I hv configured redhat linux ver.6.2 using the pcquest June CD.
I want to enable demand dialing to the internet on the server.
I hv configured "diald" for this purpose but im not able to connect.
I am also attaching the "diald.conf" and the "connect" file.
The "msg" file contains snapshot of the /var/log/messages file.
thnks in advance
Lison
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Thursday, June 22, 2000 4:13 PM
To: [EMAIL PROTECTED]
Subject: Re: [ILUG-BOM] Netmask
Mail from ILUG-BOM list (Non-Digest Mode)
Sometime Today, Rajen Parekh assembled some asciibets to say:
> BTW, what is Netmask? And what do the nos. 255.0.0.0 [or something like
> that] means.
You have IP addresses: 202.54.1.18, 192.168.0.1, 127.0.0.1, 89.1.1.200
etc
It is actually a 32 bit integer split into 4 8 bit integers so that it
becomes easier for humans to handle.
These IP addresses come in different classes depending on how big a
network they can service.
If you have a really large network (a few million computers) then you'd
want what is known as a class A network address.
Class A networks have the most significant bit as zero. So basically, the
first number in your IP address dotted format will range from 0 to 127.
0 of course is reserved, so you can't use that.
1.0.0.0 to 127.0.0.0 Are your class A networks - each of which can
address 16777214 machines (note, 2^24 - 2 because 0 and 255 are not
allowed).
127.0.0.1 is your loopback address, so is also eliminated.
Now, you have class B addresses, that have msb 1 and next bit 0. So this
creates a range from 128.0.0.0 to 191.0.0.0. This isn't your network
address though. Your network address is 128.x.0.0 to 191.x.0.0 where x is
any integer from 0 to 255.
Similarly, Class C addresses start with 110 (in binary) and range from:
192.0.0.0 to 224.0.0.0 (not entirely sure about this), with network
addresses 192.x.y.0 to 224.x.y.0
There's also Class D, and many more subclasses that aren't important right
now.
Now the big question is, how do you figure out what part of an IP address
is the network address, and which part is the actual machine number.
That's where the netmask comes in.
For a class A network, the mask is 255.0.0.0. If you perform a bitwise
ANDing of this with an Class A IP address (eg: 10.0.0.18) you will get the
network address: 10.0.0.0
If you NAND it with the network address, you get the number of hosts that
can be addressed by that network: 0.255.255.255 = 16777216.
Now, if you have a really small network (<100 machines) you want a really
restrictive netmask: 255.255.255.127 maybe
and with a network address like 240.120.15.0, you would be able to address
240.120.15.0 NAND 255.255.255.127 = 128 machines.
Your network address and subnet mask together tell machines which network
they belong to, what broadcast address they should use etc. It also tells
them which other machines belong to their network - which makes it easy
for you to have to different logical networks on the same cable.
Hope this explains it.
Philip
--
What this country needs is a good five cent microcomputer.
_______________________________________________
Linuxers mailing list
[EMAIL PROTECTED]
http://ilug-bom.org.in/mailman/listinfo/linuxers
diald.conf
msg
connect
