Support for multiple network interfaces (overcoming AWS private IP addresses limit)

ivan.g

Member
Mar 5, 2008
9
2
53
Setting up cPanel/WHM 11.40.x in AWS and apparently AWS has limit of 15 private IP addresses per interface for the instance type we used.

The server has to support around 40 SSL certificates (so we need around 40 IPs) and thus I am having problem resolving this 15 IP addresses (per interface per instance) limit issue.

Does any one knows how to setup cPanel to use 2,3 or 4 interfaces and use same private IP range, say if we split one /24 IP range giving 15 IP addresses per interface (total IPs used 60 out of the /24 IP range).
Example:
eth0: 10.0.0.2 - 10.0.0.17
eth1: 10.0.0.18-10.0.0.33
and so on

Another possible solution to setup interface bonding like in this article:
/http://www.24x7servermanagement.com/blog/binding-multiple-network-interfaces-nic-into-single-interface/

in mode 3 (broadcast).

Is use of multiple network interfaces supported by cPanel? What other options I may be missing to resolve this IP limit per interface?
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,880
2,270
463
The URL should now load well.

Thank you.
 

jndawson

Well-Known Member
Aug 27, 2014
350
39
78
Western US
cPanel Access Level
DataCenter Provider
Michael,

The URL should now load well.

Thank you.
The URL loaded, and the one big surprise is that cPanel can't see more than one nic for public use. Here's the issue:


We had one IP (the license IP) on eth0 (new box that we've brought up. After lots of testing, want to add a /27). We were having some routing issues, and the network guys said that IP is on a subnet behind an old fire wall that has been starting to show its age. A new nic (eth1) was added and a /27 subnet (different one than the original IP is in) was made available.

We added the IPs to eth1 with the intention of turning up the nic, testing, then getting the license moved to the new IP.

Ha! Best laid plans and all that.

Once eth1 was turned up, cpanel couldn't function - no whm, no cpanel, no mail, no nothing. So I logged in via ssh to the new IP, checked that eth0 was still up, but couldn't route to it, ping it or anything else. Did everything I know how to do. Then turned off eth1, restarted, and back to the beginning.

How do we renumber onto another nic without breaking things? Ancillary question: why can not cpanel use more than one nic?
 
Last edited:

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,880
2,270
463
Hello,

You may find this thread helpful:

https://www.centos.org/forums/viewtopic.php?t=24665

However, it's really a better idea to have your data center modify this configuration for you, as you could lose access to the server if you make a mistake doing it yourself. I suggest opening a feature requests for native support of more than one NIC if it's something you would like to see implemented in the product:

Submit A Feature Request

Thank you.
 

jndawson

Well-Known Member
Aug 27, 2014
350
39
78
Western US
cPanel Access Level
DataCenter Provider
Hello,

You may find this thread helpful:

https://www.centos.org/forums/viewtopic.php?t=24665

However, it's really a better idea to have your data center modify this configuration for you, as you could lose access to the server if you make a mistake doing it yourself. I suggest opening a feature requests for native support of more than one NIC if it's something you would like to see implemented in the product:

Submit A Feature Request

Thank you.
That's a nice tutorial for renaming nics, which doesn't help us retire the IP address that cpanel is licensed under and assign it to a new IP without causing whm and cpanel to stop functioning.

Let me restate the question, keeping in mind that we are the data center:

We have one (1) IP assigned to a new cp box on eth0. That IP is the licensed IP. That IP and the nic is in a subnet (a /23, actually) that is getting moved to another part of the network as part of an equipment upgrade and system realignment. That IP will not be available on this new cp box, so another subnet has been made available to another nic (eth1), which is routed differently than eth0. We need to change IPs and put them on the new nic. The first two attempts resulted in eth0 not routing and no access to whm/cpanel, apparently due to the fact the IP address used for the license is on there and cpanel can't handle more than one nic at a time (really? still?).

So, we need to get a new IP assigned to the license and swap it to another subnet on another nic without losing any uptime.

How does one do that?
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,880
2,270
463
As far as licensing, you can update the IP address that's licensed for cPanel through the Manage2 interface (if you are a cPanel Partner), by contacting cs[@]cpanel.net via email, or by opening a support ticket using the link in my signature. The network configuration change is not manageable through the cPanel/WHM software (though you can modify the ETHDEV value in /etc/wwwacct.conf).

Thank you.
 
Last edited:

jndawson

Well-Known Member
Aug 27, 2014
350
39
78
Western US
cPanel Access Level
DataCenter Provider
As far as licensing, you can update the IP address that's licensed for cPanel through the Manage2 interface or by contacting cs[@]cpanel.net. The network configuration change is not manageable through the cPanel/WHM software (though you can modify the ETHDEV value in /etc/wwwacct.conf).

Thank you.
No, you can't. Manage2 doesn't exist. See Support Request Id 6271753.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,880
2,270
463
Thanks, I've updated my post to reflect that information. I see that our customer service team is now handling your license questions.