I have successfully assigned an IPv6 block to my VCN. When I try to assign a block to my subnet within the same VCN, it asks me to choose an IPV6 CIDR block.
The IPv6 assigned to my VCN: 2603:c020:4002:6c00::/56
I am trying to assign the following to my subnet:
2603:c020:4002:6c91::/64
The GUI lets me edit only the '91' part in there, as demonstrated above.
When I confirm the change, it fails with an error (image attached). I have tried destroying the resources and recreating the VCN, subnet, etc., for troubleshooting. IPv4 works fine, and I can create resources without any hiccups.
Is that a bug in OCI? I have been assigned 2603:c020:4002:6c00::/56 to my VCN. I cannot use 2603:c020:4002:6c91::/64 in my subnet because it belongs to 2603:c020:4002:6c91::/56. I can use 2603:c020:4002:6c00:91::/64 in my subnet. But then, Oracle is not letting me do this and giving me the error "NotAuthorizedOrNotFound". The error is inevitable as 2603:c020:4002:6c91::/64 does not belong to my VCN.
I may be wrong here; my IPv6 skills are not top-notch.
In any case, please help. I am a free tier subscriber and cannot raise a ticket directly.
I used a wizard to create the VCN. The wizard is not IPv6 aware, and I assigned an IPv6 manually to it later via the web GUI. The same wizard creates two subnets - one public and one private. I was trying to attach an IPv6 range to those subnets. But it was giving me an error. I created a new subnet in the VCN and was able to assign IPv6 to that subnet.
The solution was - manually create a new subnet in the VCN and add IPv6 to it.
Related
I am trying to set up SSM on Windows.
I have an ASG in a private subnet (absolutely 0 internet access). I can not use NAT, only VPC endpoints.
In the instance launch configuration, I have a PowerShell script that uses Set-DnsClientServerAddress so that the instance can find and join an AWS Managed MS AD service. I would also like to set up the instance so it can be fully managed with SSM.
The problem comes with the DNS Client Server Address.
When I set it to match the address of the AD service SSM will not work.
When I leave the DNS Client Server Address default, SSM works but I can not join the AD.
I tried forcing the SSM Agent to use the endpoints by creating a amazon-ssm-agent.json file and setting all three endpoints in there. This allowed the instance to show on the Managed Instance list, but its status never changed from pending and requests from within the instance still timed out.
Does anyone know the magic sauce to get these things all working at the same time?
EDIT 1:
I also tried adding a forward as described in this thread, however I'm either missing somethign or it is not working for my case:
https://forums.aws.amazon.com/thread.jspa?messageID=919331󠜣
It turns out that adding the forwarder as described in the link above worked. The part I was missing was joedaws comment, "I would also remove the existing 169.254.169.253 entry so that only the 10.201.0.2 ip address is in the list".
Of course, my IPs are different, but once I removed the preexisting forward so that my x.x.x.2 IP was the only one in the list (I did this for both of the AD DNS servers) the instance was discoverable by SSM.
So, I would make a minor change to the list that saugy wrote:
On a domain joined windows instance, log in with AD domain Admin user
Open DNS manager
Connect to one of the DNS IP addresses for the AWS AD
Select forwarders
Add the VPC's DNS IP (x.x.x.2 from you VPC's CIDR range)
Remove the existing IP (so you VPCs IP is the only one)
Click Apply
Repeat from step 3 with the other DNS IP address for the AWS AD (not 1
Also, as mentioned in the other post. This only has to be done once and the settings persist in the AD DNS.
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.
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
For testing purposes, I set up a VPC on Amazon and created an instance within the VPC. I've added a gateway for the 0.0.0.0/0 address to the attached routing table, and given the instance an elastic IP address. I'm unable to ssh or ping it, even when I set the security group to allow all traffic. I must be missing something obvious. What am I doing wrong?
It turns out that when I created the instance, I accepted the default security group, which only allows access from a specific IP address. When I added another instance, I created it with a security group which allowed all traffic, and I was able to ping it.
This is probably incredibly simple and I'm just missing one step. The problem I was (originally) trying to solve was how to get a statically allocated hostname, one that would not change with each restart. I've done the following steps:
I have a domain registered on GoDaddy, and it points to my EIP. I use it to connect over SSH (putty) to my EC2 instance, so I know that part is working. I've opened ports 9080, 9060, 9043, and 9443 as well as SSH and FTP ports. And I've installed and started the software that uses those ports, and that stuff normally just works on a local RHEL install, so I think what's different here is the custom domain name.
I've added my EIP and fully qualified host name to my /etc/hosts file.
I've added my fully qualified host name to my /etc/hostname file and modified the /etc/rc.local script to set the hostname properly on a restart, and that works. If I execute the command hostname, it returns my fully qualified hostname, so that looks ok.
I cannot ping my server, but I think that's ok, because probably amazon blocks pings. So I don't think that's a symptom of anything.
I cannot open a to http://myserver.mydomain:9080/, which normally just works. Here it just times out.
If I do a wget http://myserver.mydomain:9080 from inside the EC2 instance, it returns failed: No Route To Host
But if I do a wget against localhost instead of the fully qualified name I get what I expect as a response.
So.... routing tables? Do those need to change? And if so how?
You probably don't want to do what you did. Everything in EC2 is NAT'd. Meaning that the IP assigned to your instance is a private/internal ip and the public IP is mapped to it by the routing system.
So internally, you want everything to resolve to the private IP, or you will get charged for traffic as it has to get routed to the edge and then route back in. Using the public DNS name will resolve correctly from the default DNS servers.
If you are using RHEL, you will need to make sure both the security group and the internal firewall (iptables) have ports opened. You could just disable the internal firewall since its a bit redundant with the security groups. On the other hand, it can provide some options security groups do not if you need them.