Received empty response from Zabbix Agent - monitoring

I have zabbix installed on my wan ip and I'm able to add clients in that of same Wan Ip network, But when i'm trying to add a zabbix client of different Wan network range, i'm getting -
Received empty response from Zabbix Agent at [xx.xx.xx.xx]. Assuming
that agent dropped connection because of access permission.
There is no filtering at any end, and i have cross checked zabbix_agentd.conf file may times and found no errors. I can see ports listening at 10050 on client servers.

The Troubleshooting page on Zabbix.org is a classical reference for troubleshooting unreachable agents.
In this particular case, you might wish to start with checking that Zabbix server IP is listed in agent's Server configuration parameter.

I have solved the above problem. it was my router's wan ip that was collecting the data from zabbix agent and not the zabbix server's wan ip.
so i gave both the ips of my router as well as of zabbix server in zabbix_agentd.conf's Server and ServerActive . and now its working fine.
Thanks

Related

edited how to make nginx pont to my mosquitto broker in docker [duplicate]

I have a server and I am using Ubuntu 20.04, nginx , mosquitto and node-red and docker , let's call the website http://mywebsite.com. The problem that I am facing that I have created a client lets call it client1 in docker so the URL will be http://mywebsite.com/client1
and I want to establish an MQTT connection via mosquitto and I'm sending the data on topic test
The problem that on node red node of MQTT when I write the IP address of my mosquitto container it works
But if I change the IP address 192.144.0.5 with mywebsite.com/client1 I can't connect to mosquitto and I can't send or receive any form of data
any idea on how to solve this problem
OK, you are going to have several problems here.
You can not do path based proxying with MQTT. If you want to have multiple MQTT brokers (1 per client) bound to a single public facing domain/IP address then they are all going to have to run on separate ports (other than the default 1883).
Nginx can do MQTT protocol proxying (e.g. like this), so you can use this to expose the different ports and forward them to the separate instances of mosquitto, but even if you had a different hostname (all pointing at the same IP address) nginx has no way to know which host name was used because there is no equivalent to the HOST HTTP header to direct it. If you were to use MQTT with TLS then you may be able to get it to work with SNI, but I've never seen anybody do that yet (possible docs for SNI based routing here) It works, explanation about how to do it here.
If you use MQTT over Websockets then you should be able to use hostname based routing.
Path based proxying for Node-RED currently doesn't work properly if you enable admin authentication, because the admin auth tokens are currently stored in browser local storage and only scoped to the hostname, not the hostname + path. This will mean that a client will only ever be able to log into one instance at a time.
You can work round this by using host based proxying, e.g. http://client1.mywebsite.com
A fix for this is on the backlog for Node-RED, probably (no promises) to be looked at after version 1.2.0 ships

Port forwarding, DMZ, turning off firewall and adding port doesn't work to reach out port

I am using Windows 10 with IIS 10.0
I am publishing website on IIS and I need to reach it with public ip.
What I did;
* Port forwarding through router
* Adding DMZ with my local IP
* Turning off firewall
* Adding port to firewall inbound rules with allow edge traversal
I can connect with internal IP like 192.168.1.75:81
I get "System.Net.Sockets.SocketException A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond from [MYPUBLICIP]" when I try to reach it like MYPUBLICIP:81
What are the possible scenarios that blocks to port?
Thanks.
As far as I know, the error message means there is no server listening at specified ip/port that you are trying to connect to.
In my opinion, you should firstly make sure your client machine could access your server by using this MYPUBLICIP address.
Then I suggest you could try to make sure the port 81 is your IIS web application port.
Besides, I suggest you could try to open your event viewer to find out the details error message.

Zabbix Web Monitoring without interfaces

I want to send HTTP request to a website where I can't deploy a Zabbix agent. I can only access the website via HTTP / HTTPS.
I created a host, but I had to setup a false interface (I wrote Zabbix Agent / the website DNS and port 10050). Consequently, the status is "Red" as Zabbix Server cannot connect to the agent.
How can I set up an agent without any interfaces, or more precisely, without triggering a "Red" status on the host ? In my situation, is there any way to get a "Green" status on the host ?
Zabbix version : 3.2.11
At least one interface is mandatory. Using 127.0.0.1 the status is Enabled, green. I'm using Zabbix 4 here.
Hosts in Zabbix must have at least one interface. That interface does not have to be used.
If you see the red "Z" and an error about contacting the agent, this means that you have created Zabbix agent items on that host (directly or via linking some template).
As those items do not work, it would be best to remove them.
See http://www.zabbixbook.com/2016/11/22/can-i-have-a-host-without-interfaces/ for more information.

