migrating to Zabbix

[Danila]

I'm using Nagios to monitor ISP network, wirch is consists of 1000 hosts (switches, routers, radio ethernet bridges). I use "parents" schene to know, is host is DOWN or UNREACHABLE (that info is very importaint for me as we have notifications of our customers if network connection in office goes down). Also, I use SNMP info (traps) to collect from bridges&
Only thing I don't like - there is no parallelizationt in service checks. Couse of it, when one of the nearest to root of tree goes down, monitoring begins to slow - that's the disaster.
So, the quesions:

1. Does Zabbix support parallelized host checks?
2. Does Zabbix support parent-child relations between hosts?
3. Does Zabbix make sence if host's down 'cause of its own problems or 'cause its parent is down?
4. Does Zabbix support maps with layers?

[Alexei]

1. Does Zabbix support parallelized host checks?

Yes. It has been significantly improved in 1.1beta10. Parallelization is controlled by ZABBIX server parameter StartPollers.

2. Does Zabbix support parent-child relations between hosts?

It is supported on triggers level. If a router goes down, notifications about unreachability of hosts behind the firewall will not be sent.

3. Does Zabbix make sence if host's down 'cause of its own problems or 'cause its parent is down?

Yes. It is really up-to ZABBIX administrator to define conditions for considering host is being down or unreachable. It is very flexible.

4. Does Zabbix support maps with layers?

ZABBIX does support hierarchial maps, but not layers (different views of the same map).