Why different network IP will not ping in L2 switch

[Muhammad Thanveer]

Hello,

i have a query,

When we have different network IPs connected to a L2 switch in same broadcast domain we will not be able to ping why?

PC1(192.168.1.1/24)----->SW1------->PC2(192.168.2.1/24)

I know that L2 switch cannot understand L3 protocol. Now when we try to ping from 192.168.1.1 to 192.168.2.1 switch broadcast, why the PC 192.168.2.1 will not respond, need some background. Please help.

[ashirkar]

Hi Thanveer .

PC has ARP table(Go to cmd and type arp then give space and pres enter) ,when you ping out of your subnet ,you need to reachout to gateway,thts why when you don't configure gateway you wont be able to reach network out site of your subnet.

There is another way to reach out of your subnets by configuring static route in PC 

syntax:

route add 4.4.4.4 mask 255.255.255.255 192.168.0.1 

please refer microsoft link

http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sag_tcpip_pro_addstaticroute.mspx?mfr=true

Regards,

Ashish

[Muhammad Thanveer]

Ashirkar,

If i understood properly you meant to say that since the broadcast domains are different and when we need to reach out to the different broadcast domains we require a gateway?

BR

Thanveer

[ashirkar · Accepted solution]

Hi Thanveer,

Your question is your answer !!!

Let's say, if we have L2 switches and we created 2 vlan on it, will they able to community with each other? No, Why? Because MAC address is only allow to communicate on a broadcast segment. So anything which is outside of your subnet need to know either by providing route information to it or giving gateway location that will reach you to that destination.

PC does same like your other devices.

On the router, you can ping to the devices that are connected to it because they are on same LAN segment but you won’t ping device which is some hope away from same router, why? , because, you don’t know how to reach them.

Why do we configure default route point to internet, just to provide routing information to router about the network which is not part of it .Isn't that fair :) 

Hope you understand 

Regards,

Ashish

[Muhammad Thanveer]

Fair enough Ashish, thanks