Need Help With Subnetting

[LivLogik]

Hello i get the gist of subnetting but i was wondering if someone could help me. I am trying to do this school lab and i dont understand where im going wrong. im attaching the pdf of the lab. i have to get host 2 to ping to host 1.

I can get host 1 to ping with the dallas router but no farther and the i can get host 2 to ping to the dallas router but wont go any farther.

here is what i have set up so far --->

I used a subnet of 255.255.255.192

Here are the IPs and subnet I'm using and i have listed it from left to right --->


__________________________________________________ ___

Host 1 :

IP(192.168.16.2) - Sub(255.255.255.192)
Gateway : 192.168.1.1


DALLAS SWITCH


Dallas Router :

IP(192.168.16.1) - Sub(255.255.255.192)
Serial 0/0/0 : IP(192.168.16.193) - Sub(255.255.255.192)

Static : IP(192.168.16.64) - Sub(255.255.255.192) - Next Hop(192.168.16.194)



Raleigh Router :

IP(192.168.16.65) - Sub(255.255.255.192)
Serial 0/0/0 : IP(192.168.16.194) - Sub(255.255.255.192)

Static : IP(0.0.0.0) - Sub(0.0.0.0) - Next Hop(192.168.16.193)


RALEIGH SWITCH


Host 2 :

IP(192.168.16.66) - Sub(255.255.255.192)
Gateway : 192.168.1.1

__________________________________________________ ___

It will ping from host 2 all the way to the Dallas Router but it will not go to Host 1 for some reason.

Also when I try to ping the gateway for host 1 for some reason it won't ping and times out and when I try to ping the gateway for host 2 it says it can't be reached.

From left to right it goes

Host 1
Dallas Switch
Dallas Router
Raleigh Router
Raleigh Switch
Host 2


Please let me know if you have any ideas any help will but super appreciated!

Thanks,

Zach

Lab ----> https://drive.google.com/file/d/0B0iYPEw18PuibmRiZndrSHhSeGc/view?usp=docslist_api

 

[Pandasaurus]

I didn't read the documents, but if we can assume the two pictured interfaces are the ends of the link between the two routers, you need to check your subnetting math. You're a bit off on the Raleigh end.

 

[LivLogik]

I didn't read the documents, but if we can assume the two pictured interfaces are the ends of the link between the two routers, you need to check your subnetting math. You're a bit off on the Raleigh end.

No sorry I should have posted a better picture with host 1and host 2 into but the ones in the picture are the routers.

I changed up the number though.

I used a subnet of 255.255.255.192

Here are the IPs and subnet I'm using and i have listed it from left to right --->


_____________________________________________________

Host 1 :

IP(192.168.16.2) - Sub(255.255.255.192)
Gateway : 192.168.1.1


DALLAS SWITCH


Dallas Router :

IP(192.168.16.1) - Sub(255.255.255.192)
Serial 0/0/0 : IP(192.168.16.193) - Sub(255.255.255.192)

Static : IP(192.168.16.64) - Sub(255.255.255.192) - Next Hop(192.168.16.194)



Raleigh Router :

IP(192.168.16.65) - Sub(255.255.255.192)
Serial 0/0/0 : IP(192.168.16.194) - Sub(255.255.255.192)

Static : IP(0.0.0.0) - Sub(0.0.0.0) - Next Hop(192.168.16.193)


RALEIGH SWITCH


Host 2 :

IP(192.168.16.66) - Sub(255.255.255.192)
Gateway : 192.168.1.1

_____________________________________________________

It will ping from host 2 all the way to the Dallas Router but it will not go to Host 1 for some reason.

Also when I try to ping the gateway for host 1 for some reason it won't ping and times out and when I try to ping the gateway for host 2 it says it can't be reached.

From left to right it goes

Host 1
Dallas Switch
Dallas Router
Raleigh Router
Raleigh Switch
Host 2

 

[Pandasaurus]

Gateway address needs to be the IP of the actual gateway (IE: the closet router interface, in this example). Currently, you list both hosts having the same gateway (192.168.1.1), which is not assigned to anything. Beyond that, I'm not seeing any glaring errors in the IP configuration as it was posted, but I'm tired, and there is always the possibility something is different in the actual configuration.

 

[LivLogik]

Gateway address needs to be the IP of the actual gateway (IE: the closet router interface, in this example). Currently, you list both hosts having the same gateway (192.168.1.1), which is not assigned to anything. Beyond that, I'm not seeing any glaring errors in the IP configuration as it was posted, but I'm tired, and there is always the possibility something is different in the actual configuration.

thanks for replying back! so would the gateway be something like 192.168.16.3 for host 1 and 192.168.16.67 for host 2?

also i thought the gateways for host 1 and host 2 need to be the same so they can talk to each other.

sorry if im keeping you up

 

[Pandasaurus]

For any given host, the gateway (default gateway, or gateway of last resort, depending on vendor) needs to be the address of the closest device that is routing at layer 3. The gateway address is where the host will send packets when it does not know how to get to the destination. If the gateway is on another network, it won't be able to communicate, as it won't know how to get to that network. Assuming you are taking a class and not self-learning, I would suggest asking your instructor for more explanation of the routing process. It's better to ask questions in class, because it helps everybody in the class (well, except that girl at the end of the row playing Farmville instead of paying attention... She's beyond help. And no, I'm not joking. That happened).

