I recently signed up for OCI Free Tier, but I can't seem to access the internet from within the instance. What should I do?
This problem occurred after the apt-get update command and although it finds the ubuntu mirror server ( archive.ubuntu.com:80 )
Doesn't rise above 0%
I also tried the ping command, but it says that even if I find the server address, it is 100% lost.
I'm a new developer and I'm not sure how to deal with this.
I opened the port 80,443 of the firewall and updated VNC and assigned a fixed address.
Same phenomenon repeated
I couldn't check the arp command because there is no net-tools package, but judging from the mirror server or ping command, the internet connection looks up the DNS server, but it doesn't seem to upload/download.
Related
I make a connection for connect to the Database Server (other machine).
Then I found "An error was encountered performing the requested operation:
IO Error: The Network Adapter could not establish the connection
Vendor code 17002".
Please look the picture in URL below.
I tried to make a connection but can't access but my team can access it.
My friend used TNS connection type and I did everthing similar him but can't access. I tried to use JDBC thin for connect but can't also.
I had the old connection which I can connect but why I can't connect the new connection.
You're trying to connect to a machine on a network that SQL Developer is unable to reach.
For a TNS connection,
Look at the appropriate TNSNames entry (you will have a tnsnames.ora) file, and find the IP address or network name associated with the connection you're trying to establish -
And then start by trying to ping that resource.
In this case, i'm trying to talk to a database on MY machine, on port 1521. Yours should look quite different.
If you're using a basic connection, then you can look at the connection properties and see what machine/port you're trying to communicate with.
Ping
If you can't reach that machine from your machine, there's zero chance you can connect to a database there.
So, always start with a ping.
Once you see that you can get to that machine, if you're still getting that message, the next thing to think about is blocked ports, the listener defaults to port 1521, but you'll see that in the TNS descriptor as well.
It usually happens when a another process is running on the same port or there is an absence of listener.
Go to Run>services.msc>OracleXETNSListener>Start
Try to reconnect.. Even if the error still prevail then go to cmd
Use code:
npx kill-port <portnumber>
The port number by default is 1521, but you can check the port number in database properties.
It is possible, that your connection is forbidden by the firewall -
go to Control Panel\System and Security\Windows Defender Firewall - Advanced - Outbound Rules - Add a rule. (If you have some antivirus firewall, add rules there)
Create a temporary TCP rule for your port and another rule for UDP. Allow all nets and comps.
Check the telnet connection as cmd -> telnet ->
open remote.host.address PortNumber
If you can connect now, then the problem IS in firewall - edit your new rules, setting the hosts and nets exactly.
This error is because your sqldeveloper is not able to reach the database server's sql service.
One reason could be lsnrctl is down for some reason.
If you have access to machine where database is installed.
In Windows machine, follow: https://www.youtube.com/watch?v=r9pHqOfV2f0&ab_channel=TLinaTutorials
In Linux/macOS machine: Go to $ORACLE_HOME/bin and check status of lsnrctl
execute from $ORACLE_HOME/bin lsnrctl status, if it's down. Then restart it by lsnrctl start.
Check the details of connection in command output like SID, PORT, HOST etc. and try connecting again from sqldeveloper.
I am trying to connect into an EC2 instance (i am using a mac) which has a Security Group allowing all inbound traffic over ssh (port 22) but i'm unable to access. I'm having a little delay before getting an Operation timed out.
I already tried it over other devices such a raspberry pi and another macbook and the connection was successful.
I got access to the raspberry pi over ssh and tried the connection to my EC2 from the terminal; thought my ssh client or the port status could be the issue but after doing this i'm not really sure if this is the case.
This is the message i get when trying to connect:
ssh: connect to host x.x.x.x port 22: Operation timed out
One thing I noticed is that I used a different .pem file which is supposed to not work for that instance and the error was the same, it looks like my Mac cannot reach it.
Things already verified:
Security Group allowing traffic over port 22.
Instance rebooted/recreated.
DNS and Public IP address changed after instance reboot.
SSH connection successful over other devices.
SSH connection to other devices from this mac successful.
Firewall turned off.
DNS flushed.
Ping performed with success.
Any help is really appreciated it.
-- UPDATE --
This issue rose in my work machine. Got a different laptop due to other issues and problem fixed, looks like it might have been something related to ports or some sort of configuration. Thought it was a problem with AWS but now it's working fine. Sadly I couldn't debug enough to know what the exact issue was. Thanks to everyone who helped out!
It seems that you can remote by other devices and this issue is only still happening on your MAC. Try this on your MAC and try to remote again:
Flush your DNS
I don't know which Mac OS you are using so I put the link here: (https://help.dreamhost.com/hc/en-us/articles/214981288-Flushing-your-DNS-cache-in-Mac-OS-X-and-Linux)
If still cannot, you can try to open some protocol ports on that instances like:
ICMP, Echo Reply, ...
then try to reach by that protocol commands:
Ping, telnet, ...
If the result is cannot too, so it must be that your MAC cannot even reach to that instance network, then try to ensure that your MAC can reach the instance's network first.
I am using Putty to ssh into some of the servers that I work on. I am able to connect all others except the one. Although I was able to connect to it before. Whenever I try connecting to it, it always give me error:
Unable to open connection on myhost: Host does not exist
My firewall is off and I have even re-installed putty but that did not fix it. When I tried connecting to the same server using putty on some other windows system, I was able to do so. I searched regarding this on Internet but did not find much relevant.
I am running putty on Windows 7.
What can be the possible issue?
