Zabbix Connectivity Issue On Server with Multiple Network Interfaces...

[Cossy]

Dear Zabbix Forum Communuity,

I am in the process of deploying Zabbix(5.0.3) on to a Red Hat(8.7) server with two network interfaces, eth0 configured with a dynamic ip address and eth1 configured with a static ip address.

I am able to connect to the Zabbix portal using its dynamic ip address on eth0 and also able to successfully authenticate.

I am not, however, able to connect to the static ip address on eth1 and was looking for a little guidance as to what the issue might be.

I am able to telnet to port 80 on the Zabbix servers static ip address so its not a firewall type issue. This was verified using 'tcpdump -i eth1'.

Following a quick search of similar issues, I have seen references to the 'Server' and 'ServerActive' parameters in the 'zabbix_agentd.conf' file although uncovinced by these as I was under the impression that the agent is used to gather local server metrics that are then sent to the Zabbix manageent server rather than anything to to with connectivity from a browser to the management servers portal to administer the Zabbix application.

Can anyone clarify the role of the zabbix-agent service running on the managemnent server with regards to Web portal connectivity as well as shedding any light on why I am able to connect to the dynamic ip address on interface eth0 but not the static ip address on interface eth1.

'zabbix_agentd.conf'
Server=10.107.7.10
ServerActive=zabbix.local.com

Some environmental information:

cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.7 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.7"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.7 (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8::baseos"
HOME_URL="https://www.redhat.com/"
DOCUMENTATION_URL="https://access.redhat.com/documentation/red_hat_enterprise_linux/8/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.7
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.7" zz0.k78mh795p7zz

rpm -qa | grep -i zabbix
zabbix-sender-5.0.31-1.el8.x86_64
zabbix-web-5.0.31-1.el8.noarch
zabbix-web-mysql-5.0.31-1.el8.noarch
zabbix-agent-5.0.31-1.el8.x86_64
zabbix-server-mysql-5.0.31-1.el8.x86_64
zabbix-web-deps-5.0.31-1.el8.x86_64

systemctl status zabbix-agent.service
● zabbix-agent.service - Zabbix Agent
Loaded: loaded (/etc/systemd/system/zabbix-agent.service; enabled; vendor preset: disabled)
Active: active (running) since Mon 2023-05-08 10:03:21 BST; 1h 7min ago
Main PID: 37236 (zabbix_agentd)
Tasks: 6 (limit: 22285)
Memory: 3.9M
CGroup: /system.slice/zabbix-agent.service
├─37236 /usr/sbin/zabbix_agentd --foreground -c /etc/zabbix/zabbix_agentd.conf
├─37237 /usr/sbin/zabbix_agentd: collector [idle 1 sec]
├─37238 /usr/sbin/zabbix_agentd: listener Home [waiting for connection]
├─37239 /usr/sbin/zabbix_agentd: listener Forum [waiting for connection]
├─37240 /usr/sbin/zabbix_agentd: listener #3 [waiting for connection]
└─37241 /usr/sbin/zabbix_agentd: active checks Home [idle 1 sec]

May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37236]: IPv6 support: YES
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37236]: TLS support: YES
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37236]: **************************
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37236]: using configuration file: /etc/zabbix/zabbix_agentd.conf
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37236]: agent #0 started [main process]
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37237]: agent Home started [collector]
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37238]: agent Forum started[listener #1]
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37240]: agent #4 started[listener #3]
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37239]: agent #3 started[listener #2]
May 08 10:03:21 zabbix2-i0227f7debcb123503 zabbix_agentd[37241]: agent #5 started [active checks #1]