Most instructors are more than willing to provide hints to a test if you ask the right questions. (IE: Rather than ask "What should I do here?", tell this instructor "I tried this, but it didn't work. Why not?") When you ask a question in a form that tells the instructor that you made your best effort, and were paying attention, but don't quite "get it", they'll typically either answer your question with a question that tells you the answer, or give you a subtle hint as to where to look for your problem.

 

[MtnMan]

Stop doing his homework for him!

Convert to binary, manipulate the bits, convert back to decimal. Done

 

[LivLogik]

im self learning right now but i am going to be going to school in april and want to be on top of the game haha. My friend is in school and let me have the pdf to his lab. He is having trouble with this too.

thanks for your responses

ill try to add host 1 gateway onto the dallas router network and host 2 on the Raleigh router network and see what happens

 

[Pandasaurus]

Stop doing his homework for him!

Convert to binary, manipulate the bits, convert back to decimal. Done

I'm actually trying to avoid doing just that. Not everyone learned everything there is to networking in their first class or book. Some people need a push in the right direction when they don't know an answer. I know I did, more than once.

 

[LivLogik]

I'm actually trying to avoid doing just that. Not everyone learned everything there is to networking in their first class or book. Some people need a push in the right direction when they don't know an answer. I know I did, more than once.

thank you again Pandasaurus ill try and see what i can do i dont think me changing host 1 gateway to .3 and host 2 gateway to .167 worked.

Thanks again !

 

[LivLogik]

If somebody could help me. i dont care if you give me the answers or not. i just want to know the math and steps to figure out what the Gateway IP are and then i will do it from there. Any help would be very very appreciated

 

[Pandasaurus]

You already know the gateway IP. As I said previously, the gateway IP for a given host is the IP of the closest device that is routing at layer 3. There is no math that can tell you for certain what the gateway address is for any given host or network. You can make an educated guess (the vast majority of people use the first available address on the subnet, but I've seen cases where people used other addresses for one reason or another), but you can't know for certain with only math.

 

[LivLogik]

You already know the gateway IP. As I said previously, the gateway IP for a given host is the IP of the closest device that is routing at layer 3. There is no math that can tell you for certain what the gateway address is for any given host or network. You can make an educated guess (the vast majority of people use the first available address on the subnet, but I've seen cases where people used other addresses for one reason or another), but you can't know for certain with only math.

THANK YOU THANK YOU THANK YOU!!!

i used the gateway 192.168.16.1 for host 1 and host 2 and they are talking now!

i didnt understand that i could use the Dallas Router IP for the the gateway for both computers i thought it had to be its own IP!

Thanks so much.

is it always like that like say the router is 192.168.26.1 i could make the gate way the same ? sorry for the questions im just trying to understand it

 

[MtnMan]

If somebody could help me. i dont care if you give me the answers or not. i just want to know the math and steps to figure out what the Gateway IP are and then i will do it from there. Any help would be very very appreciated

The secret to subnetting including VLSMs is to convert to binary, manipulate the bits, then convert pack to decimal.

 

[LivLogik]

The secret to subnetting including VLSMs is to convert to binary, manipulate the bits, then convert pack to decimal.

thanks yeah i got the converting i think and stuff i think it was just the gateway that was killing me and i didnt understand lol.

 

[Pandasaurus]

The secret to subnetting including VLSMs is to convert to binary, manipulate the bits, then convert pack to decimal.

You can convert to binary and back to decimal until the end of time, that won't tell you what the default gateway address is, or why you need one. As I said previously, it may give you an educated guess, but math cannot tell you what your default gateway address is, only what it might be (the first usable address on the subnet, which may not be the case). And knowing the address still doesn't explain to somebody new to networking what the default gateway does, and why you need one (on the same network).

THANK YOU THANK YOU THANK YOU!!!

i used the gateway 192.168.16.1 for host 1 and host 2 and they are talking now!

i didnt understand that i could use the Dallas Router IP for the the gateway for both computers i thought it had to be its own IP!

Thanks so much.

is it always like that like say the router is 192.168.26.1 i could make the gate way the same ? sorry for the questions im just trying to understand it

So, I'm trying to explain how things work, without actually telling you the answer. Learning the answer yourself typically makes it easier to remember long term, rather than having someone tell you the answer. The only explanation I can come up with for why your current configuration works, is that host 2 is somehow getting it's packets to Raleigh, and because Raleigh has a default (all zeroes) route, it's sending everything to Dallas anyways. A host having it's default gateway on a separate network should not work correctly (in fact, Windows will warn you before allowing you to save that configuration). The default gateway is the "exit" from the network the host is on. If you're in a building, and you want to get out, you look for the exit. Knowing where the exit is in the building across the street won't help you, you aren't across the street. You need to know where the exit is in the building (network) you are in is.

 

[LivLogik]

gotcha i think i get it. i understand you not giving me the answer i prefer it that way anyways. i like to learn.

Thank you all for the help!! i really really appreciate it.