and then using 0.0.31.255 wildcard mask. The packet for 32' subnet will be permitted first and access-list will not be checked after a match is made. All other packets for other subnets will be dropped. This way you will achieve in just two statements instead of 14 or so statements.
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