DIGIT-ARC read-only archive · snapshot: July 23, 2026

Lan different classes question

20 posts · originally from https://geek.digit.in/community/threads/lan-different-classes-question.25773/

__Virus__
__Virus__ Original post #1
Mar 21, 2006 at 5:30 PM
Yoo Ppl,

I have a small question here. First lemme tell you about me and my bros ips and all.

Me:

Ip: 192.168.11.141
Subnet: 255.255.255.0
Gateway: 192.168.11.1
Primary DNS: 192.168.11.1
Secondary DNS: 202.56.x50.x


Bro:

Ip: 192.168.12.149
Subnet: 255.255.255.0
Gateway: 192.168.12.1
Primary DNS: 192.168.12.1
Secondary DNS: 202.56.x50.x


Everything is same except the different classes in which our ISP divided us. Since my ISP doesnt use a router we cant access each others pcs ( or is there any way ?) My brother had some issue with his pc and came to my place. I just plugged in my lan cable (which is suppose to take all trafic from 192.168.11.blabla) to his pc and the net was working like charm :shock: and he was connected to his network i,e 12.blabla ( and was able to access internet) thinking that if i change my ip to 12.sumthn I will be able to connect to ( internet and) his pc ( when he is back at his home) and vice versa, I changed the settings and accordingly and got one free ip on lan i,e 12.150, when I hooked up my lan cable to my pc with the ip config same as my bros ( with different ip off cos :D ) , I wasnt even on network *geocities.com/dalordvirus/thinking.gif I connected his pc back and it was again smooth... Y is this discrimination with my pc *geocities.com/dalordvirus/sad.gif *geocities.com/dalordvirus/thinking.gif Any help will be greatly appreciated *geocities.com/dalordvirus/grin.gif
A
ashnik #2
Mar 22, 2006 at 2:18 AM
i think the mac address problem. the ISP must have registered ur lancard's mac address.
__Virus__
Mar 22, 2006 at 5:24 AM
Nopes...they dont do that way and am cent percent sure about that :)
S
susk21 #4
Mar 22, 2006 at 7:35 AM
Which is your ISP?
Is the network too large or it is small?
Everybody on your network use static IP?
T
Mar 22, 2006 at 11:54 AM
do u use cyberoam client for login ?
if u do it'll probably tell u "you are not allowed to login from this machine"

it is infact true that isps log ur MAC addresses .. and the above is proof of that ..

tell us how u connect to the net .. or do u just plug it in and its on ?

BTW ... ur not on DIFFERENT CLASSES of IP's
you're only on different SUBNETS

now if all the pc's are connected ... try chanign ur subnet masks to 255.255.0.0 and see if now u can connect to ur bros pc .

you cannot just change ur ip address
your isp RESERVES this private ip address for your machine
u just cant pick another one .
so try keepin ur ip and connect ur bros cable .. just like u did with ur bros comp at ur place .
S
susk21 #6
Mar 22, 2006 at 6:48 PM
theraven,i have a question!
My lan assigns me a dynamic IP address.
The range is:169.254.84.xxx
and another:192.168.0.xxx
It keeps on changing between Class B and Class C within a day or two.
So a friend of mine who is connected to my LAN from the same hub,at times get differnt network.So we cant share
our data due to such problem.So we have entered an IP manually on our PCs. What problem does my service provider get? Is it illegal?
T
Mar 22, 2006 at 10:07 PM
169.254.x.x is the ip address provided when NO DHCP SERVER IS FOUND
its an isp FAULT ...
i forgot what that range is called. .. will ahve to dig up the books/google. .
digens on leave to ... otherwise he'd have contributed ..
anyways ... like i said. .
mediator
Mar 22, 2006 at 11:02 PM
@virus....There's no discrimination with ur PC ! I aint understand ur problem clearly.......but first lets make it clear!
U cant access ur bro's PC until u 2 are on the same IP range i.e u on xx.xx.xx.y1 and ur bro on xx.xx.xx.y2.

Now u said ur ip is 192.168.11.141 and ur bro's 192.168.12.149. These are the IP's most commonly assiged by ur router. Now,

1) If u and ur bro have ur pc's under the same router and lan ip's are as 192.168.11.xx......then u can access and share filez easily...I mean lan cud be setup!
In this case the both pc's will show the same network IP!

2)considering ur network IP(one assigned by isp and not the router) is something like 57.18.34.12 and ur bro's as 57.18.57.1 then u ofcors cant access each other's PC!
In this case if u want to access each others pc, then then u both oughta know each other's network ip and then u shud set port forwarding on ur router......i.e if u wanna telnet u shud forward 23 port in the router settings!

3)Now again, if both pc's are having the same network IP and one pc is in a different subnet than others, then lan cannot be setup and to share filez settings have to be made which i dunno!

So just by changing ur ip u cant access ur bro's pc! for setting lan u shud be on the same local network!

I hope that helps u!
iinfi
iinfi #9
Mar 23, 2006 at 2:26 AM
@theraven:
even though the IP addresses and gateway are different, how do u say that he is on different subnets.
i dont mean to say u r wrong.

its only that i am never able to understand this concept and i think i will never ever be able to understand networking in my life. at least if i attend atleast 1 mumbai meet u guys wud teach me what it is, but i always have to miss it coz of some reason. :(
__Virus__
__Virus__ #10
Mar 23, 2006 at 4:21 PM
Thanks all for replying.

