Zabbix Applicant 5.2.1 CentOS8 is not accessible by public IP

[sheldonh]

Hi,

I've downloaded and started up the Appliance release 5.2.1. Everything works on the local network, no problems.

I've configured a public IP address on our firewall with routing to the local Zabbix IP address. I can telnet into port 80 via the Public IP address, but I cannot open HTTP via any web browser. I've tried stopping iptables to see if there's routing rules stopping incoming traffic, but that does not help.

Any ideas?

Thanks

[tim.mooney]

I haven't looked at the appliance so I don't know for certain, but RHEL 8.x and CentOS 8.x have moved away from 'iptables/ip6tables' and now use 'nftables', generally with 'firewalld' as an "abstraction layer' in front of the backend nftables implementation.

[sheldonh]

I haven't looked at the appliance so I don't know for certain, but RHEL 8.x and CentOS 8.x have moved away from 'iptables/ip6tables' and now use 'nftables', generally with 'firewalld' as an "abstraction layer' in front of the backend nftables implementation.

Hi Tim,

Thanks for the feedback.

Unfortunately, the appliance I downloaded using CentOS8 does not have firewalld or nftables running. It also does not run on Apache, it runs on Nginx. I only see iptables as options for me to configure. If stopped iptables service, I still get the same behaviour. I've also tried to modify the Nginx conf files to see if I can get something right. I'm sharing here for reference:



Here is the iptables file itself




This is the zabbix.conf file under /etc/nginx/conf.d/zabbix.conf




Maybe with your knowledge you can spot something wrong?

[sheldonh]

bumping up

[LenR]

Start tcpdump on the web server watching for your inbound traffic. Then test with a browser. That will tell us if the traffic is getting there or not. You might also check the nginx logs. I haven;t used nginx much, but when I have, it just worked, so I don't have any debugging experience :-)

[sheldonh]

Start tcpdump on the web server watching for your inbound traffic. Then test with a browser. That will tell us if the traffic is getting there or not. You might also check the nginx logs. I haven;t used nginx much, but when I have, it just worked, so I don't have any debugging experience :-)

Thanks LenR, I've been able to confirm that I can receive inbound traffic over internet by monitoring over tcpdump. What seems to happen is that there is no response to the inbound requests. It's like the server blocks and responses or something. So SYN packets received, no ACK packets sent back.