Private IP range

anthrg · 08-13-2006, 12:52 AM

Hi,

A basic query....

If I have 2 systems with IP address as follows, will they be able to communicate with each other if connected to the same switch?

192.168.1.X 255.255.255.0

192.168.2.X 255.255.255.0

Generally put if one system is in the network range 192.168.1.1 to 192.168.1.255 and the other in 192.168.5.1 to 192.168.5.255, is it possible to have communication between the two without a managed switch or Router?

regards

Ananth

Elbatrop1 · 08-13-2006, 01:08 AM

First off, I deleted your other thread, as it was a duplicate of this one and was not needed.

Second, to answer your question, no. Because the 2 IPs are in different networks with different network IPs, then they are not able to communicate without a router.

anthrg · 08-13-2006, 01:17 AM

Elbatrop1,Thanks for the prompt response!

Can a Layer 3 switch be used instead of the Router?

Law · 08-13-2006, 10:44 AM

Sure you can, but layer 3 switches are quite expensive, why? because they have optimized hardware to pass data as fast as Layer 2 switches, yet they make decisions on how to transmit traffic at Layer 3, just like a router. Within the LAN environment, a Layer 3 switch is usually faster than a router because it is built on switching hardware. In fact, many of Cisco's Layer 3 switches are actually routers that operate faster because they are built on "switching" hardware with customized chips inside the box.

If you have two computer in different networks, on the same switch, take for example:

PC1 IP: 192.168.1.100 /24
PC1 Network: 192.168.1.0 /24
PC2 IP: 192.168.2.200 /24
PC2 Network: 192.168.2.0 /24

PC1 does not know the path to the network 192.168.2.0, therefore all traffic that doesn't match it's network (define by the prefix 0.0.0.0 / 0.0.0.0) will be forwarded out the default gateway (to the router, to handle the network issue). This prefix is use for the Internet, so that the computer routing table doesn't have to keep every information about every network on the Internet. Same goes with PC2.

In order to have both PC communicating, you tell it where the network is by giving it a static route in it's routing table.

For PC1, if this is a Windows machine, you add a route by typing
route add 192.168.2.0 mask 255.255.255.0 192.168.1.100 metric 20

PC2:
route add 192.168.1.0 mask 255.255.255.0 192.168.2.200

route add= is the command to add a static route
192.168.1.0 =is the destination in PC2 case
mask= is the command that define the subnet mask
255.255.255.0= is the subnet mask
192.168.2.200= is the default gateway, in PC2 case it's its own interface that is conneted to the switch.
metric=is the command that define the metric in PC1 case(the lower it is the higher the priority to use it).
20= is the metric number define by me, the lower it is, the higher the priority.

Notice that I didn't use a metric for PC2, you don't really need to, you can let windows do that. It will determine for you base on your connection type.
20 for 100Mbps
25 for 802.11G
30 for 10Mbps
etc.

To see your routing table, type route print, to delete a route in PC1 case type route delete 192.168.2.0

This fundamental applies to all OS, but the commands are just different.

For more information look at http://www.microsoft.com/resources/d....mspx?mfr=true

anthrg · 08-13-2006, 12:58 PM

Thank You Law, I actually read some other replies of you and was hoping you would post a reply to my query....

Thank you very much....great help at the right time...

Thanks to both of you Elbatrop1 and Law!!

08-13-2006, 12:52 AM	#1 (permalink)
anthrg Newb Techie Join Date: Aug 2006 Posts: 3	Private IP range Hi, A basic query.... If I have 2 systems with IP address as follows, will they be able to communicate with each other if connected to the same switch? 192.168.1.X 255.255.255.0 192.168.2.X 255.255.255.0 Generally put if one system is in the network range 192.168.1.1 to 192.168.1.255 and the other in 192.168.5.1 to 192.168.5.255, is it possible to have communication between the two without a managed switch or Router? regards Ananth

08-13-2006, 01:08 AM	#2 (permalink)
Elbatrop1 Memberbot Join Date: Mar 2004 Posts: 4,059	First off, I deleted your other thread, as it was a duplicate of this one and was not needed. Second, to answer your question, no. Because the 2 IPs are in different networks with different network IPs, then they are not able to communicate without a router. __________________ Intel E6750...........PSN: ELBATROP XFX nForce 650i Ultra Kingston PC2-6400 2GB eVGA 9800GT 36GB WD Raptor 120GB SG 250GB WD Logitech X-530 Samsung SyncMaster 931c Samsung SyncMaster 750s

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

08-13-2006, 01:17 AM	#3 (permalink)
anthrg Newb Techie Join Date: Aug 2006 Posts: 3	Elbatrop1,Thanks for the prompt response! Can a Layer 3 switch be used instead of the Router?

08-13-2006, 10:44 AM	#4 (permalink)
Law Wizard Techie Join Date: Aug 2005 Posts: 4,171	Sure you can, but layer 3 switches are quite expensive, why? because they have optimized hardware to pass data as fast as Layer 2 switches, yet they make decisions on how to transmit traffic at Layer 3, just like a router. Within the LAN environment, a Layer 3 switch is usually faster than a router because it is built on switching hardware. In fact, many of Cisco's Layer 3 switches are actually routers that operate faster because they are built on "switching" hardware with customized chips inside the box. If you have two computer in different networks, on the same switch, take for example: PC1 IP: 192.168.1.100 /24 PC1 Network: 192.168.1.0 /24 PC2 IP: 192.168.2.200 /24 PC2 Network: 192.168.2.0 /24 PC1 does not know the path to the network 192.168.2.0, therefore all traffic that doesn't match it's network (define by the prefix 0.0.0.0 / 0.0.0.0) will be forwarded out the default gateway (to the router, to handle the network issue). This prefix is use for the Internet, so that the computer routing table doesn't have to keep every information about every network on the Internet. Same goes with PC2. In order to have both PC communicating, you tell it where the network is by giving it a static route in it's routing table. For PC1, if this is a Windows machine, you add a route by typing route add 192.168.2.0 mask 255.255.255.0 192.168.1.100 metric 20 PC2: route add 192.168.1.0 mask 255.255.255.0 192.168.2.200 route add= is the command to add a static route 192.168.1.0 =is the destination in PC2 case mask= is the command that define the subnet mask 255.255.255.0= is the subnet mask 192.168.2.200= is the default gateway, in PC2 case it's its own interface that is conneted to the switch. metric=is the command that define the metric in PC1 case(the lower it is the higher the priority to use it). 20= is the metric number define by me, the lower it is, the higher the priority. Notice that I didn't use a metric for PC2, you don't really need to, you can let windows do that. It will determine for you base on your connection type. 20 for 100Mbps 25 for 802.11G 30 for 10Mbps etc. To see your routing table, type route print, to delete a route in PC1 case type route delete 192.168.2.0 This fundamental applies to all OS, but the commands are just different. For more information look at http://www.microsoft.com/resources/d....mspx?mfr=true

08-13-2006, 12:58 PM	#5 (permalink)
anthrg Newb Techie Join Date: Aug 2006 Posts: 3	Thank You Law, I actually read some other replies of you and was hoping you would post a reply to my query.... Thank you very much....great help at the right time... Thanks to both of you Elbatrop1 and Law!!