Since your IP is subnetted, we need the complete IP address of both systems. We also need to know more detail about how these systems are connected, and that includes any broadband Internet connections, if you have a router, etc.
Originally posted by Huh: its 2 laptop under Win ME
192.016.000.001
255.255.254.000
***.***.***.002
**************
with a crossover cable,no internet acces
That's why you can't see each other. You can't use 254 in the subnet mask, it isn't valid. Try changing the 254 in the subnet mask to 255 and then see what happens.
Although he's using a Class B subnet mask on Class C addresses, I don't see why it wouldn't work on a simple network between two computers. I mean, there's no gateway to confuse or anything. (If I get REALLY bored at home, I might try it just to see what happens.)
But technically, the subnet mask for a Class C address should be 255.255.255.xxx. When something's not working, let's start by making sure everything's configured properly. Then see if you can ping one computer from the other. If you get a ping reply, TCP/IP's working, and then we can worry about getting file sharing working.
Originally posted by SkyDog: Although he's using a Class B subnet mask on Class C addresses, I don't see why it wouldn't work on a simple network between two computers. I mean, there's no gateway to confuse or anything. (If I get REALLY bored at home, I might try it just to see what happens.)
But technically, the subnet mask for a Class C address should be 255.255.255.xxx. When something's not working, let's start by making sure everything's configured properly. Then see if you can ping one computer from the other. If you get a ping reply, TCP/IP's working, and then we can worry about getting file sharing working.
It won't work because 254 is not a valid address when subnetting. Valid numbers are:
128
192
224
240
248
252
You also have to keep in mind that subnetting does create different domains. For example, lets say that he/she did actually use a valid number like 252. His/Her availabe addresses per domain are only 2. You can figure it out by taking 256-252=4 and then you have to subtract 2 again because you have the domain address and the other is the broadcast address. In this case valid numbers for hosts would be 2 & 3 because 1 would be the domain and 4 would be the broadcast. Now in the previous case if you use 254 you would get 256-254=2-2=0...so no valid host addresses.
Originally posted by Un4given: It won't work because 254 is not a valid address when subnetting. Valid numbers are:...
Oh yeah. (Duh!) I know that valid decimal subnet numbers have to correlate to the the binary places. That *and* the "-2 rule" slipped my mind.
Last time I dealt with subnetted networks was in a Cisco class in '96. It's amazing how much of that knowledge comes back in a hurry when someone points out you're wrong!
Originally posted by SkyDog: Oh yeah. (Duh!) I know that valid decimal subnet numbers have to correlate to the the binary places. That *and* the "-2 rule" slipped my mind.
Last time I dealt with subnetted networks was in a Cisco class in '96. It's amazing how much of that knowledge comes back in a hurry when someone points out you're wrong!
Thanks for the reminder!
I know what you mean. I'm taking Cisco classes myself...CCNP stuff.
Well, from what I recall, that subnet mask isnt completely invalid. Isnt that supernetting? I remember it being typically used just on the routers to keep the routing tables smaller. However, couldnt it be used otherwise as well (even if Microsoft OSs dont know what to do with it)?
[This message has been edited by Nabu_the_Wise (edited September 27, 2001).]
Originally posted by SkyDog: Oh yeah. (Duh!) I know that valid decimal subnet numbers have to correlate to the the binary places. That *and* the "-2 rule" slipped my mind.
Last time I dealt with subnetted networks was in a Cisco class in '96. It's amazing how much of that knowledge comes back in a hurry when someone points out you're wrong!
Thanks for the reminder!
i know it...i took the class in 98-99. it does come back real quick...thats why im gonna start postin' in the networking section here...gotta keep up on this stuff so i dont forget everything i learned...
Originally posted by Nabu_the_Wise: Well, from what I recall, that subnet mask isnt completely invalid. Isnt that supernetting? I remember it being typically used just on the routers to keep the routing tables smaller. However, couldnt it be used otherwise as well (even if Microsoft OSs dont know what to do with it)?
[This message has been edited by Nabu_the_Wise (edited September 27, 2001).]
No, what he is doing isn't supernetting, if anything it was subnetting. Doing this allows you to have more than one domain when all you have is one, but it reduces the number of hosts possibilities. However, this is only important if the network will be exposed to the outside world. A LAN that isn't exposed can use any addressing scheme they want. However, since he only has a two computers (via x-over cable) connection, I don't know why he even opted for anything but a standard subnet mask and address.
If he were using a supernet the proper net mask would be 10.168.0.0/23 thats 23 bit subnet mask. That would be the first usable class b subnet. However he should use a straight class c 192.168.0.0/24 this will give him the full class c without any problems.
By the way that /23 is 255.255.254.0. This is a good subnet. His problem is that he is not using a valid address. 192.0.0.0 is a class c. If you use a 10.168.0.0/23 it will work.
Sub/supernetting can be tricky.
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VP6 with dual GIG and loving it
issues on crossover
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