ipv4 | 【已废弃】IP v4 中国城市地址库

I've been trying to get over this but I'm out of ideas for now hence I'm posting the question here.

I'm experimenting with the Oracle Cloud Infrastructure (OCI) and I wanted to create a Kubernetes cluster which exposes some service.

The goal is:

• A running managed Kubernetes cluster (OKE)
• 2 nodes at least
• 1 service that's accessible for external parties

The infra looks the following:

• A VCN for the whole thing
• A private subnet on 10.0.1.0/24
• A public subnet on 10.0.0.0/24
• NAT gateway for the private subnet
• Internet gateway for the public subnet
• Service gateway
• The corresponding security lists for both subnets which I won't share right now unless somebody asks for it
• A containerengine K8S (OKE) cluster in the VCN with public Kubernetes API enabled
• A node pool for the K8S cluster with 2 availability domains and with 2 instances right now. The instances are ARM machines with 1 OCPU and 6GB RAM running Oracle-Linux-7.9-aarch64-2021.12.08-0 images.
• A namespace in the K8S cluster (call it staging for now)
• A deployment which refers to a custom NextJS application serving traffic on port 3000

And now it's the point where I want to expose the service running on port 3000.

I have 2 obvious choices:

• Create a LoadBalancer service in K8S which will spawn a classic Load Balancer in OCI, set up it's listener and set up the backendset referring to the 2 nodes in the cluster, plus it adjusts the subnet security lists to make sure traffic can flow
• Create a Network Load Balancer in OCI and create a NodePort on K8S and manually configure the NLB to the ~same settings as the classic Load Balancer

The first one works perfectly fine but I want to use this cluster with minimal costs so I decided to experiment with option 2, the NLB since it's way cheaper (zero cost).

Long story short, everything works and I can access the NextJS app on the IP of the NLB most of the time but sometimes I couldn't. I decided to look it up what's going on and turned out the NodePort that I exposed in the cluster isn't working how I'd imagine.

The service behind the NodePort is only accessible on the Node that's running the pod in K8S. Assume NodeA is running the service and NodeB is just there chilling. If I try to hit the service on NodeA, everything is fine. But when I try to do the same on NodeB, I don't get a response at all.

That's my problem and I couldn't figure out what could be the issue.

What I've tried so far:

• Switching from ARM machines to AMD ones - no change
• Created a bastion host in the public subnet to test which nodes are responding to requests. Turned out only the node responds that's running the pod.
• Created a regular LoadBalancer in K8S with the same config as the NodePort (in this case OCI will create a classic Load Balancer), that works perfectly
• Tried upgrading to Oracle 8.4 images for the K8S nodes, didn't fix it
• Ran the Node Doctor on the nodes, everything is fine
• Checked the logs of kube-proxy, kube-flannel, core-dns, no error
• Since the cluster consists of 2 nodes, I gave it a try and added one more node and the service was not accessible on the new node either
• Recreated the cluster from scratch

Edit: Some update. I've tried to use a DaemonSet instead of a regular Deployment for the pod to ensure that as a temporary solution, all nodes are running at least one instance of the pod and surprise. The node that was previously not responding to requests on that specific port, it still does not, even though a pod is running on it.

Edit2: Originally I was running the latest K8S version for the cluster (v1.21.5) and I tried downgrading to v1.20.11 and unfortunately the issue is still present.

Edit3: Checked if the NodePort is open on the node that's not responding and it is, at least kube-proxy is listening on it.

I've been trying to make a request to an IPv6 address using the parseRequest function from Network.HTTP.Client (https://hackage.haskell.org/package/http-client-0.7.10/docs/Network-HTTP-Client.html) package as follows:

request <- parseRequest "http://[2001:0db8:85a3:0000:0000:8a2e:0370:7334]"

Instead of parsing it as an address/addrInfo, it is parsed as a hostname and throws the error: does not exist (Name or service not known). As a next step, I tried pointing a domain to the same IPv6 address and then using the domain name in parseRequest, then it successfully resolves that into the IPv6 address and makes the request. Is there some other way I can directly use the IPv6 address to make the request using the http-client package?

