Internal vs. External IP Address to use?

[Bluefin30]

Hello,

I am a newbie in networking domain so I'll keep my question very simple and short. At my work we have 10 PC, one of those 10 PCs have to be selected as a dedicated PC to download large files from a Vendor's FTP site. The Vendor is asking us to provide "IP Network Range" for them to which PC or user will be logging in to their FTP side for security reason.

My question is do I need to provide them the External IP Address which is a single address for all the request going out? or else.

Does providing internal IP Address of the selected PC even makes any sense...?

Please Advise.

 

[Rifter]

Hello,

I am a newbie in networking domain so I'll keep my question very simple and short. At my work we have 10 PC, one of those 10 PCs have to be selected as a dedicated PC to download large files from a Vendor's FTP site. The Vendor is asking us to provide "IP Network Range" for them to which PC or user will be logging in to their FTP side for security reason.

My question is do I need to provide them the External IP Address which is a single address for all the request going out? or else.

Does providing internal IP Address of the selected PC even makes any sense...?

Please Advise.

They want your WAN IP, the one they will see on their end as accessing their server.

 

[Bluefin30]

Thanks Rifter,

To get to that WAN IP should I use the following site from any of the 10 PCs in the LAN?

http://www.whatismypublicip.com/

 

[Rifter]

yes that will work, note though that if its not a static IP, then you will need to provide them with a range of IP's that your ISP uses for your connection. This is why they originally asked for a range.

 

[Bluefin30]

Thanks Rifter

Yes, they have asked us to provide the range and I do not know how to locate the range...is there any command you can use in the cmd to get to show the range values...?

 

[Kartajan]

the range should be all but the last set of numbers.
For example if you have 192.168.0.1 as a public IP, your range should be at most 192.168.0.1 to 192.168.0.255

(Note this example will never be a public IP)

 

[razel]

No command. That range is provided by your network team. In fact at this point, it's best for them to provide the info. I'd explain to them what you need. In my office, if they saw such a port spewing out files without them knowning, they'll shut it down. If your network team says that one IP is fine, then the range you provide is that IP address for start and end.

 

[Rifter]

exactly its usually just the last set that will change but not always. You can simply email your ISP and they will be able to provide you with this info very easily.

 

[JackMDS]

The question indicate that your knowledge of Networking is beyond par and you are risking the security of your Network.

I would suggest seeking a consultant advise. Solving issues like this via Public Forums is Not the way to go.

 

[Bluefin30]

The question indicate that your knowledge of Networking is beyond par and you are risking the security of your Network.

I would suggest seeking a consultant advise. Solving issues like this via Public Forums is Not the way to go.

Thanks JackMDS,

Security is a concern that's why we need to provide the Vendor the IP Range...unfortunately I am the only guy handling this, we are small firm and all the network setup was done by an employee who have left us and there is no documentation whatsoever.

 

[Bluefin30]

the range should be all but the last set of numbers.
For example if you have 192.168.0.1 as a public IP, your range should be at most 192.168.0.1 to 192.168.0.255

(Note this example will never be a public IP)

Thanks Kartajan,

How I can get access to the IP Range information and how I would know if the IP being broadcast is a Static or Dynamic IP?

 

[Kartajan]

Thanks Kartajan,

How I can get access to the IP Range information and how I would know if the IP being broadcast is a Static or Dynamic IP?

Ask your ISP. Usually (but not always) a static IP has an additional charge.
And you really should get a knowledgeable person to manage your network either via a consultant per JackMDS or a local hire....

 

[Bluefin30]

Ask your ISP. Usually (but not always) a static IP has an additional charge.
And you really should get a knowledgeable person to manage your network either via a consultant per JackMDS or a local hire....

Thanks, I checked the External IP by logging into 3 PCs on the LAN and every instance I got the same External IP Address:

i.e. by using:http://www.whatismypublicip.com/

Now does that mean the External IP is a Static IP?

 

[mxnerd]

Thanks, I checked the External IP by logging into 3 PCs on the LAN and every instance I got the same External IP Address:

i.e. by using:http://www.whatismypublicip.com/

Now does that mean the External IP is a Static IP?

Even if you have 100 local PC telling you have same WANP IP, you can't tell if an WAN IP is static or dynamic via those kind of sites.

Either ask your ISP or login into your router, you will see the setup info.

ISP usually will charge you by how many static IP addresses you get. If the business pay 5 static IP addresses, then that's the range. If the business only have one static IP, just tell the vendor the businees only have one IP address.

The reason your vendor asking you the IP range is they will configure firewall rules so that only devices in that range will be allowed to login.

If your router or firewall only get dynamic IP, then you just give your vendor a range like xxx.yyy.zzz.0, because that's usually how ISP configure the DHCP, where xxx.yyy.zzz are the first 3 numbers from your public IP address.

 

[Kartajan]

I stated calling the ISP because that is the only way to be sure. A good number of ISP modems will hide critical information such as if DCHP is in use.

 

[Bluefin30]

Even if you have 100 local PC telling you have same WANP IP, you can't tell if an WAN IP is static or dynamic via those kind of sites.

Either ask your ISP or login into your router, you will see the setup info.

ISP usually will charge you by how many static IP addresses you get. If the business pay 5 static IP addresses, then that's the range. If the business only have one static IP, just tell the vendor the businees only have one IP address.

The reason your vendor asking you the IP range is they will configure firewall rules so that only devices in that range will be allowed to login.

If your router or firewall only get dynamic IP, then you just give your vendor a range like xxx.yyy.zzz.0, because that's usually how ISP configure the DHCP, where xxx.yyy.zzz are the first 3 numbers from your public IP address.

Thanks,

So for me to be sure I have two options:

1. Call the ISP
2. Login to the ISP's provided Router and get to the setup page.

In case where IP is dynamic, provide the Vendor xxx.yyy.zzz (i.e. first 3 numbers) which I suppose will be sourced from either of the options 1 and 2 I listed above.

To be more specific the Vendor is migrating from a legacy server which was used as a FTP Server to a new Server, but now since they are configuring the Server they want to make sure they set it up as such so they have tractability of who logged in and what is downloaded.

 

[Bluefin30]

I stated calling the ISP because that is the only way to be sure. A good number of ISP modems will hide critical information such as if DCHP is in use.

I will call the ISP tomorrow and let you guys know what I find out.

 

[mxnerd]

As many have suggested, calling the ISP is the best way to find out full info. Since if your business bought multiple static IP addresses, you usually can't find it out in router setup.

 

[Bluefin30]

Thanks Guys,

I did call the ISP and get all the requirement info such as:
External IP Address (We have Static IP)
Gateway IP
Subnet Mask
Primary DNS
Secondary DNS

This is all I think will be needed to provide to the Vendor.

 

[JackMDS]

LOL, if you do have Static Internet IP and your external provider made their "demands" as described above.

Then they are in dire need of Consultant even more than your enterprise.

 

[Red Squirrel]

Now is also a good time to document the info so that you have it next time. I'd suggest labeling it on the ISP's equipment like modem etc. Got going to a site like ipchicken.com or something would also show you your IP.