a network problem....

Ame M · July 2007

can we use differnet ip addresses..with with certain subnetmasks so as to see each other....as they are in the same network???
for example

host A : 192.168.0.5 255.255.255.0

host B : 192.168.3.2 255.255.252.0

they have the same network address
but not the same brad cast address....
can they see each other????

tech-airman · July 2007

Ame M wrote:

can we use differnet ip addresses..with with certain subnetmasks so as to see each other....as they are in the same network???
for example

host A : 192.168.0.5 255.255.255.0

host B : 192.168.3.2 255.255.252.0

they have the same network address
but not the same brad cast address....
can they see each other????

Ame M,

Questions:

What is the network for Host A?
What is the network for Host B?

Ame M · July 2007

the problem is
we already have a network 192.168.0.0 255.255.255.0

but we need to make supernetting to extend number of hosts

so we decided to make 192.168.110.0 255.255.254.0

and connected these 2 networkd with a router

the problem is we need to make these 2 networks to see each other without a router
what can we do???

brAun · July 2007

why u have to subnetting? just make them as class c 192.168.0.0 255.255.255.0 den they be able to communicate without router... if different network u need a layer 3 device(router) to route the traffic.

Ame M · July 2007

iam using 192.168.0.0 255.255.255.0
but this gives me only 254 host
and i want to extend this network for another 254 host
with condition that they are on the same network

sprkymrk · July 2007

Add the extra hosts on 192.168.1.0 and then make all your hosts (.0 and .1) use a 255.255.254.0 netmask. You'll have a bigger broadcast domain, but it shouldn't bog down a modern network.

tech-airman · July 2007

Ame M wrote:

the problem is
we already have a network 192.168.0.0 255.255.255.0

but we need to make supernetting to extend number of hosts

so we decided to make 192.168.110.0 255.255.254.0

and connected these 2 networkd with a router

the problem is we need to make these 2 networks to see each other without a router
what can we do???

Ame M,

Does the router that connects the "192.168.0.0" network to the rest of the network support subinterfaces?

datchcha · July 2007

Ame M wrote:

the problem is
we already have a network 192.168.0.0 255.255.255.0

but we need to make supernetting to extend number of hosts

so we decided to make 192.168.110.0 255.255.254.0

and connected these 2 networkd with a router

the problem is we need to make these 2 networks to see each other without a router
what can we do???

You can use a layer 3 switch, Hmmm...think Cisco 3xxx series switch will support devices at the Layer 3 level.

dtlokee · July 2007

Why do the networks need to "see" each other without a router? Are you using a non-routable protocol or a application that requires the 2 hosts to be on the same subnet? If that's the case you may want to look into integrated routing and bridging (IRB) or fallback bridging on the switch.

Ame M · July 2007

i can't change the range 192.168.0.x i need to add new range that sees the above range without using a router

brAun · July 2007

actually in layer 2 (switch), all the switches do is read the mac address. so i don't think u need router to see each other in the same network.

Ame M · July 2007

the hosts being on the same switch doesn't mean that they are on the same network
for hosts to see each other without a router they must be on the same network(i.e have the the network address)

brAun · July 2007

yup, u r right. but u don't need a router even u r suppernetting. just make sure both of your client ip address in the range of the network address. for example : network 192.168.128.0 255.255.254.0 and ur client compt 192.168.128.2 n 192.168.128.3 with subnet mask 255.255.254.0.

in that case, u don't need a router to let the client see each other. all u need is hub or switch or if just 2 computer u can plug them together. its will still work.

datchcha · July 2007

brAun wrote:

yup, u r right. but u don't need a router even u r suppernetting. just make sure both of your client ip address in the range of the network address. for example : network 192.168.128.0 255.255.254.0 and ur client compt 192.168.128.2 n 192.168.128.3 with subnet mask 255.255.254.0.

in that case, u don't need a router to let the client see each other. all u need is hub or switch or if just 2 computer u can plug them together. its will still work.

Did i miss understand, but brAun has two differnt subnets, x.x.0.0, and x.x.3.0, so they will need a router, unless i am totally off on this one. And if i am not misstaken, the 3xxx series switch supports Layer 3.

wait2dominate · July 2007

Ame M wrote:

can we use differnet ip addresses..with with certain subnetmasks so as to see each other....as they are in the same network???
for example

host A : 192.168.0.5 255.255.255.0

host B : 192.168.3.2 255.255.252.0

they have the same network address
but not the same brad cast address....
can they see each other????

As for the adresses you posted,

Host A: (192.168.0.5 255.255.255.0)
Network Address : 192.168.0.0
Host Addresses: 192.168.0.1-192.168.0.254
Broadcast Address: 192.168.0.255
(254 Hosts)

Host B: (192.168.3.2 255.255.252.0)
Network Address: 192.168.0.0
Host Addresses: 192.168.0.1-192.168.3.254
Broadcast Address: 192.168.3.255
(1022 Hosts)

Using VSLM, to supernet, will not work in this instance as you have overlapping IP addresses(in the Host A range that covers the first fourth of the Host B range). All the hosts in one range need to be unique to that range only. (Example would be Host A - 192.168.0.5 - falls into both ranges)

The addresses/masks posted will run into errors on your network. A good rule of thumb for VSLM in this instance is that Every netowrk address has a matching broadcast address. You cannot have a one network address with 2 broadcast addresses.

