Lon-b IP address changes (deadline 9th September 2016)

Background

We know that there have been a number of issues with reliability at our London Maidenhead (lon-b) location over the last few years, many due to the C4L network. We apologise for any inconvenience caused.

We also have good news: we plan to migrate lon-b into our own Slough data centre and network. The planned date is the end of August, and we will also upgrade to new and faster hardware, including SSD-only storage, in the process.

Are your servers ready to move to Slough?

Please check your server's IP addresses. You can see them on the control panel:

Also check what IPs have been assigned as 'Primary' and 'Secondary' connections at the bottom of the control panel.

Do any of your server's static IP addresses ('Primary' and 'Secondary') start with?

  • 109.104.101.
  • 84.45.109.
  • 84.45.121.
  • 84.45.72.
  • 84.45.8.

Yes

We can't migrate all of your IP addresses to Slough. Please follow the below guide to change them.

No

All your IP addresses will be migrated to Slough without a problem.

Guide Overview:

We have already given you an extra Duplicate IPs for Reconfiguration billing plan, with free capacity to add the same number of extra IPs into your account. You need to take the following steps to prepare for the migration:

  1. Add the new IP(s) to your account
  2. Assign the new IP(s) to your running servers
  3. Configure the secondary IP address(es) in the OS
  4. Check your applications on both the old and new IP addresses
  5. Update your domains' DNS records
  6. Swap completely onto the new IP(s)
  7. Delete non-migratable IP(s) starting with 109.104.101.x 84.45.109.x 84.45.121.x 84.45.72.x 84.45.8.x


1. Add new IPs to your account

Click on Add, then select Static IP.

This will add an IP which will be available once the underlying hosts have been moved to Slough.

2. Assign new IPs to running servers

Click on your running server's "cog" symbol:

Within the network section, flag the newly added IP/s:

Scroll up, and click Save followed by Back to account overview.

The above process will allow the server to use this IP. We still need to make changes within the server's operating system to use this IP.

3. Configure the secondary IP address(es) in the OS:


Windows Servers

Gain access to your server via VNC, using the (human eye) symbol on the control panel. A VNC connection will allow us to configure the network interfaces even when the connection is down.

Start an Administrator DOS prompt:

Press the Windows key on the keyboard, then press r, type cmd and finally press Ctrl+Shift + Enter.

Type netsh interface ip show config >> Network-details.txt & notepad Network-details.txt and press Enter. This will save the current network settings to a file called Network-details.txt and open it in Notepad:

Within the Network-details.txt file check if DHCP is enabled for the Local Area Network. If yes, we will now convert this IP into a static value so we can assign multiple static addresses.

If your IP is static then please proceed to Configure a Secondary Public IP Address for Your Windows VM.

Convert to static IP

Keeping the notepad file open for reference, launch the Network and Sharing Center by running the following command from the Administrator DOS prompt:

%SystemRoot%\system32\control.exe ncpa.cpl

Open the context menu (right-click) for the network interface (Local Area Connection) and choose Properties.

Choose Internet Protocol Version 4 (TCP/IPv4), then click on Properties. In the dialog box, choose Use the following IP address, enter the following values (from Network-details.txt):

  • IP Address
  • Subnet
  • DNS servers

When you're done, click OK.

To add additional DNS servers, use the Advanced button, choose the DNS tab and click on Add. Your server retains the same IP address information as before, but now this information is static and not managed by DHCP.

Configure a Secondary Public IP Address for Your Windows VM

Within the Network and Sharing Center open the context menu (right-click) for the network interface (Local Area Connection) and choose Properties.
Choose Internet Protocol Version 4 (TCP/IPv4), Properties, then Advanced and click on Add.

In the TCP/IP Address dialog box, enter the new IP/s from the ElasticHosts control panel. Use 255.255.255.0 as the Subnet mask, and then choose Add. On the same page, add a Gateway for the new public IP address, it will be the same as the IP, except the last digit will be .1.

Verify the IP address settings; if everything is okay, click OK twice, and then Close.

To confirm the above changes, at the command prompt, run the command: netsh interface ip show config >> Network-details2.txt & notepad Network-details2.txt

Within the Network-details2.txt file, we should now see the new configuration.

