[Nagiosplug-devel] nagios check_carp for OpenBSD carp(4)

[Brian A. Seklecki]

Thoughts? Strategies? Ideas?
---

Ask the machine directly? Ask an adjacent machine?

Adjacent machine strat:

If the monitoring machine is directly connected to the same ethernet
segment, one could use pcap(3) to examine multicast packets.  There are
no utils I know of that do this, so a few lines of C probably.

If the monitoring machine is more than one layer-3 device away or in a
separate broadcast domain, an agent would have to be installed directly
on the device or a device on the same segment.

Machine directly:

Agent Options:

- Net-SNMP via PF-MIB (possibly via AgentX) - use check_snmp
- Net-SNMP via pass through MIB and script  - use check_snmp (maybe
  return an Integer as a boolean w/:   -c "0:0" -w "0:0")
- NRPE2 w/ SSL and - use check_nrpe (NRPE2 isn't in OpenBSD Ports)
- SSH (via check_ssh and passphrase-less RSA/DSA Keys)

Options for On-system:

- Shell/Perl script to parse ifconfig(8)
- C utility to ask /dev/pf pf(4)
- Examine klog(9) for net.inet.carp.log=

----

Other thoughts:

Preempt: Unlike "HSRP Groups" where interfaces can preempt can apply to
select group of interfaces, it is safe to assume that if preempt is
enabled and one interface in a SLAVE state; all other are in that
state.  

Perhaps 4.0 features such as interface groups and multi-routing tables
will change that.

Other ideas?

-- 
Brian A. Seklecki <bseklecki at collaborativefusion.com>
Collaborative Fusion, Inc.