@Raven

No, I dont user any clients to login and I dont get any message watsoever called "You are not allowed to login from this

machine"

I just plug my LAN cable in and its on. ( I never unplug it though :D )

My bad, you are correct we are on different subnets :D

""now if all the pc's are connected ... try chanign ur subnet masks to 255.255.0.0 and see if now u can connect to ur bros

pc""

I will give this one try and surely let u know

""you cannot just change ur ip address your isp RESERVES this private ip address for your machine u just cant pick another

one. so try keepin ur ip and connect ur bros cable .. just like u did with ur bros comp at ur place""

No, I can change the ip n number of times I want. I just scan the network and if any Ip is free I use it ( only and only if

have some work and if am testing sumthn with two pcs at my place or sum1 else starts using my IP :) )

@ Mediator

"""Now u said ur ip is 192.168.11.141 and ur bro's 192.168.12.149. These are the IP's most commonly assiged by ur router.

Now"""

No, My ISP doesnt use even a single router between our different classes what all he uses are those lame hubs. I literally

asked him to install a router between subnets of me and my bro's so that it will be very easier for us, but that lazy kid

wont listen.



""1) If u and ur bro have ur pc's under the same router and lan ip's are as 192.168.11.xx......then u can access and share

filez easily...I mean lan cud be setup!
In this case the both pc's will show the same network IP!""

Yes had he provided us with a router it wud have been very simple for us to access but.......... he is known as hub guy :D


"")considering ur network IP(one assigned by isp and not the router) is something like 57.18.34.12 and ur bro's as 57.18.57.1

then u ofcors cant access each other's PC!
In this case if u want to access each others pc, then then u both oughta know each other's network ip and then u shud set

port forwarding on ur router......i.e if u wanna telnet u shud forward 23 port in the router settings!""

Exactly ips are not assigned by router.

""So just by changing ur ip u cant access ur bro's pc! for setting lan u shud be on the same local network! ""



Ok Mediator, I want to clarify two of your last quotes sentences above.

So, until and unless am not on his network I cant access his pc. Now we indeed are on same network, just this stupid subnets

he changed.

Ill put this in simplest of ways. If my hub was to take all the ips like 192.168.11.blabla and not any ips from different subnet like 192.168.12.blabla.... then y did my bros pc worked when I just hoooked up my lan cable to his pc which has IP 192.168.12.149 ?????? and When I hook the same plug to my pc, which has IP 192.168.11.141, it was working. So regardless of the Ip address we were online. And when i xeroxed his ip configuation to my pc, i wasnt able to do so. The only two things that were left in my mind were as Raven and someone said "" You mac addy was logged and hence you are unable to do so"" I really understand this concept..but had MAC addy was logged... how did my bro's pc was online from my place with my lan cable (precise word)

Now the only thing am left with is..changing the subnet to 255.255.0.0 and give this a try, once I post this and restart my PC for the same...

Any clarification will be very highly appreciated .... Thanks all again.. holaaa :D


PS: Plz ignore typos if any or all.. I just woke up :D
T
theraven #11
Mar 23, 2006 at 4:33 PM
iinfi .. its a simple thing .. get this
if ur subnet is 255.255.255.0
that means the last octect is "dont care" condition
meanin it could be anything from 1 -254 and it would be on the same subnet
if any of the first 3 octets is different it means they are on different subnets ;)


@virus . im sorry man .. i dun understand ur isp's implementation ONE BIT ..
i think its extremely loose and irresponsible and insecure .
wait for digen .. he should be back next week .. ill speak to him n see if we can think of a solution
__Virus__
__Virus__ #12
Mar 23, 2006 at 4:38 PM
Raven no need at allllllll. I thank my isp for been lame ass kid and insecure :D so here it is

**Signs $10 Million check and presents it to Raven, at the same time bows down *geocities.com/dalordvirus/bow.gif*geocities.com/dalordvirus/bow.gif*geocities.com/dalordvirus/bow.gif and thanks for that trick which made me access my bros pc..subnet changed to 255.255.0.0

and what does it have to do with changing of subnet from 255.255.255.0 to 255.255.0.0 *geocities.com/dalordvirus/thinking.gif
T
theraven #13
Mar 23, 2006 at 7:38 PM
glad to be of help :)
mediator
mediator #14
Mar 23, 2006 at 11:38 PM
well that was a new lesson!
but entering the static ip of 192.bla.bla.bla shud have generated the default subnet isnt it?
__Virus__
__Virus__ #15
Mar 24, 2006 at 3:31 AM
the default subnet which it generates is 255.255.255.0 thanks again raven
iinfi
iinfi #16
Mar 24, 2006 at 7:44 AM
hmmm.... thanks for the info raven bhai

Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . : 220.224.7.8
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 220.224.7.8

mine is only a dialup conn. hence posting these details. whats the subnet here mean??? :?:
ilugd
ilugd #17
Mar 24, 2006 at 12:55 PM
Raven, just wondering. in the above post by iinfi the subnet mask is given as 255.255.255.255. Does that mean he won't be able to connect to anyone?
T
theraven #18
Mar 24, 2006 at 2:17 PM
yeah apparently ..
iinfi ... did u make a mistake entering ur subnet ??
the last should be 0 !!
otherwise u wont be on a network

@mediator ... YES the default subnet is 255.255.255.0
MEANIN ONLY THE LAST OCTET CAN BE CHANGED
look at his and his bros ip ..
the 2nd octet is different too . puttin then on different subnets

hope its clear now
mediator
mediator #19
Mar 24, 2006 at 6:00 PM
Ok yea crystal clear now.....@raven...thanx bro!
__Virus__
__Virus__ #20
Mar 24, 2006 at 6:18 PM
got couple of questions related to telnet and remote desktop will ask tomo gota hurry nowww