IP question

to put simply if you are using an ip address with default subnet
mask the no of bits turned on in the subnet mask represent network portion
& no of bits turned on repreents host portion
if you use 192.168.0.x then 192.168.0 is network portion & X is the
host portion if you are using subnet mask greater than defualt subnet mask the it is
said to be a subnetted one.

the difference for
1)192.168.0.0/24
2)172.10.0.0/24
3)10.20.0.0/24

is that first ip adddress is using the default subnet mask where as the other two are
using subnetted mask.

hope this will help u in getting answer for u r firdt quetion,

as far your second question is concerned i have not got u want u want say exactly can u
elaborate it

thanks

Apit, do I understand your second question correctly to mean that currently your network has only one VLAN using a Class B network?

If so, I would hope that there is some sort of use of routers, since it seems your network contains about 5000 users. That's a big network if not! Broadcasts would become a problem in a network that big that isn't subnetted down into smaller "pieces".

Apit,

Let’s ignore some misuse of terminology . Let’s just say that over all you are getting some good information on an IP addressing problem. jwj’s answer of No to your first question was right on . Taurn did a good job of explaining exactly why .

It appears your real question is how to address a network with 10 VLANs allowing for 500 users on each VLAN. If you are not restricted by any other constraints as you might find in a Cisco Academy scenario you should make this easy for yourself and use the private class A address of 10.0.0.0 and subnet it with a class B subnet mask. This will allow for future growth and make your addressing scheme simple and easy to scale. You will have more than enough subnets and host addresses for now and the future.

For example:

VLAN 10 – IP address 10.10.0.0 255.255.0.0 giving you 65,534 host addresses
VLAN 20 – IP address 10.20.0.0 255.255.0.0 etc.

You would have a total possible of 256 VLANs but there are some you should not use. It is suggested you do not use VLAN 1 as this it the default VLAN and every hacker knows this. This means you should change your management VLAN to something other than VLAN 1. You may want to use a scheme that uses every 5th or 10th VLAN but not on numbers divisible by 5 or 10. For example:

VLAN 13 – IP address 10.13.0.0 255.255.0.0
VLAN 23 – IP address 10.23.0.0 255.255.0.0

You may also want to make your management VLAN not fit the pattern of you other VLAN addresses. For example VLAN 17 – IP address 10.17.0.0/16

You should note that all of the addresses start with the network number 10 and the second octet is used for the VLAN number and the last two octets are used for host addresses. Making your VLAN numbers and your IP address correspond helps make addressing easy to follow and makes troubleshooting you network easier.

You might choose to do something more obscure if security is a real concern using any class B private address (172.16.0.0 – 172.31.0.0) and using a subnet mask in the range of 255.255.192.0 and 255.255.252.0 (/18 - /22). This would allow for at least 1000 hosts per subnet and with the use of multiple class B addresses at least 60 subnetwork numbers assuming you are willing to use the zero and all 1s subnets. I would suggest that before using the all 1s subnet that you download and study the “Zero and all 1s subnet” pdf from cisco.com.

Good luck and have fun Subnetting. :lol:

Apit, do I understand your second question correctly to mean that currently your network has only one VLAN using a Class B network?

If so, I would hope that there is some sort of use of routers, since it seems your network contains about 5000 users. That's a big network if not! Broadcasts would become a problem in a network that big that isn't subnetted down into smaller "pieces".

yup...currently we have 1 vlan
broadcasting is the main issue..is it?
so i come out with this design
please advise


|''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''|
|vlan...........|...........ip range .........................|... subnet........|
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''|
|blok1.........|172.25.0.1 - 172.25.1.254.........|255.255.254.0|
|blok2.........|172.25.2.1 - 172.25.3.254.........|255.255.254.0|
|blok3.........|172.25.4.1 - 172.25.5.254.........|255.255.254.0|
|blok4.........|172.25.6.1 - 172.25.7.254.........|255.255.254.0|
|blok5.........|172.25.8.1 - 172.25.9.254.........|255.255.254.0|
|blok6.........|172.25.10.1 - 172.25.11.254.....|255.255.254.0|
|blok7.........|172.25.12.1 - 172.25.13.254.....|255.255.254.0|
|blok8.........|172.25.14.1 - 172.25.15.254.....|255.255.254.0|
|blok9.........|172.25.16.1 - 172.25.17.254.....|255.255.254.0|
|blok10.......|172.25.18.1 - 172.25.19.254.....|255.255.254.0|
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

Apit,

You should note that all of the addresses start with the network number 10 and the second octet is used for the VLAN number and the last two octets are used for host addresses. Making your VLAN numbers and your IP address correspond helps make addressing easy to follow and makes troubleshooting you network easier.

that mean:

10.25.100.1
10= network number
25=vlan
100.1 = host

I would suggest that before using the all 1s subnet that you download and study the “Zero and all 1s subnet” pdf from cisco.com.

Good luck and have fun Subnetting. :lol:

nice tutorial..thanks a lot mew

Your new IP addressing scheme looks fine Apit. I hope your implimentation goes smoothly for you.