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Lab question: How to create subnets for one local ISP public IPv4 address given
Rodzilla G
Member Posts: 82 ■■□□□□□□□□
in CCNA & CCENT
Ok,
This is a lab question involving 4 routers, each at different locations. This business has one public IPv4 IP address given which is 70.246.128.27/24. The author instructs the network engineer to create subnets for the 4 point-to-point connections between these 4 business locations. (I have an attached crude looking PDF outline I made using packet tracer).
First, I know there are many different ways that others can probably solve this problem. And although I appreciate many perspectives of what else should be done...I want to stick to trying to solve this lab in accordance with what the author asks for.
My question is: Is it possible to take this /24 public IP address and break it down into a /27 for VLSM...and still have each of the 4 locations still see the one public ip address? I thought of the /27 based on not only the 4 p2p connections, but also the 4 networks, for a total of 8 networks...thus the /27.
Am I way off base here?? Or am I on the right track?? And if I am going in the right direction, I simply can't figure out how to give each location these subnets without involving NAT and/or PAT....which the author does not say to use. The only hint he gives is to "break the given /24 mask into smaller subnets)
Any suggestions are GREATLY appreciated.
This is a lab question involving 4 routers, each at different locations. This business has one public IPv4 IP address given which is 70.246.128.27/24. The author instructs the network engineer to create subnets for the 4 point-to-point connections between these 4 business locations. (I have an attached crude looking PDF outline I made using packet tracer).
First, I know there are many different ways that others can probably solve this problem. And although I appreciate many perspectives of what else should be done...I want to stick to trying to solve this lab in accordance with what the author asks for.
My question is: Is it possible to take this /24 public IP address and break it down into a /27 for VLSM...and still have each of the 4 locations still see the one public ip address? I thought of the /27 based on not only the 4 p2p connections, but also the 4 networks, for a total of 8 networks...thus the /27.
Am I way off base here?? Or am I on the right track?? And if I am going in the right direction, I simply can't figure out how to give each location these subnets without involving NAT and/or PAT....which the author does not say to use. The only hint he gives is to "break the given /24 mask into smaller subnets)
Any suggestions are GREATLY appreciated.
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TechGuru80
Member Posts: 1,539 ■■■■■■□□□□
I would think you would want /30 to conserve address space and limit the network to the two connections on each. How the question is worded you would have .1 to .254 (/24) and they would all be public without the need to pat/nat...I am assuming you were thinking the .27 was /32. -
OptionsExabyte
Member Posts: 11 ■□□□□□□□□□
You have only ONE IPv4 address. How you can break it for four locations? You HAVE to use "gray" addresses on your routers to create connections and on one of them create NAT (PAT with overload).
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Optionstheodoxa
Member Posts: 1,340 ■■■■□□□□□□
You have only ONE IPv4 address. How you can break it for four locations? You HAVE to use "gray" addresses on your routers to create connections and on one of them create NAT (PAT with overload).
If this is a single address, then you would need a hub a spoke topology with a single hub site connected to the other [spoke] sites. The links between sites would have to use RFC 1918 (Private) IP Addresses and the Hub Router would have to perform PAT (NAT Overload) to allow everyone out to the internet.R&S: CCENT → CCNA → CCNP → CCIE [ ]
Security: CCNA [ ]
Virtualization: VCA-DCV [ ] -
Optionstheodoxa
Member Posts: 1,340 ■■■■□□□□□□
Was the topology you gave included in the question or something you came up with?
R&S: CCENT → CCNA → CCNP → CCIE [ ]
Security: CCNA [ ]
Virtualization: VCA-DCV [ ] -
OptionsRodzilla G
Member Posts: 82 ■■□□□□□□□□
This is what I thought too...but the author didn't mention using that within his "hint"...so I was thinking...am I wrong to think NAT/PAT??? Thanks for confirming what I was thinking.You have only ONE IPv4 address. How you can break it for four locations? You HAVE to use "gray" addresses on your routers to create connections and on one of them create NAT (PAT with overload).
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OptionsRodzilla G
Member Posts: 82 ■■□□□□□□□□
Thank you thank you thank you!!! I kept thinking pat/nat....but the author would only mention breaking it down into 4 subnets. This helps me tremendously!!! A hub and spoke, now I can clearly do that. Just wanted to bounce this off of others. Thanks again!If this is a single address, then you would need a hub a spoke topology with a single hub site connected to the other [spoke] sites. The links between sites would have to use RFC 1918 (Private) IP Addresses and the Hub Router would have to perform PAT (NAT Overload) to allow everyone out to the internet.
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OptionsRodzilla G
Member Posts: 82 ■■□□□□□□□□
It was included into the lab question. And yes looks similar to that. It was one business with 4 locations with one Public IP Address.
But reviewing the answers...it confirmed what I thought, which is to PAT this out in a hub and spoke.Was the topology you gave included in the question or something you came up with?