systemctl status zabbix-server.service
● zabbix-server.service - Zabbix Server
Loaded: loaded (/etc/systemd/system/zabbix-server.service; enabled; vendor preset: disabled)
Active: active (running) since Sun 2023-05-07 17:42:33 BST; 17h ago
Docs: man:zabbix_server
Main PID: 18429 (zabbix_server)
Tasks: 58 (limit: 22285)
Memory: 714.7M
CGroup: /system.slice/zabbix-server.service
├─18429 /usr/sbin/zabbix_server --foreground -c /etc/zabbix/zabbix_server.conf
├─18487 /usr/sbin/zabbix_server: configuration syncer [synced configuration in 0.131284 sec, idle 60 sec]
├─18494 /usr/sbin/zabbix_server: alert manager Home [sent 0, failed 0 alerts, idle 5.015262 sec during 5.015303 sec]
├─18495 /usr/sbin/zabbix_server: alerter Home [sent 0, failed 0 alerts, idle 80.000547 sec during 120.000762 sec]
├─18496 /usr/sbin/zabbix_server: alerter Forum [sent 0, failed 0 alerts, idle 80.000627 sec during 120.000773 sec]
├─18497 /usr/sbin/zabbix_server: alerter #3 [sent 0, failed 0 alerts, idle 80.000597 sec during 120.000767 sec]
├─18498 /usr/sbin/zabbix_server: preprocessing manager Home [queued 0, processed 22 values, idle 5.001328 sec during 5.001513 sec]
├─18499 /usr/sbin/zabbix_server: preprocessing worker Home started
├─18500 /usr/sbin/zabbix_server: preprocessing worker Forum started
├─18501 /usr/sbin/zabbix_server: preprocessing worker #3 started
├─18502 /usr/sbin/zabbix_server: lld manager Home [processed 0 LLD rules, idle 5.005271sec during 5.005273 sec]
├─18503 /usr/sbin/zabbix_server: lld worker Home [processed 1 LLD rules, idle 321.066713 sec during 321.106522 sec]
├─18504 /usr/sbin/zabbix_server: lld worker Forum [processed 1 LLD rules, idle 321.081365 sec during 321.107022 sec]
├─18505 /usr/sbin/zabbix_server: housekeeper [deleted 740 hist/trends, 0 items/triggers, 0 events, 0 sessions, 0 alarms, 0 audit items, 0 records in>
├─18506 /usr/sbin/zabbix_server: timer Home [updated 0 hosts, suppressed 0 events in 0.009651 sec, idle 59 sec]
├─18507 /usr/sbin/zabbix_server: http poller Home [got 0 values in 0.000738 sec, idle 5 sec]
├─18508 /usr/sbin/zabbix_server: discoverer Home [processed 0 rules in 0.000000 sec, performing discovery]
├─18509 /usr/sbin/zabbix_server: discoverer Forum [processed 0 rules in 0.000787 sec, idle 60 sec]
├─18510 /usr/sbin/zabbix_server: discoverer #3 [processed 0 rules in 0.000723 sec, performing discovery]
├─18511 /usr/sbin/zabbix_server: history syncer Home [processed 0 values, 1 triggers in 0.000606 sec, idle 1 sec]
├─18512 /usr/sbin/zabbix_server: history syncer Forum [processed 0 values, 0 triggers in 0.000008 sec, idle 1 sec]
├─18513 /usr/sbin/zabbix_server: history syncer #3 [processed 0 values, 0 triggers in 0.000007 sec, idle 1 sec]
├─18514 /usr/sbin/zabbix_server: history syncer #4 [processed 0 values, 0 triggers in 0.000007 sec, idle 1 sec]
├─18515 /usr/sbin/zabbix_server: history syncer #5 [processed 0 values, 0 triggers in 0.000006 sec, idle 1 sec]
├─18516 /usr/sbin/zabbix_server: history syncer Special [processed 0 values, 0 triggers in 0.000007 sec, idle 1 sec]
├─18517 /usr/sbin/zabbix_server: history syncer #7 [processed 0 values, 0 triggers in 0.000007 sec, idle 1 sec]
├─18518 /usr/sbin/zabbix_server: history syncer Private Messages [processed 0 values, 0 triggers in 0.000012 sec, idle 1 sec]
├─18519 /usr/sbin/zabbix_server: history syncer Albums [processed 0 values, 0 triggers in 0.000007 sec, idle 1 sec]
├─18520 /usr/sbin/zabbix_server: history syncer #10 [processed 0 values, 0 triggers in 0.000013 sec, idle 1 sec]
├─18521 /usr/sbin/zabbix_server: history syncer #11 [processed 0 values, 0 triggers in 0.000007 sec, idle 1 sec]
├─18522 /usr/sbin/zabbix_server: history syncer CSS Examples [processed 5 values, 5 triggers in 0.009704 sec, idle 1 sec]
├─18523 /usr/sbin/zabbix_server: escalator Home [processed 0 escalations in 0.001441 sec, idle 3 sec]
├─18524 /usr/sbin/zabbix_server: proxy poller Home [exchanged data with 0 proxies in 0.000006 sec, idle 5 sec]
├─18525 /usr/sbin/zabbix_server: self-monitoring [processed data in 0.000008 sec, idle 1 sec]
├─18526 /usr/sbin/zabbix_server: task manager [processed 0 task(s) in 0.000664 sec, idle 5 sec]
├─18527 /usr/sbin/zabbix_server: poller Home [got 4 values in 0.000292 sec, idle 1 sec]
├─18528 /usr/sbin/zabbix_server: poller Forum [got 0 values in 0.000003 sec, idle 1 sec]
├─18529 /usr/sbin/zabbix_server: poller #3 [got 0 values in 0.000004 sec, idle 1 sec]
├─18530 /usr/sbin/zabbix_server: poller #4 [got 0 values in 0.000004 sec, idle 1 sec]
├─18531 /usr/sbin/zabbix_server: poller #5 [got 1 values in 0.000370 sec, idle 1 sec]
├─18532 /usr/sbin/zabbix_server: poller Special [got 0 values in 0.000003 sec, idle 1 sec]
├─18533 /usr/sbin/zabbix_server: poller #7 [got 0 values in 0.000005 sec, idle 1 sec]
├─18534 /usr/sbin/zabbix_server: poller Private Messages [got 0 values in 0.000005 sec, idle 1 sec]
├─18535 /usr/sbin/zabbix_server: poller Albums [got 0 values in 0.000003 sec, idle 1 sec]

