Cannot SSH to Amazon EC2 instance from ubuntu 14.04 LTS - amazon-web-services

I followed everything in exact same order as refered here :Amazon Set Up Documentation. I also read many SO answers but everyone suggested on checking the security group and route tables. I did everything none of them helped.
I have a USB Dongle which I use to surf internet. Its IP changes everytime I disconnect the dongle and reconnect it. But if I stay connected its IP remains same. So I did created a security group my_ip/32 and launched an ec2 instance. So without disconnecting my dongle i.e keeping my IP intact I tried to connect to the instance through SSH with simple
ssh -v -i my-key-pair.pem user#public_dns
command but with no luck.
But the funny thing is I can connect to the ec2 instance if I change my security group to 0.0.0.0/0 which is not suggested by amazon because of security issue.
Does anybody has faced the similar situation. Or Amazon did miss something in their documentation.
NOTE:
I also enable firewall in ubuntu for ssh as follows:
sudo ufw allow ssh/tcp
sudo ufw enable
Am I missing something??

When you google 'what is my ip' does it give you the result you expected for my_ip? Google will report back the IP the outside world sees you as.
I have a feeling you might be going through a NAT router which you're recieving DHCP from, as such you're dongles IP isn't even being seen by EC2 to match a security group.

Related

Can't reach to an AWS EC2 instance website

I just launched a instance on AWS and I'm trying to open the website. So I copy the Public IPv4 address and paste it on my page. But it always returns This site can’t be reached 35.78.183.239 took too long to respond.
I've changed my firewall setting to access google chrome and set security groups HTTP, HTTPS. I can't figure out where the problem is. Any suggestions?
You didn't specify what webserver or AMI is on your EC2 instance.
You need to setup an AMI or manually install and setup a webserver for anything to show, otherwise the EC2 instance, while reachable, will not respond.
Make sure that ssh access is enabled and try ssh into the machine. If you can successfully login, then you know the instance is reachable and the problem is with your webserver software. This will help you debug.
What port is your application running on? When you enable HTTP and HTTPS it only allows ports 80 and 443 on the security group. This won't help if your application runs on a different port, so you'll need to add that to your security group to allow inbound traffic.

Can't connect to one EC2 instance in the same security group of another accessible EC2 instance

I have two EC2 instances running Windows. They are both in the same security group which allows for all outgoing ports, but only RDP ports from my IP. What I can't figure out is that both, to my examination, have the same security and networking settings, but one connects through RDP but the other one doesn't.
Any suggestions for settings to look at?
After a few attempts of download the .rdp file, checking the inbound rules, running nslookup myip.opendns.com resolver1.opendns.com to see my IP just to make sure I wasn't going crazy.
Ultimately what solved the problem was restarting my own computer and running the .rdp file. Not sure why, but maybe my computer was sending stale configuration data.

EC2 is not responding for ssh connection

Another bad day. I have all the configuration for my ec2 instance.
Till yesterday I was able to connect it via ssh on mac. but know why it's not getting connect now.
Configuration is as below:
Security Group:-
I'm using below steps as usual and I'm same directory where mypleaks-inst.pem kept.
My guess: Your security group that was applied was "launch-wizard-2" which by default sets exlusion rules. You need to associate that EC2 instance with one of the two security groups listed in your second screen shot to allow TCP connections on port 22 from inbound ip range. OR you could modify launch-wizard-2 to incorporate the relevant rules to allow for ssh connection.
if you're sure nothing was changed on AWS side then perhaps your SSH service is down temporarily or permanently (the server was overloaded? You can do it with ease with T2.small).
Check NACL and routing, otherwise.