PS: I also tried without square brackets around the IP address, in this case the error is Invalid URL:

request <- parseRequest "http://2001:0db8:85a3:0000:0000:8a2e:0370:7334"

More context:

For an IPv4 address, the getAddrInfo function generates the address as:

AddrInfo {addrFlags = [AI_NUMERICHOST], addrFamily = AF_INET, addrSocketType = Stream, addrProtocol = 6, addrAddress = 139.59.90.1:80, addrCanonName = Nothing}

whereas for IPv6 address(inside the square brackets format):

AddrInfo {addrFlags = [AI_ADDRCONFIG], addrFamily = AF_UNSPEC, addrSocketType = Stream, addrProtocol = 6, addrAddress = 0.0.0.0:0, addrCanonName = Nothing}

and the error prints as:

(ConnectionFailure Network.Socket.getAddrInfo (called with preferred socket type/protocol: AddrInfo {addrFlags = [AI_ADDRCONFIG], addrFamily = AF_UNSPEC, addrSocketType = Stream, addrProtocol = 6, addrAddress = 0.0.0.0:0, addrCanonName = Nothing}, host name: Just "[2001:0db8:85a3:0000:0000:8a2e:0370:7334]", service name: Just "80"): does not exist (Name or service not known))

Good morning people.

I'm trying to understand the error below but as I'm new to rails, I didn't quite understand. Does anyone have a light on what it could be?

I searched the internet but didn't find anything specific.

I searched on the internet but didn't identify anything, if anyone has seen it or has the link, you can send me and I'll see.

If you need any more information to help, let me know and I'll edit the post and add it, I don't know if there's anything else I could have already posted.

thank you for your help !!

When I try to open psql with this command:

I have a UDP sender program here:

I am working on a "heartbeat" application that pings hundreds of IP addresses every minute via a loop. The IP addresses are stored in a list of a class Machines. I have a loop that creates a Task (where MachinePingResults is basically a Tuple of an IP and online status) for each IP and calls a ping function using System.Net.NetworkInformation.

The issue I'm having is that after hours (or days) of running, one of the loops of the main program fails to finish the Tasks which is leading to a memory leak. I cannot determine why my Tasks are not finishing (if I look in the Task list during runtime after a few days of running, there are hundreds of tasks that appear as "awaiting"). Most of the time all the tasks finish and are disposed; it is just randomly that they don't finish. For example, the past 24 hours had one issue at about 12 hours in with 148 awaiting tasks that never finished. Due to the nature of not being able to see why the Ping is hanging (since it's internal to .NET), I haven't been able to replicate the issue to debug.

(It appears that the Ping call in .NET can hang and the built-in timeout fail if there is a DNS issue, which is why I built an additional timeout in)

I have a way to cancel the main loop if the pings don't return within 15 seconds using Task.Delay and a CancellationToken. Then in each Ping function I have a Delay in case the Ping call itself hangs that forces the function to complete. Also note I am only pinging IPv4; there is no IPv6 or URL.

Main Loop

Whenever I try to run

I tried to run my express app with port 5000, and I found that some processes are already using it:

In AWS EC2, I start a Classical Load Balancer in front of EC2 instance (security group of EC2 instance is launch-wizard-3). i want to change the inbound rule of Security Group of EC2 instance . A security group for Classical Load Balancer (it's name is my-first-load-balancer-sg) was also started. when i am changing source of an inbound rule of launch-wizard-3 to the my-first-load-balancer-sg, following error is prompted. I tried many times to solve it, but i couldn't.

the error- You may not specify a referenced group id for an existing IPv4 CIDR rule.

the inbound rule as follows

(type-HTTP, protocol-TCP, port rang-80, Source type- Custom, Source- my-first-load-balancer-sg(what i want to place) )

Please help me~! Thanks!