systemctl status httpd.service
● httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
Drop-In: /usr/lib/systemd/system/httpd.service.d
└─php-fpm.conf
Active: active (running) since Sun 2023-05-07 17:43:10 BST; 17h ago
Docs: man:httpd.service(8)
Process: 29761 ExecReload=/usr/sbin/httpd $OPTIONS -k graceful (code=exited, status=0/SUCCESS)
Main PID: 20126 (httpd)
Status: "Total requests: 1346; Idle/Busy workers 90/10;Requests/sec: 0.0214; Bytes served/sec: 60 B/sec"
Tasks: 11 (limit: 22285)
Memory: 16.8M
CGroup: /system.slice/httpd.service
├─20126 /usr/sbin/httpd -DFOREGROUND
├─29762 /usr/sbin/httpd -DFOREGROUND
├─29763 /usr/sbin/httpd -DFOREGROUND
├─29764 /usr/sbin/httpd -DFOREGROUND
├─29765 /usr/sbin/httpd -DFOREGROUND
├─29766 /usr/sbin/httpd -DFOREGROUND
├─29767 /usr/sbin/httpd -DFOREGROUND
├─29768 /usr/sbin/httpd -DFOREGROUND
├─29769 /usr/sbin/httpd -DFOREGROUND
├─36448 /usr/sbin/httpd -DFOREGROUND
└─36449 /usr/sbin/httpd -DFOREGROUND

May 07 17:43:10 zabbix2-i0227f7debcb123503 systemd[1]: Starting The Apache HTTP Server...
May 07 17:43:10 zabbix2-i0227f7debcb123503 systemd[1]: Started The Apache HTTP Server.
May 07 17:43:10 zabbix2-i0227f7debcb123503 httpd[20126]: Server configured, listening on: port 80
May 08 03:06:01 zabbix2-i0227f7debcb123503 systemd[1]: Reloading The Apache HTTP Server.
May 08 03:06:01 zabbix2-i0227f7debcb123503 httpd[20126]: Server configured, listening on: port 80
May 08 03:06:02 zabbix2-i0227f7debcb123503 systemd[1]: Reloaded The Apache HTTP Server.

systemctl status php-fpm.service
● php-fpm.service - The PHP FastCGI Process Manager
Loaded: loaded (/usr/lib/systemd/system/php-fpm.service; enabled; vendor preset: disabled)
Active: active (running) since Sun 2023-05-07 17:43:04 BST; 17h ago
Main PID: 19783 (php-fpm)
Status: "Processes active: 0, idle: 12, Requests: 1349, slow: 0, Traffic: 0.1req/sec"
Tasks: 13 (limit: 22285)
Memory: 113.7M
CGroup: /system.slice/php-fpm.service
├─19783 php-fpm: master process (/etc/php-fpm.conf)
├─19784 php-fpm: pool www
├─19785 php-fpm: pool www
├─19786 php-fpm: pool www
├─19787 php-fpm: pool www
├─19788 php-fpm: pool www
├─19789 php-fpm: pool zabbix
├─19790 php-fpm: pool zabbix
├─19791 php-fpm: pool zabbix
├─19792 php-fpm: pool zabbix
├─19793 php-fpm: pool zabbix
├─35055 php-fpm: pool zabbix
└─35493 php-fpm: pool zabbix

