Sigma globals do not work.
The site is using a class C address, with a class B subnet mask.
The following is an explanation of why the Sigma globals in this configuration do not work.
An IP Address is divided in to two sections: Net ID and Host ID. The Host ID is further divided in to two Sections: Subnet ID and Host ID.
- The Subnet Mask determines the Subnet ID bits and Host ID bits.
- Number of Mask bits should be greater than that of Net ID bits.
For example a Sigma address is 192.168.0.1 with 24 bit mask 255.255.255.0
- Number of subnet ID bits is zero and Host ID bits is 8;
- Broadcast address is 192.168.0.255
With 28 bit mask 255.255.255.240
- Number of subnet ID bits is 4 and Host ID bits is 4;
- Broadcast address is 192.168.0.15
For Class C:
- Address range is: 192.0.0.0 to 184.108.40.206 inclusive
- Net ID is 24 bits; Host id is 8 bits; Minimum Mask size is 24 bits;
For Class B:
- Address range is: 220.127.116.11 to 18.104.22.168 inclusive
- Net ID is 16 bits; Host id is 16 bits; Minimum Mask size is 16 bits;
In the site set up, 192.168.xxx.xxx is a Class C address; this can have at least 24 bit mask; 16 bit mask is invalid;
Using an Address 190.168.xxx.xxx works correctly because it is a Class B address and supports 16 bit masking; hence works properly.
For globals to work correctly, either use >= 24 bit mask for the subnet 192.168.xxx.xxx, or move to class B subnet 190.168.xxx.xxx.