221.177.152.0/26 should match 221.177.152.0 - 221.177.152.63. Can you try logging the client IP to verify what you're getting for [IP::remote_addr]?
Here's a v11 rule you can use to confirm this:
when RULE_INIT {
for {set i 0}{$i <=63}{incr i}{
log local0. "\[IP::addr 221.177.152.$i equals 221.177.152.0/26\]: [IP::addr 221.177.152.$i equals 221.177.152.0/26]"
}
}
[IP::addr 221.177.152.0 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.1 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.2 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.3 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.4 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.5 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.6 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.7 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.8 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.9 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.10 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.11 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.12 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.13 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.14 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.15 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.16 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.17 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.18 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.19 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.20 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.21 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.22 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.23 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.24 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.25 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.26 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.27 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.28 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.29 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.30 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.31 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.32 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.33 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.34 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.35 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.36 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.37 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.38 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.39 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.40 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.41 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.42 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.43 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.44 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.45 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.46 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.47 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.48 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.49 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.50 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.51 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.52 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.53 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.54 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.55 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.56 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.57 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.58 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.59 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.60 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.61 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.62 equals 221.177.152.0/26]: 1
[IP::addr 221.177.152.63 equals 221.177.152.0/26]: 1
Aaron