Active zabbix agents are becoming unavailable due to DHCP IP change

I am using active Zabbix agents that auto-register themselves to the Zabbix server.
Everything goes well until the DHCP changes the host IP, the host then becomes unavailable in Zabbix... Looking at the host under the hosts list in Zabbix frontend, I can see that it had the old IP.
Is there any way to solve this?
This means that you are actually not using active items. I'd suggest cloning your current template and changing items, LLD rules and LLD prototypes to "Zabbix agent (active)" - then agent IP address changes will not be a concern.

Remote connection to Neo4j server

I believe the way to creating a remote connection is by changing this line in conf/neo4j-server.properties, specifically by removing the comment and restarting the server.
org.neo4j.server.webserver.address=0.0.0.0
My URL is https://0.0.0.0:7473/browser/ and works on the local machine, but when I test the URL in Safari on iPhone over 3G, it cannot connect.
What do I set the address to in the properties file?
I thought it was the IP address of my computer, but after trying the remote address which I got from Googling “ip address mac” that didn’t work, nor did (obviously) the local IP address of my machine, 192.168.0.14
I should point out that setting it to the IP address from Google throws an error and the log reads:
2015-01-29 17:10:08.888+0000 INFO [API] Failed to start Neo Server on port [7474], reason [MultiException[java.net.BindException: Can't assign requested address, java.net.BindException: Can't assign requested address]]
With default configuration Neo4j only accepts local connections
In neo4j-community-3.1.0 edit conf/neo4j.conf file and uncomment the following to accept non-local connections
dbms.connectors.default_listen_address=0.0.0.0
By setting
org.neo4j.server.webserver.address=0.0.0.0
enables Neo4j on all network interfaces.
The remainder of that reply is not Neo4j related at all - it's regular networking. Double check if port 7473 (and/or 7474) are not blocked neither be a locally running firewall nor by your router. You local IP 192.168.0.14 indicates you're behind a router doing NAT. Therefore you have to setup a port forwarding in your router for the ports mentioned above.
Please be aware that this is potentially dangerous since everyone knowing your external IP can access your Neo4j instance. Consider using either https://github.com/neo4j-contrib/authentication-extension or use a VPN in favour of port forwarding.
in 3.0:
##### To have HTTP accept non-local connections, uncomment this line
dbms.connector.http.address=0.0.0.0:7474
Confused myself with the setting. Anyone who has the same problem, 0.0.0.0 just means “this server isn’t local any more” and so to access it you use the public IP address of the computer that’s hosting the Neo4j server.
Just make sure that the ports you set in the server properties (default are 7474 and 7473) are open for incoming connections on your router/firewall etc.
I think there's some confusion here. That configuration property org.neo4j.server.webserver.address is about which IP address the server you're starting listens on for external connections. Relevant documentation is here.
It seems you're asking how to configure your database to talk to a remote database. I don't think you can do that. Rather, by editing that file you're planning on running a database on the host where that file is. Your local database on that host will write files to wherever the org.neo4j.server.database.location configuration parameter points.
A remote connection is something that the neo4j shell might establish, or that you browser might make to a foreign server running neo4j; but you don't establish that sort of remote connection by editing that file. Hopefully this helps.
Also if you have ssh access to remote server with neo4j you can setup ssh tunnel to access it via localhost:
ssh -NfL localhost:7474:localhost:7474 -L localhost:7687:localhost:7687 yourname#yourhost
then type in browser:
localhost:7474
Depends on the version.
Look for the phrase 'non-local connections' in the conf file.(In my case, $NEO4J_HOME/conf/neo4j.conf)
Then follow the instructions in the comments.
In my case,
# With default configuration Neo4j only accepts local connections.
# To accept non-local connections, uncomment this line:
server.default_listen_address=0.0.0.0

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