BSCI question, any ideas?

The correct answer is E. In a classless system, the router uses the bit mask to determine the network and host portions; the subnet mask is passed along with each routing update. So A and C are wrong! In a classful system, the router determines the class of an address (A, B or C) and the mask is assumed to be default (255.0.0.0, 255.255.0.0 or 255.255.255.0) or the one configured on the receiving interface. So B & D are wrong!

Doan

many thanks for the reply Doan,

This may sound like a very elementary question but is "bit mask" just short for "subnet mask"?

Regards Paul

Im not Doan but I'll put this out there:

Basically a bit mask is a subnet mask written in binary. Instead of

When your deal> many thanks for the reply Doan,

Thanks Nick.... I'm not too bad with the old binary but I must admit I tend to think more in decimal and just rememering that 252's go up in 4's, 248's go up in 8's etc. any tips on 'thinking in binary' greatly appreciated!

Regards Paul

I had a wonderfully written easy to understand explanation that would have burned subnet bitmasks indelibly into your head... Then Thunderbird crashed....

Real quick this time (kids need to hit the rack):

A teacher in a CCNA class showed me how to write the following chart. It may be well known but its the only place I have seen it.

Octet:

A. Subnet bits (dont know why I place this) B. Bit Placement C. Bit "worth" (cant think of the terminology) D. Number of hosts per subnet E. Subnet Mask F. Number of Subnets. This is using all 0's and all 1's. Minus 2 for each one if you are avoiding it. I don't recall what Cisco recommends.

You d> Thanks Nick.... I'm not too bad with the old binary but I must admit I tend

thanks Nick, I think I'll jot that down when I get into the exams in future, undoubtably useful. Cheers