Sign in to follow this  
Followers 0
bryan372002

Subnet Mask

26 posts in this topic

I forgot to answer this and I vaguely remember that you came to the same conclusion by trying it but the answer is no. For a subnet mask to be valid, its leftmost bits must be set to one and the rightmost bits in a valid subnet mask must be set to zero. The subnet mask determines the network address for the device from the IP address and the subnet mask. An IP address has two components, the network address and the host address. A subnet mask allows you to identify which part of an IP address is reserved for the network, and which part is available for host use. If you look at the IP address alone you can't tell which part of the address is which. Adding the subnet mask gives you all the information you need to calculate network and host portions of the address with ease. Knowing the subnet mask can allow you to easily calculate whether IP addresses are on the same subnet, or not. Here's something interesting to think about- You've got two different network classes Class A addresses have their first octet in the range 1 to 126 (binary address begins with 0). Class B addresses have their first octet in the range 128 to 191 (binary address begins with 10). <--- two of your addresses are Class B Class C addresses have their first octet in the range 192 to 223 (binary address begins with 110). <--- two of your addresses are Class C I didn't see where you listed the subnet mask for each PLC on your network or your laptop (whether assigned by DHCP or manually). That would be good information to know. Info on subnetting and how it works can be found on the net. Here's a couple of links to sites that I like (some of the info I posted here was paraphrased from these links) LINK LINK LINK LINK

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0