Subnetting

[omegabetax]

Hi,

I have 3 routers(R1 with s0,s1,e0,R2 and R3 with s0,e0) directly connected to 3 switches that have up to 8 PCs. Having a class B addresses 190.30.5.0 /24 I want to subnet this class so that ajust it to my needs.
I've tried with 190.30.5.0 /28 and the result is that I can use the following subnets:

190.30.0.16 /28 for what is back to R1
190.30.0.32 /28 for what is back to R2
190.30.0.48 /28 for what is back to R3
for R1-s1 190.30.0.16 /28

Because R1 has 2 serial interfaces I must use different subnets. The problem is that R1s0 and R2s0 , R1s1 and R3s0 must be on the same subnet. So the adsress are a little bit mixed.

Can someone advice me what steps must I do to reach my goal?

Thanks

 

[CiscoGuy33]

omegabetax,

Not real clear exactly what you are asking but you could use -

190.30.5.4 /30 for R1 S0 to R2 S1
Network is 190.30.5.4
R1 S0 - 190.30.5.5
R2 S1 - 190.30.5.6
Broadcast - 190.30.5.7

190.30.5.8/30 for R1 S1 to R3 S0
Network is 190.30.5.8
R1 S1 - 190.30.5.9
R3 S0 - 190.30.5.10
Broadcast - 190.30.5.11

190.30.5.12/30 for R2 S0 to R3 S1
Network is 190.30.5.12
R1 S0 - 190.30.5.13
R2 S1 - 190.30.5.14
Broadcast - 190.30.5.15

190.30.5.16/28 for R1 E0
Network is 190.30.5.16
computers are 190.30.5.17-30
Broadcast is 190.30.5.31

190.30.5.32/28 for R2 E0
Network is 190.30.5.32
computers are 190.30.5.33-46
Broadcast is 190.30.5.47

190.30.5.48/28 for R3 E0
Network is 190.30.5.48
computers are 190.30.5.49-62
Broadcast is 190.30.5.63

I hope this helps!




E.A. Broda
CCNA, CCDA, CCAI, Network +