zabbix server with 2 IPs

[nerijus]

Hello,

we ve'got 2nd internet connection and now our zabbix server makes outgoing connections from 2 IPs (an outgoing traffic is balanced). We have Server=server.example.com in clients' zabbix_agentd.conf, and server.example.com resolves to both server IPs. But it seems connections from new 2nd IP are dropped. Why?

[phasevelocity]

Do you have both ip's in the client's config file?

[nerijus]

I have Server=server.example.com, which resolves to both IPs.

[phasevelocity]

How does this hostname resolve to multiple ips?

[nerijus]

nslookup server.example.com
Server: 127.0.0.1
Address: 127.0.0.1#53

Non-authoritative answer:
Name: server.example.com
Address: 81.7.90.xx
Name: server.example.com
Address: 86.100.202.xx - this is a new IP

[phasevelocity]

Maybe you can get some info from the Zabbix client logs.
Don't forget to set the logging level to 5.

[nerijus]

24429:20090208:160257 In disable_all_metrics()
24429:20090208:160257 Parsed [ZBX_EOF]
24429:20090208:160257 In process_active_checks('server.example.com',10051)
24429:20090208:160257 In get_min_nextcheck()
24429:20090208:160257 Sleeping for 60 seconds
24426:20090208:160303 Processing request.
24426:20090208:160303 In check_security()
24426:20090208:160303 Listener error: Connection from [81.7.90.xx] rejected. Allowed server is [server.example.com]

It seems zabbix agent does not support DNS hosts which resolve to multiple IPs.

[makini]

It can't have 2 ip's for one hostname

Here's the agentd.conf description for "Server=..." (from an old version):

# List of comma delimited IP addresses (or hostnames) of ZABBIX servers.
# No spaces allowed. First entry is used for sending active checks.
# Note that hostnames must resolve hostname->IP address and
# IP address->hostname.

Seems like you'd have to add both servers' ip addresses to the agents, each server must have a separete hostname resolving to a single ip - agents and servers obviously not designed for DNS round-robin. I'd recommend using some other load-balancing method, maybe Zabbix's proxies or maybe BGP load-balancing with single IP for the zabbix server, via both your ISP connections (if that's possible of course - you got'ta have PA ip addresses, AS num. & etc).

[phasevelocity]

Depending on what you want to achieve an alternative solution could be to use 2 servers.
It is possible to have 2 agents on a host with: --multiple-agents
This will install multiple agents on the monitored server and allow you to send data to multiple servers.