May 07 17:43:04 zabbix2-i0227f7debcb123503 systemd[1]: Starting The PHP FastCGI Process Manager...
May 07 17:43:04 zabbix2-i0227f7debcb123503 systemd[1]: Started The PHP FastCGI Process Manager.

[cyber]

zabbix_agentd.conf is for agent config. Your server config is in zabbix_server.conf probably under /etc/zabbix and your frontend config is somewhere under httpd files ... I guess its the frontend config you need to overview...

[Cossy]

Hi Cyber,

Thanks for advice.

I've had a good look at the zabbix_server.conf file(see below) and there is nothing obvious in there that relates to the Zabbix server listening on all configured interfaces.

Are you able to provide any further advice?

Thanks.

Contents of 'zabbix_server.conf' file...

ListenPort=10051
SourceIP=10.107.7.10
LogType=system
DebugLevel=3
PidFile=/var/run/zabbix/zabbix_server.pid
DBHost=zabbixdb2-xxx.com
DBName=zabbix_server
DBUser=xxxx
DBPassword=xxxx
StartPollers=10
StartIPMIPollers=0
StartPreprocessors=3
StartPollersUnreachable=1
StartTrappers=10
StartPingers=1
StartDiscoverers=3
StartHTTPPollers=1
StartTimers=1
StartEscalators=1
StartAlerters=3
StartVMwareCollectors=0
VMwareFrequency=60
VMwareCacheSize=8M
SNMPTrapperFile=/tmp/zabbix_traps.tmp
StartSNMPTrapper=0
HousekeepingFrequency=1
MaxHousekeeperDelete=500
CacheSize=32M
CacheUpdateFrequency=60
StartDBSyncers=12
HistoryCacheSize=64M
TrendCacheSize=4M
ValueCacheSize=64M
Timeout=3
TrapperTimeout=300
UnreachablePeriod=45
UnavailableDelay=60
UnreachableDelay=15
AlertScriptsPath=/etc/zabbix/alertscripts
ExternalScripts=/usr/lib/zabbix/externalscripts
FpingLocation=/usr/sbin/fping
Fping6Location=/usr/sbin/fping6
LogSlowQueries=0
TmpDir=/tmp
StartProxyPollers=1
ProxyConfigFrequency=3600
ProxyDataFrequency=1
StartLLDProcessors=2
AllowRoot=1
User=zabbix
Include=/etc/zabbix/zabbix_server.conf.d (<- This directory is empty so there ar not additional files.)
SSLCertLocation=/usr/lib/zabbix/ssl/certs
SSLKeyLocation=/usr/lib/zabbix/ssl/keys
LoadModulePath=/usr/lib/modules

[cyber]

https://www.zabbix.com/documentation/current/en/manual/appendix/config/zabbix_server#listenip

I have a feeling, that this setup with multiple IP-s does not play well with your webserver config... But that's just a feeling...

[Cossy]

The ListenIP parameter appears to relate to the SNMP trapper, not the web portal. Also, if it's not configured, as in my situation, it should listen on all interfaces...

### Option: ListenIP
# List of comma delimited IP addresses that the trapper should listen on.
# Trapper will listen on all network interfaces if this parameter is missing.
#

Im not sure how strong your 'feeling' is but I dont think this is the source of my problem.

[cyber]

As you said

I've had a good look at the zabbix_server.conf file(see below) and there is nothing obvious in there that relates to the Zabbix server listening on all configured interfaces.

Then I answered to that .. Should have quoted it correctly...

yes.. server IP and web interface things are different... You probably should look up that apache config, but I cannot really give any good suggestions here...

[Cossy]

No problem and thanks for your help Cyber.

Cossy

[Cossy]

This issue has now been resolved and was caused by a local routing issue at the o/s level and therefore nothing to do with Zabbix at all.

Ticket closed.