I have two network interfaces. Both interfaces have two private ip each for a total of 4. All are set to elastic ip.
I can ping only two public IP.
How can I activate 4 IP at a time?
You need to configure the secondory IPs from ec2 OS too.
From AWS Documentation:
Configuring the Operating System on Your Instance to Recognize the Secondary Private IPv4 Address
After you assign a secondary private IPv4 address to your instance,
you need to configure the operating system on your instance to
recognize the secondary private IP address.
If you are using Amazon Linux, the ec2-net-utils package can take care
of this step for you. It configures additional network interfaces that
you attach while the instance is running, refreshes secondary IPv4
addresses during DHCP lease renewal, and updates the related routing
rules. You can immediately refresh the list of interfaces by using the
command sudo service network restart and then view the up-to-date list
using ip addr li. If you require manual control over your network
configuration, you can remove the ec2-net-utils package. For more
information, see Configuring Your Network Interface Using
ec2-net-utils. If you are using another Linux distribution, see the
documentation for your Linux distribution. Search for information
about configuring additional network interfaces and secondary IPv4
addresses. If the instance has two or more interfaces on the same
subnet, search for information about using routing rules to work
around asymmetric routing. For information about configuring a Windows
instance, see Configuring a Secondary Private IP Address for Your
Windows Instance in a VPC in the Amazon EC2 User Guide for Windows
Instances
For Linux here is the post where the steps are explained:
https://bobcares.com/blog/an-easy-guide-to-setup-amazon-ec2-multiple-ips/
Related
I am configuring a High Availability load balancing based on HAProxy and Keepalived.
Everywhere I do research they talk about Virtual IP like something that fell off the sky – I mean, with little to none explanation about how to get one.
By now, I have arbitrary defined a virtual ip address in the keepalived.conf like this:
virtual_ipaddress {
10.0.0.100
}
With both Servers running keepalived, I do ip address command in the MASTER machine and it shows inet 10.0.0.100/32 scope global eth0 next to the Public IP, which I believe is correct.
When I do service keepalived stop in the MASTER machine and run ip address in the BACKUP machine, BACKUP shows inet 10.0.0.100/32 scope global eth0, IP which effectively disappeared from MASTER.
The above mentioned behavior indicates me that the config is all right.
Now, how can I publish that Virtual IP? Do I need to buy one? If my server provider (Contabo) doesn't offer the Virtual IP service, where to buy it?
My goal is to have my Front-End API requests aiming at the Virtual IP.
Thanks very much in advance for any guidance!
Server A and server B addresses are either manually configured when setting up the servers, or obtained via dhcp.
There is nothing magical about the virtual ip, other than it is not obtained in the same way.
If it is your own network, you can just pick one in the same range as for the two servers, and make sure that no new servers will use it.
Since you are talking about a provider, you will need to ask them if they provide floating ip addresses.
10.x.x.x is a private ip, so you can not publish that to the internet, but you could use it for example to fail over internal services.
I'm trying to have the dnsmasq of a server only listen to and respond to queries within a local network using their private IP addresses. All of the hosts needed are already on the /etc/host file, so all I need to do is configure the dnsmasq.conf file so that it only responds to local-only domains.
While researching, I've only found documents for "How to create a DNS/DHCP server using dnsmasq" but not much on routing to only certain IP addresses.
I've tried the instructions from this link:
https://www.linux.com/training-tutorials/dnsmasq-easy-lan-name-services/
and it put dnsmasq in a failed state.
When I used listen-address=[private ip] in the dnsmasq.conf file, I did nslookup for the servers that are supposed to be on the private network but it been showing the public ip for the server and address.
You should consult the official dnsmasq man page. In particular the local-service and localise-queries options:
--local-service
Accept DNS queries only from hosts whose address is on a local subnet, ie a subnet for which an interface exists on the server. This option only has effect if there are no --interface, --except-interface, --listen-address or --auth-server options. It is in tended to be set as a default on installation, to allow unconfigured installations to be useful but also safe from being used for DNS amplification attacks.
-y, --localise-queries
Return answers to DNS queries from /etc/hosts and --interface-name which depend on the interface over which the query was received. If a name has more than one address associated with it, and at least one of those addresses is on the same subnet as the interface to which the query was sent, then return only the address(es) on that subnet. This allows for a server to have multiple addresses in /etc/hosts corresponding to each of its interfaces, and hosts will get the correct address based on which network they are attached to. Currently this facility is limited to IPv4.
The first option local-service addresses your first concern, so that dnsmasq will only answer queries from hosts on the same subnet. The second option localise-queries will return answers with IP addresses from the same subnet if there are multiple IP addresses for a given name known to dnsmasq.
Why doesn't AWS allocate elastic IP's to all the servers being spawned? They allocate public IP by default to all the servers, which gets lost after a reboot of EC2 instances.
What's the logic behind not allowing elastic IPs automatically?
TL;DR Because Elastic IP (EIP) addresses are not needed for all/most use cases.
