Cacti reporting downed hosts as up!

[karmacop]

I recently decided to try and migrate over to cactid from the php poller. I attempted to compile the source version on my ubuntu box but configure told me i needed sql and snmp headers. I apt-get'd the sql headers which also upgraded my sql-common files, got the snmp stuff too. I also changed all the paths in my data inpute methods to use full paths, as per the cactid install guide.
I then compiled and started using cactid.

Anyway to my horror, cacti has started showing my inactive hosts as active.
E.G. I have a host im working on getting up and running, im having some firewall issues with it, so it doesnt respond to ping or snmp. Somehow cacti is getting ping responses from it (but the snmp still shows as down).

I tried changing back to the php poller, but no cigar, im considering restoring a cacti db backup from the last day or so, but am not sure if that will make any difference?

This is a real issue for me, and any help would be much appreciated.

[gandalf]

Cacti will report ALLL hosts as up, if no community string has been given. This will force cacti to leave out all downed host checks. Please read second link of my signature carefully to track this down.
Cacti 0.8.7 annouces per-host downed-host-detection
Reinhard

[karmacop]

Most of the devices have a community string set, apart from a couple that arnt snmp capable. But everything is still showing as up.
As i said, cacti is displaying data for average and current ping times, even tho the device is unreachable!
It was all working perfectly before i updated my sql, i take half daily backups, so id also like to know how easy it would be to rstore a database from early last week? Would cacti handle that ok?

[gandalf]

As i said, cacti is displaying data for average and current ping times, even tho the device is unreachable!

Well, that's magic! Please select one of those magic graphs at Graph Management. Swicth to debug mode and note the rrd files mentioned on the DEF statements. Find those at Data Sources. Are they related to the correct host?
Reinhard