Basic Networking

How can I send email from my servers? Can you lift the SMTP (port 25) block?

We are happy to lift the SMTP block so you can send email from your servers. Please email to request this, confirming that:

  • any mailing lists you run on the servers are strictly opt-in, and
  • all messages sent to those mailing lists contain instructions on how to unsubscribe.

How can I track my bandwidth use?

A report of received, transmitted and total bandwidth for your account is shown on your billing page, with links to display traffic graphs. You can edit the URL parameters on these graphs to adjust the timeframe and offset: window = graph time duration in seconds offset = graph end distance before now in seconds width and height in pixels Per-server traffic graphs are available from the control panel. There is a link next to the VNC IP address when the server is running.

What internet bandwidth can I expect? Is this limited?

In each of our availability zones, your virtual machines are connected directly to a major ISP’s backbone network at 1Gbps speed. We do not cap or throttle the connection.

What is the difference between the virtual network cards you offer? Which do you recommend?

By default, your VM will use the Intel PRO/1000 emulated NIC, as it is the most modern and is widely supported in modern operating systems. However, wider support for the Realtek RTL8139 card means that we recommend using the Realtek emulation if you experience any problems with the Intel model: Windows XP/2003 users in particular may find that the older card is better supported on their OS.

What happens if I go over my subscribed bandwidth limit?

If you go over your subscribed bandwidth limit, then you will be charged the hourly burst rate for additional bandwidth and this will be deducted automatically from your prepay balance. When your prepay balance runs out there is a buffer of 10-20 GB which you can use. After that your servers will be automatically shut down. As your prepay balance is being used up, you will receive warning emails, letting you know you should top up (or increase your subscriptions).

Will I be charged for bandwidth between my servers?

Yes, we charge for all bandwidth usage that does not go over a private VLAN.

Do you block any network traffic?

We block outbound connections to SMTP, FTP, SSH and telnet servers to prevent abuse of our trials for sending spam or conducting dictionary attacks against other internet hosts. Port 5900 is used for running the VNC console.

My VM won’t connect to the internet – what can I do?

If you can’t connect to the internet, you can still connect to the VM using the provided VNC server. This allows you to ensure that everything is running normally, and fix any configuration issues which may be affecting the network connection. RHEL or CentOS users may find that they are affected by this known bug within their OS.


What is a private VLAN and why would I use it?

A VLAN acts like a private gigabit ethernet switch connecting your servers together via a second virtual ethernet card in each server. This network is isolated from the internet and other customers. Bandwidth over a VLAN is not chargeable.

How can I configure a private VLAN?

First, purchase a private VLAN subscription. Then add it to your account in the control panel. Then, edit each server’s configuration to use your private VLAN. This is under the Advanced settings.

Do private VLANs work between your availability zones?

No. A private VLAN can only be set up within a single availability zone, so any traffic sent between our different availability zones will be charged at the standard rates.

IP address

How do I set reverse DNS for my static IP addresses?

You can set this on the control panel – simply add your desired reverse domain name into the box by the IP, and click the ‘Submit’ button.

How do I use multiple static IPs on the same server?

You will need to configure this inside your server. The networking option on the server configuration page just sets the IP address that the server is supplied by DHCP and uses for VNC. This should be the ‘primary’ IP of the server, but you can also use any other static IPs in your account if you configure these inside your server operating system.

How do I remove a static IP address from my account?

Since all the static IP addresses in your account are available to be used by all servers at any time, then you will need to stop your servers before you will be able to delete a static IP address from your account.

How do I get a static IP address?

Servers are configured with a dynamic IP by default, but you can purchase a subscription for as many static IP addresses as you need through the subscriptions page in your account. You then need to allocate the actual addresses by clicking ‘add static IP’ on the control panel, and configure the static IP in your server configuration.

Load balancing / Clustering

How do I set up load balancing between my servers? Which tools do you recommend?

We recommend that you set up a small server in your cluster, running a load balancer, such as HAProxy or Pound, and connect it to your backend web servers over a VLAN.

How can I configure my system to fail over between your two clusters?

The easiest way of configuring failover is to use a DNS-based failover method. Set a low TTL on the A record for your website to avoid excessively long caching, and alter this to point to the backup server when the production server is down. There are third-party DNS providers who offer this kind of service as part of their DNS hosting offering.


How do I set up a firewall on my servers?

You can purchase a firewall for your server (for charges, see the Pricing page). To add a firewall to your server, from the ElasticHosts control panel, first shut down the server, then click Edit. On the Edit page, click “Enabled” next to Firewall: don’t forget to hover your mouse over the green tooltip for more information on the options available to you here.

What access do ElasticHosts staff have to my servers?

Elastichosts staff do not have access to your server passwords. The only access they have is the ability to see the VNC display, which they may use from time to time to check that your server is running.

How can I encrypt VNC connections to a server?

We do support TLS VNC using the VeNCrypt extensions, which some VNC clients support. You can enable this option through the advanced settings in the server configuration page. Note there are several different incompatible schemes for TLS on VNC. gtk-vnc/vinagre on Linux is a popular client that works with VeNCrypt.

How can I disable VNC on a server?

On the server configuration page, you can disable VNC access by leaving the VNC password field blank.