As I understand you have three computers involved. At the same time one connection is working and the other one fails. So we can exclude that the ssh daemon on your linux box is hanging.
In lack of knowing their real names I will call your computers linuxbox (this is the computer you want to ssh into), win7ok (that is the computer that you are able to ssh from using putty) and win7fail (that obviously is the computer you can't connect from).
Please do a tracert from both Win7 computers:
tracert linuxbox.your.domain
tracert linuxbox
Add the results to your question as it will help us find out what is happening.
Perhaps it is also a good idea to determine the ip address of the linuxbox from win7ok:
ping linuxbox
or
nslookup linuxbox
Then try to connect from win7fail by using the ip address of the target computer, perhaps it is only a DNS problem (which might be as nmap is failing too).
To make all of this easier to understand for us please provide the real names of the computers as you use them in putty.
For me the problem was with the Url of the reposity. Check remote URL. It must start with git#github.com, not https://.
I used nslookup and then used the ip address it gave me to connect and it worked
I had a similar problem with GitExtensions. The solution was to remove the https url and replace it with git#gitlab....
WRONG:
GOOD:
I just went through this. I have a Cisco VPN I need to use to get through to the Linux machine I wanted to login to and check.
No Putty session would get through using the machines name.
An nslookup on the windows machine yielded the correct address.
I too connected right in via the ip address.
I tried to Google the error and it failed, so I suspected the wireless.
Disconnected and reconnected my WiFi and all was good.
I did it fast enough that open connections stayed open.
And new connections refering to DNS names worked fine.
Seems like maybe some cached DNS addresses were stale.
Your DNS cache stores the locations (IP addresses) of web servers that contain web pages which you have recently viewed. If the location of the web server changes before the entry in your DNS cache updates, you can no longer access the site.
Following CLI command will do the trick:
ipconfig /flushdns
So I've had a Perforce server running on my MacPro for several years. It is set to register itself as xxxxx.dyndns.org, so other users can connect from off my LAN.
Suddenly, today, I can no longer connect via xxxxx.dyndns.org:1666. I get an error:
Connect to server failed; check $P4PORT.
TCP connect to xxxxx.dyndns.org:1666 failed.
connect: some.ip.address.:1666: Connection refused
If I go to a bash shell and do ping xxxxx.dyndns.org, it comes up with some.ip.address and says it pings fine.
So if I can connect via the LAN IP address, and can ping the computer with the dyndns.org address, and the router is set to forward 1666 to the computer hosting the P4 server, what else could be wrong?
Got this answered. Note the use of dyndns.org up there. Their free services have been turned off. I rewired it to use duckdns.org and now it's working fine.
So I have this issue. The issue is I am unable to connect to my red5 server from a remote client. I also have not found any tutorials on how to install red5 so that remote clients can connect to it. However, here is what I have done...
Inside My MXML Flex File I try to connect to the computers IP that the server is running on(My Server is running from within Eclipse). The line for connecting looks like this netConnection.connect(rtmp://192.168.2.12/myApp, true);
All that happens is after a lot of minutes go by, I just get NetConnection.Connect.Failed and there is no log being output by Eclipse. Almost like it never even registers the connection that the remote client is trying to make.
The other interesting thing is that I am ABLE to connect to my Red5 Server using a different computer within my local home network just fine. But only when it is remote I am unable to connect.
I have changed my Red5-web.properties file and added this...
webapp.contextPath=/myApp
webapp.virtualHosts=*, 127.0.0.1, localhost, 192.168.2.14, 174.122.104.3
The 174 one is my website where the Flex Swf Resides on.
I think maybe somehow my computer is not setup or configured to allow these remote connections and is rejecting them or something, I'm not quite sure why a remote client can't connect. Does anyone have any idas?
Your help is greatly appreciated.
You may uninstall the red5 and reinstall it.
When it ask you the server ip address type your server's LAN adress (192.168.2.* or 10.0.0.* whatever). This solved my problem.
In my opinion, if you have at least one domain name that you own, the best way for you to go is to set up an Apache Http Server to your server machine, and create subdomains for both red5, rtmp and rtmpt. Make the Apache handle your incoming requests, and decide their correct routing there.
In case you don't own a domain, or the previous way is too time-taking to set up and get it work, you should just make sure that the ip address you're trying to connect to is not an internal IP.
In your example above you are trying to connect from the client to a 192.168... address. If you try to connect to it from within your LAN, it works, since that ip there is registered to your machine.
But when you take your notebook to your neighbor, and using his internet connection to access your site and connect to red5, the client (flex application) will also try to connect to that 192.168..., and your neighbor's router has no idea about your LAN, probably it doesn't have such an internal IP address either, but SURELY cannot connect to your server.
So instead of using 192.168... in your connection string, you should try using your external IP address (the 174... one):
netConnection.connect("rtmp://174.122.104.3/myApp", true);
This will work always, as far as you have a static IP address.
Also make sure, that your red5 server is accessible over the 80 port, or if it's not, specify the correct port number there.
For that you can do following thing...
These steps I took and it's solved my problem...
1.During the installation, you must have given ip 127.0.0.1 (localhost) and port :5080
2.firstly open the port (5080 and 1935) on firewall.
Visit http://windows.microsoft.com/en-in/windows/open-port-windows-firewall#1TC=windows-7
3.Now to go red5->conf->red5.properties and open this file in notepad++. (or any other editor)
4.repalce http.host and rtmp.host ip with your ip address (ipv4)
5.start the red5 service.
6.Now check http://yourip:5080
It will start working, and you can access it from other system also (in the same network Obviously )