Sometimes you might need to right click and Disable/Enable the Local Area Connection to refresh the network settings. Test if you can ping your existing and new IP/s from your workstation.

Linux Servers

Gain access to your server using SSH. The username might be toor and the password might be visible on the server:

Save the current network settings to a file called Network-details.txt via the below command:

/sbin/ifconfig -a >> Network-details.txt

Output the routing, to the same file, via the below command:

route -n >> Network-details.txt

Check you don't already have an IP on eth0:1 by running the below command:

/sbin/ifconfig -a | grep 'eth0:1'

This should return nothing. If it does, keep grepping with eth0:2, eth0:3, etc. until you find a free interface. Please use this value instead of eth0:1 in the below commands.

We'll now temporarily add new IP/s and route/s to the server via the below commands, replace 5.152.176.71 with the IP you added earlier:

ip addr add 5.152.176.71/24 dev eth0 label eth0:1

route add -net 5.152.176.0/24 gw 5.152.176.1

In the above example commands, the new IP is 5.152.176.71 and the gateway is the same as the IP, except it always ends with .1. Test you can ping your existing and new IPs from your local workstation.

Confirm the above addition via the below command:

/sbin/ifconfig -a

4. Check your applications on both the old and new IP addresses

Check your application, for example web server, to see if it responds on the new and old IP address. Your application settings might need altering to communicate on the new IP.

5. Update your domains' DNS records

Update your domains' DNS records, using the new IP, and wait until they have propagated globally. Note, complete DNS resolution may take up to 48 hours. Use an online DNS propagation checker to monitor the progress. Search for 'check dns propagation'.

6. Swap completely onto the new IP(s)


Windows servers

If your server was previously using DHCP, visible in the Network-details.txt file as DHCP enabled: Yes. Follow the below steps:

Open the Network and Sharing Center:

Press the Windows key on the keyboard, press r, type cmd and press Ctrl+Shift + Enter. Type %SystemRoot%\system32\control.exe ncpa.cpl, and press Enter.

Open the context menu (right-click) for the network interface (Local Area Connection), and choose Properties. Select TCP/IPv4 and then Properties, set Obtain an IP address automatically followed by OK and Close.

If you previously had a number of static IP addresses set, visible in the Network-details.txt file.
Set the server's new primary and secondary IP/s using the methods already covered, remember to remove the 109.104.101.x , 84.45.109.x , 84.45.121.x , 84.45.72.x , 84.45.8.x addresses.

Now, shut down your server.

Linux servers

Check if you had any IP information hard-coded in your configuration files with the below commands:

RHEL/CentOS/Fedora
grep '84.45\|109.104' /etc/sysconfig/network-scripts/ifcfg-eth0

Ubuntu/Debian/Linux Mint
grep '84.45\|109.104' /etc/network/interfaces

If the command returns nothing, please skip to Both Linux and Windows

Replace the old IP information in your distributions eth0 network configuration file (listed below), using your favourite editor: nano,vim...

All new lon-b gateways end in .1.

Adjust the IP/s, Subnet mask (255.255.255.0) and Gateway/s.

RHEL/CentOS/Fedora
Uses /etc/sysconfig/network-scripts/ifcfg-eth0

Ubuntu/Debian/Linux Mint
Uses /etc/network/interfaces

It's advisable to make a copy of these files before editing them, using the below command:

RHEL/CentOS/Fedora
cp -i /etc/sysconfig/network-scripts/ifcfg-eth0{,.EHbackup}

Ubuntu/Debian/Linux Mint
cp -i /etc/network/interfaces{,.EHbackup}

Shutdown your server once complete.

Both Linux and Windows

Please ensure your server is powered off.

On the ElasticHosts' control panel click on the server's cog symbol and now set the new IP as the default via DHCP:

Scroll up, and click Save followed by Back to account overview.

Power your server back on again.

7. Final step

Finish off the process by deleting the existing IPs 109.104.101.x 84.45.109.x 84.45.121.x 84.45.72.x 84.45.8.x from your Elastichosts control panel.


Help

If you have any questions, please do not hesitate to contact our support team by clicking on the support link in the top right of the control panel, or using direct email.