Question Question about IPs?

[htinvestbg]

Server operating system version

Linux

Plesk version and microupdate number

Latest

Hi,

1. My ISP gave me 1 static IP address, but they said that it's going to work only using DHCP since they can't give me netmask and gateway - is this going to be a problem for Plesk?
2. Is there a way to use only this 1 static IP address for multiple machines - I'll buy a licence for each one of course?

Thanks!

 

[scsa20]

1. My ISP gave me 1 static IP address, but they said that it's going to work only using DHCP since they can't give me netmask and gateway - is this going to be a problem for Plesk?

Are you running this from your home network? Only in a home network something like that would happen. Assuming that the static IP is, truly, static, then it's fine running off of DHCP but key is making sure that the IP does not change and assuming that the IP is actually a publicly accessible IP address.

2. Is there a way to use only this 1 static IP address for multiple machines - I'll buy a licence for each one of course?

Yes and no, and let me explain why it's both.

First off, I'm presuming that the static IP is assigned to a hardware firewall, the firewall will need to have port forwarding enabled to pass traffic from port 80, 443, etc. to your actual server hosting.

Now this is where the Yes part comes in, if it is assigned to a hardware firewall you could, technically speaking, configure it so that you could, say, forward port 81 to the second server but doing that means that whoever is going to the site will also need to include :81 in the address which is not something normal users will know to do.

The alternative method which also requires more work to do and more complexity to set up is to put a load balancer (like KEMP) in front of the servers and behind the firewall. The firewall's port forwarding should be configured to forward the proper traffic to the load balancer, the load balancer should then have a list of hosts it's expecting from which you can then forward said traffic to the proper server that is hosting the site. Again, this is more complex as you now have 2 locations you need to add domain names to.

As for the no part, if the static IP is slapped directly to the server, then no, you're not going to be able to use the IP on multiple machines as you will just have a conflict.

Likewise, if you do not want to use a load balancer nor use alternative ports (meaning you don't want your users to remember to use port 81 to get to server b) then this is also a hard no.

Basically what I'm trying to say is, if you're planning on using multiple servers, I would suggest getting multiple public static IPs as that would be easier to deal with then using a single IP when it comes to working with multiple servers that needs public facing access. (The load balancer is still the best option if you're stuck with just 1 IP and don't mind getting your hands dirty with the configurations).

 

[htinvestbg]

Are you running this from your home network? Only in a home network something like that would happen. Assuming that the static IP is, truly, static, then it's fine running off of DHCP but key is making sure that the IP does not change and assuming that the IP is actually a publicly accessible IP address.

Yes and no, and let me explain why it's both.

First off, I'm presuming that the static IP is assigned to a hardware firewall, the firewall will need to have port forwarding enabled to pass traffic from port 80, 443, etc. to your actual server hosting.

Now this is where the Yes part comes in, if it is assigned to a hardware firewall you could, technically speaking, configure it so that you could, say, forward port 81 to the second server but doing that means that whoever is going to the site will also need to include :81 in the address which is not something normal users will know to do.

The alternative method which also requires more work to do and more complexity to set up is to put a load balancer (like KEMP) in front of the servers and behind the firewall. The firewall's port forwarding should be configured to forward the proper traffic to the load balancer, the load balancer should then have a list of hosts it's expecting from which you can then forward said traffic to the proper server that is hosting the site. Again, this is more complex as you now have 2 locations you need to add domain names to.

As for the no part, if the static IP is slapped directly to the server, then no, you're not going to be able to use the IP on multiple machines as you will just have a conflict.

Likewise, if you do not want to use a load balancer nor use alternative ports (meaning you don't want your users to remember to use port 81 to get to server b) then this is also a hard no.

Basically what I'm trying to say is, if you're planning on using multiple servers, I would suggest getting multiple public static IPs as that would be easier to deal with then using a single IP when it comes to working with multiple servers that needs public facing access. (The load balancer is still the best option if you're stuck with just 1 IP and don't mind getting your hands dirty with the configurations).

Thank you for your help!

About the DHCP - It's a business building, gigabit fiber PPPoE, and the ISP told me that the IP is static, but I need to get it using DHCP, since the netmask and gateway are dynamic. That's the first time I'm hearing about dynamic netmask and gateway. So I was wondering if Plesk can work using DHCP.

About the IPs - I actually decided each server to have a separate contract with static IP, so that should be fine.

 

[Peter Debik]

So I was wondering if Plesk can work using DHCP.

Plesk won't do anything with network settings. Your network interface needs to be configured in your operating system. Plesk only sees the IPs, but does not handle gateway addresses.