Cannot connect to EC2 - ssh: connect to host port 22: Connection refused

I am currently overseas and I am trying to connect to my EC2 instance through ssh but I am getting the error ssh: connect to host ec2-34-207-64-42.compute-1.amazonaws.com port 22: Connection refused
I turned on my vpn to New York but still nothing changes. What reasons could there be for not being able to connect to this instance?
The instance is still running and serving the website but I am not able to connect through ssh. Is this a problem with the wifi where I am staying or with the instance itself?
My debugging steps to EC2 connection time out
Double check the security group access for port 22
Make sure you have your current IP on there and update to be sure it hasn't changed
Make sure the key pair you're attempting to use corresponds to the one attached to your EC2
Make sure your key pair on your local machine is chmod'ed correctly. I believe it's chmod 600 keypair.pem check this
Make sure you're in either your .ssh folder on your host OR correctly referencing it: HOME/.ssh/key.pem
Last weird totally wishy washy checks:
reboot instance
assign elastic IP and access that
switch from using the IP to Public DNS
add a : at the end of user#ip:
Totally mystical debugging sets for 6 though. That's part of the "my code doesn't work - don't know why. My code does work - don't know why." Category
Note:
If you access your EC2 while you are connected to a VPN, do know that your IP changes! So enable incoming traffic from your VPN's IP on your EC2 security group.
In AWS, navigate to Services > EC2.
Under Resources, select Running Instances.
Highlight your instance and click Connect.
In Terminal, cd into the directory containing your key and copy the command in step 3 under "To access your instance."
In Terminal, run: ssh -vvv -i [MyEC2Key].pem ec2-user#xx.xx.xx.xx(xx.xx.xx.xx = your EC2 Public IP) OR run the command in the example under step 4.
Just check if your public ip that you get when you are on VPN is configured as a source address in the SG inbound entry that opens up port 22.
You can check your ip using https://www.google.co.in/search?q=whats+my+ip, when connected to your VPN.
I tried everything in this and several other answers, also in some aws youtube videos. Lost perhaps five hours over a few sessions trying to solve it and now finally..
I was getting the exact same error message as the OP. I even rented another EC2 instance in a nearer data centre for twenty minutes to see if that was it.
Then I thought it might be the router or internet provider in the guest house where I am staying. Had already noticed that some non-mainstream news sites had been blocked - and that was it!
You can check if the router is blocking port 22:
https://superuser.com/questions/1336054/how-to-detect-if-a-network-is-blocking-outgoing-ports
cardamom#neptune $ time nmap -p 22 portquiz.net
Starting Nmap 7.70 ( https://nmap.org ) at 2021-02-03 20:43 CET
Nmap scan report for portquiz.net (27.39.379.385)
Host is up (0.028s latency).
rDNS record for 27.39.379.385: ec2-27-39-379-385.eu-west-3.compute.amazonaws.com
PORT STATE SERVICE
22/tcp closed ssh
Nmap done: 1 IP address (1 host up) scanned in 0.19 seconds
real 0m0,212s
user 0m0,034s
sys 0m0,017s
Then, the question of why someone would want to block the ssh port 22 is addressed in at length here:
https://serverfault.com/questions/25545/why-block-port-22-outbound
Had the same problem after creating some instances on a new VPC. (If internet SSH worked before this solution may not work for you)
When creating a new VPC, make sure you create an internet gateway (VPC -> Internet Gateways)
And also make sure that your VPC's routing table (VPC -> Route Tables) has an entry which redirects all IPs (or just your IP) to the internet gateway you just created.
For me, it was because of this:
NOT ec2-user#xx.xx.xx.xx
BUT THIS =>>> ubuntu#xx.xx.xx.xx
Watch the image of EC2 instance!
Instead of
ssh -i "key.pem" ubuntu#ec2-161-smth.com
use
ssh -i "key.pem" ec2-user#ec2-161-smth.com

AWS: Cannot connect to Amazon instance

I had been trying to establish a MongoDB database with an exposed REST API (through Crest, then Sleepy Mongoose), but neither of these had been working. I tried to do a minimal sanity test of "Can I connect to that AWS machine or not?", so here's what I tried:
1) I set up a new Amazon instance (Ubuntu 14.04), and I made sure that all incoming TCP connections were accepted.
2) I tried running sudo python -m SimpleHTTPServer 80.
3) This worked when logged into the machine and doing curl http://localhost:80/ and curl http://XX.XX.XX.XX:80/ (the machine's IP address substituted of course). However, on my local machine, the command just timed out.
I'm really looking forward to any guidance here, so I can hopefully go back to what I was originally doing (MongoDB, exposing a REST API, etc.). Really thankful for any suggestions since this has been driving me crazy!!
This is probably a security group issue.
When doing the curl http://XX.XX.XX.XX:80/ on the machine itself, did you try the internal ip (172.x.x.x / 10.x.x.x / 192.x.x.x) or the external ip?
Also, does the machine have an external ip assigned? (I'm guessing it does, otherwise ssh'ing to it would only be possible from another machine in the same subnet.)
Go to the AWS console, open the instance details and check the instance's security groups. Is port 80 open for the world (0.0.0.0/0) ?