There is a limited supply of routable IP addresses. If every server on a public subnet received one, those IP addresses would remain allocated even when the servers were off. If the server was terminated it would be unclear if the use of that IP was concluded or is still necessary for other use. Which brings up the real reason for Elastic IP's.
An Elastic IP address is a static IPv4 address designed for dynamic cloud computing. An Elastic IP address is associated with your AWS account. With an Elastic IP address, you can mask the failure of an instance or software by rapidly remapping the address to another instance in your account. [1]
The take away from this is if you're not using EIP's for dynamic cloud computing you're probably using them incorrectly. This is a good example of a correct use case.
If you require a persistent public IP address that can be associated to and from instances as you require, use an Elastic IP address instead. For example, if you use dynamic DNS to map an existing DNS name to a new instance's public IP address, it might take up to 24 hours for the IP address to propagate through the Internet. As a result, new instances might not receive traffic while terminated instances continue to receive requests.[2]
I am unable to connect to amazon ec2 instance (public domain) form office network. It works fine outside the office network.
Looks like something is getting blocked in the network. Not sure how to figure out or which logs need to be checked to find out what exactly is getting blocked.
Error Message:
ec2-54-218-186-23.us-west-2.compute.amazonaws.com took too long to respond.
Typically, if the connection takes too long to respond, the problem is due to the Security Group assigned to the instance. Check that it is allowing Inbound access from the entire Internet (0.0.0.0/0) on your desired port (Windows RDP port 3389, SSH port 80).
Of course, opening up access to the entire Internet is not good for security, so it is better to limit it to a smaller range of IP addresses, such as your corporate network and your home IP address.
Reason
Security groups enable you to control traffic to your instance, including the kind of traffic that can reach your instance. For example, you can allow computers from only your home network to access your instance using SSH. If your instance is a web server, you can allow all IP addresses to access your instance using HTTP or HTTPS, so that external users can browse the content on your web server.
Before You Start
Decide who requires access to your instance; for example, a single host or a specific network that you trust such as your local computer's public IPv4 address. The security group editor in the Amazon EC2 console can automatically detect the public IPv4 address of your local computer for you. Alternatively, you can use the search phrase "what is my IP address" in an internet browser, or use the following service: Check IP. If you are connecting through an ISP or from behind your firewall without a static IP address, you need to find out the range of IP addresses used by client computers.
Warning
If you use 0.0.0.0/0, you enable all IPv4 addresses to access your instance using SSH. If you use ::/0, you enable all IPv6 address to access your instance. This is acceptable for a short time in a test environment, but it's unsafe for production environments. In production, you authorize only a specific IP address or range of addresses to access your instance.
THE SOLUTION BEGINS HERE
Your default security groups and newly created security groups include default rules that do not enable you to access your instance from the Internet. To enable network access to your instance, you must allow inbound traffic to your instance. To open a port for inbound traffic, add a rule to a security group that you associated with your instance when you launched it.
Adding a Rule for Inbound SSH Traffic to a Linux Instance
In the navigation pane of the Amazon EC2 console, choose Instances. Select your instance and look at the Description tab; Security groups lists the security groups that are associated with the instance. Choose view rules to display a list of the rules that are in effect for the instance.
In the navigation pane, choose Security Groups. Select one of the security groups associated with your instance.
In the details pane, on the Inbound tab, choose Edit. In the dialog, choose Add Rule, and then choose SSH from the Type list.
In the Source field, choose My IP to automatically populate the field with the public IPv4 address of your local computer. Alternatively, choose Custom and specify the public IPv4 address of your computer or network in CIDR notation. For example, if your IPv4 address is 203.0.113.25, specify 203.0.113.25/32 to list this single IPv4 address in CIDR notation. If your company allocates addresses from a range, specify the entire range, such as 203.0.113.0/24.
Choose Save.
You can find detailed solution here
I've just begun the setup of proxmox for our none profit educational VPS service. However, the problem we're facing is a lack of IPv4 addresses available to us.
Is it possible to route a sub-domain to the host servers IP address and then get that forwarded to the individual containers accordingly. For example:
SSH root#node-123.w-a-s-d.me
Will allow a client with the VM ID of 123 to access their server
And the same goes for things like: node-123.w-a-s-d.me
This would be the web address allowing any applications running on port 80 for that specific node
I'm unsure how to go about this and have looked online with no luck. I hope our goal is clear. I look forward to hearing from you. Josh
Exposing SSH that way will not be easy as you can only have one thing listening on port 22 for every given IP address, and while you could just adding random ports to each VPS and the forward it from primary box which holds public IP (and vms are behind nat) this is not exactly the best solution.
What you may want to do instead is set up one public-facing box that people can ssh into via public IP and from it SSH to subsequent private machines by their internal IP. Alternatively you can set that box with openVPN and set it to assign internal IP address to anyone connecting via it. While openVPN takes more time to set up right, it can come with it's own DNS so when connected to it calling out SSH root#node-123.w-a-s-d.me will automatically route you to the private IP address rather than the shared public facing one.
With HTTP this is much easier as you can set up a proxy on the front-facing machines which then proxies requests for given sub domain to specific internal IP address.