As you posted later in the thread, you want to expand the network to allow another 254 hosts. To do that, you will need to apply a 255.255.254.0 subnet mask along the entire network that host A is in, so the new network would be

Host A(Network 192.168.0.0 S/M 255.255.254.0)
Network Address: 192.168.0.0
Host Addresses : 192.168.0.1-192.168.1.254
Broadcast Address: 192.168.1.255

This would allow for 510 hosts on the network, being able to see each other without the use of a router.

brAun · July 2007

datchcha, i have only 1 network.

the network is 192.168.128.0 255.255.254.0
the host range would be 192.168.128.x - 192.168.129.x
the broadcast address will be 192.168.128.255

i haven't done this for a while, but pretty sure that's correct. just correct me if i m wrong. thanks

sprkymrk · July 2007

sprkymrk wrote:

Add the extra hosts on 192.168.1.0 and then make all your hosts (.0 and .1) use a 255.255.254.0 netmask. You'll have a bigger broadcast domain, but it shouldn't bog down a modern network.

Like I said way back.... do it like this and it WILL work. Just use contiguous network numbers for the 255.255.254.0 mask to work. So if you are currently using 192.168.0.0, make your new one 192.168.1.0. Use a mask of 255.255.254.0 on all your clients. Not sure what is so confusing about this. You don't need a layer three switch, you don't need a router, you don't need to supernet, you don't need a VLAN. All those things are nicer ways to do it, but you said you can't implement those so just configure the clients as stated above and you'll be fine.

brAun · July 2007

sry the broadcast address should be 192.168.129.255 hehe just notice it after i posted

Ame M · July 2007

let tell you the big picture.....
my network is consisting of 9 routers
they are all connected via a frame relay cloud
each eithernet interface of these routers are connected to a private network(starting from 192.168.0.x to 192.168.9.x)

the network in branch 192.168.0.x is full and i want to extend it.
currently i made 192.168.110.0 255.255.254.0 and iam using the firewall as a router to connect between 192.168.0.x and 192.168.110.0 255.255.254.0

what is the ip range that i can use to see 192.168.0.x instead of 192.168.110.0 255.255.254.0 without using the firewall???

EdTheLad · July 2007

Ame M wrote:

let tell you the big picture.....
my network is consisting of 9 routers
they are all connected via a frame relay cloud
each eithernet interface of these routers are connected to a private network(starting from 192.168.0.x to 192.168.9.x)

the network in branch 192.168.0.x is full and i want to extend it.
currently i made 192.168.110.0 255.255.254.0 and iam using the firewall as a router to connect between 192.168.0.x and 192.168.110.0 255.255.254.0

what is the ip range that i can use to see 192.168.0.x instead of 192.168.110.0 255.255.254.0 without using the firewall???

It's hard to understand exactly what you mean but i'll have a shot. All remote sites are on 192.168.1.x/24 -> 192.168.9.x/24 ,change the addressing of the 192.168.0.x/24 to
192.168.16.x/20 , this means you will need to replace the /24 255.255.255.0 to a /20 mask 255.255.240.0 on all devices on that ethernet segment. All remote segments are on a unique ip subnet and the 0.x address space has been increased in size from 2^8 to 2^12.

sprkymrk · July 2007

I give up.

Netstudent · July 2007

It looks to me like sprkymrk has the best solution. All you would have to do is change the subnet masks on all your hosts and add the new hosts to the larger subnet. Unless you are already using 192.168.1.0 some where else. IN which case you would have an overlap. you would probably have to chnage the network in the routing protocol or any static routes that are setup. If you have any external DNS or external public IP's that are pointing to your servers in that subnet, those records might need a little fixing too.

dtlokee · July 2007

The quick and dirty solution would be to implement a secondary address on the router that has the full subnet to create another subnet of 254 addresses, but the more correct way would involve re-addressing the entire range so it would be in a range of contigious addresses, for example 192.168.12.0/23 which would be a range from 192.168.12.1 - 192.168.13.254. or if the 192.168.1.0/24 range has few hosts on it, you could move them to another range like 192.168.12.0/24 and then supernet 192.168.0.0/24 and 192.168.1.0 /24 using the 192.168.0.0/23 address.

datchcha · July 2007

sprkymrk wrote:

sprkymrk wrote:

Add the extra hosts on 192.168.1.0 and then make all your hosts (.0 and .1) use a 255.255.254.0 netmask. You'll have a bigger broadcast domain, but it shouldn't bog down a modern network.

Like I said way back.... do it like this and it WILL work. Just use contiguous network numbers for the 255.255.254.0 mask to work. So if you are currently using 192.168.0.0, make your new one 192.168.1.0. Use a mask of 255.255.254.0 on all your clients. Not sure what is so confusing about this. You don't need a layer three switch, you don't need a router, you don't need to supernet, you don't need a VLAN. All those things are nicer ways to do it, but you said you can't implement those so just configure the clients as stated above and you'll be fine.

I understand what you are saying. I am not sure, but you have to update your DHCP server?

sprkymrk · July 2007

datchcha wrote:

sprkymrk wrote:

sprkymrk wrote:

Add the extra hosts on 192.168.1.0 and then make all your hosts (.0 and .1) use a 255.255.254.0 netmask. You'll have a bigger broadcast domain, but it shouldn't bog down a modern network.

Like I said way back.... do it like this and it WILL work. Just use contiguous network numbers for the 255.255.254.0 mask to work. So if you are currently using 192.168.0.0, make your new one 192.168.1.0. Use a mask of 255.255.254.0 on all your clients. Not sure what is so confusing about this. You don't need a layer three switch, you don't need a router, you don't need to supernet, you don't need a VLAN. All those things are nicer ways to do it, but you said you can't implement those so just configure the clients as stated above and you'll be fine.

I understand what you are saying. I am not sure, but you have to update your DHCP server?

Yes, add the new scope (you can make it a superscope if you want, but you don't have to) and change the subnet mask that it hands out to 255.255.254.0.

a network problem....

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