Review Question no 13

[arvind]

HI,
I the solution, you have mentioned that both hosts have different masks and hence the mask needs to be changed. First in the question the masks are the same and I dont know why you say they are different, i.e. they are 255.255.255.240 in both the hosts, sorry if am missing something.
Next you have said that making both masks /24 will solve the problem, and here i again dont see how that will solve the problem because both addresses have the first 24 bits in common and hence wont there be a problem in routing,

namely 192.168.1 is the common part in the ip address of both hosts which is 24 bits. so how will a /24 mask solve the problem?

Thanks for answers,
Arvind

[tsunamoro]

Because the two hosts are in two different subnets due to the 240 in the last subnet mask octect.

240 means that the increment value is 16 and starting from 0, the subnets are 0, 16, 32, 48, 64, 80, 96, etc.
The right host is in the 192 subnet, when the left one is in the 16 subnet.
For the two host to talk eachother, without changing the ip addresses, you have to find a bigger subnet that includes both subnets. The first one you find is /24.

HTH.

[arvind]

Hey thanks a lot, its clear now.

Arvind

[tsunamoro]

You're welcome.
However, you're right when you say that the masks are the same.
The expalanation isn't very clear. In my opinion , I'd change it, getting rid of "the hosts have different masks..." and putting a simple "Second, the hosts belong to two different subnets."

[lammle]

I meant to say in the explanation that the hosts "have" the same mask, which puts them in different subnets...or something like that....Either way, technically, the answers are correct. You need a crossover and you need to fix the IP scheme so both routers are on the same subnet.
Cheers!
Todd Lammle