Changed IP - DNS strangely cached?

From: David Croft (
Date: Fri Feb 15 2002 - 14:47:49 EST


I have a config file which specifies each object's 'ip' field as a
hostname rather than an IP address.

A few weeks ago I changed the IP address of one of the monitored machines
in the DNS. I can confirm that this successfully propagated to the
secondary DNS.

However I still get e-mail alerts from sysmon stating "DNS CRITICAL - No
response from server" and "Network is unreachable" on the two services
that are monitored on that machine (dns and smtp). The e-mail shows it is
trying to monitor the OLD ip address.

Interestingly, these services never appear on the sysmon status display,
neither in the curses interface, java client nor html page. The only
problem is the e-mail sent.

I have killed sysmon repeatedly and restarted it. I have confirmed that a
nslookup from that machine returns the correct address. There is nothing
in /etc/hosts. I have tried setting the dnsexpire to 1.

My only guess at this point is that sysmon has a DNS cache file hidden
somewhere but I can't find anything like that.

The only other noteworthy point is that this was previously a /24 network
but it has now been subnetted, so the old address for this machine
(x.x.x.16) is actually now a subnet address. I don't see how this would
affect sysmon keeping the old IP address across a restart.

Any ideas?



|> /+\ \| | |>

David Croft Infotrek

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