Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
Help configuring eth0
- Thread starter farley99
- Start date
Hmmm,
That netmask is invalid. They may have meant 255.255.255.240 but that would mean the IP address 92.116.60.15 is invalid too as for that mask, it would be a network address and not a host address. Why? Simplifying it, a range of hosts determined by a subnet can also be referenced by a network address (which identifies the subnet alone, and the broadcast which can be used to identify all hosts at one time).
To use the standard 255.255.255.0 as an example - this determines 254 possible machines on a subnet. So for a network of 192.168.1.0, the hosts are 192.168.1.1 to 192.168.1.254 and the broadcast address is 192.168.1.255
With 255.255.255.224 - this determines 30 hosts in the subnet. As one IP address is 192.116.60.15, it can be calculated that the network address is:
192.116.60.0
The hosts on the subnet are:
192.116.60.1 to 192.116.60.30
and the broadcast is:
192.116.60.31
And as an example, the 'next' subnet would be:
192.116.60.32 (net)
192.116.60.33 to 62 (hosts)
192.168.60.63 (broadcast)
This is a good online calculator:
Maybe they meant 255.255.255.224
That netmask is invalid. They may have meant 255.255.255.240 but that would mean the IP address 92.116.60.15 is invalid too as for that mask, it would be a network address and not a host address. Why? Simplifying it, a range of hosts determined by a subnet can also be referenced by a network address (which identifies the subnet alone, and the broadcast which can be used to identify all hosts at one time).
To use the standard 255.255.255.0 as an example - this determines 254 possible machines on a subnet. So for a network of 192.168.1.0, the hosts are 192.168.1.1 to 192.168.1.254 and the broadcast address is 192.168.1.255
With 255.255.255.224 - this determines 30 hosts in the subnet. As one IP address is 192.116.60.15, it can be calculated that the network address is:
192.116.60.0
The hosts on the subnet are:
192.116.60.1 to 192.116.60.30
and the broadcast is:
192.116.60.31
And as an example, the 'next' subnet would be:
192.116.60.32 (net)
192.116.60.33 to 62 (hosts)
192.168.60.63 (broadcast)
This is a good online calculator:
Maybe they meant 255.255.255.224
- Thread starter
- #3
- Status
Similar threads
- Locked
- Question