nagios-users

[Nagios-users] check_ping vs check_icmp?

[Rogelio B. <scu...@gm...>]

I just recently noticed that there is a check_ping and a check_icmp plugin.

I ran "./check_plugin --help" on each, but am still unclear as to what
each does differently.  Does check_icmp include traceroute and other
non-ping ICMP checks?

Re: [Nagios-users] check_ping vs check_icmp?

[Holger W. <ho...@CI...>]

* Rogelio Bastardo <scu...@gm...> [2007-07-30 10:37]:
> I just recently noticed that there is a check_ping and a check_icmp plugin.
>
> I ran "./check_plugin --help" on each, but am still unclear as to what
> each does differently.

Unlike check_ping, check_icmp allows for checking multiple hosts at
once; the behaviour is more configurable; and it generates performance
data output.  But the main difference is that check_ping executes the
system's ping(1) command and parses its output while check_icmp talks
ICMP itself.  This usually means that check_icmp must be installed
setuid root, but also that its performance is much better.  Given that
Nagios 2.x holds off on doing anything else while performing host
checks, this might be an important advantage.

So, if you don't mind installing the plugin setuid root, I'd recommend
using check_icmp.

> Does check_icmp include traceroute and other non-ping ICMP checks?

No.

Holger

-- 
PGP fingerprint:  F1F0 9071 8084 A426 DD59  9839 59D3 F3A1 B8B5 D3DE

Re: [Nagios-users] check_ping vs check_icmp?

[Marc P. <ma...@en...>]

> -----Original Message-----
> From: nag...@li... [mailto:nagios-users-
> bo...@li...] On Behalf Of Rogelio Bastardo
> Sent: Monday, July 30, 2007 12:37 PM
> To: Nagios Users mailinglist
> Subject: [Nagios-users] check_ping vs check_icmp?
>=20
> I just recently noticed that there is a check_ping and a check_icmp
> plugin.
>=20
> I ran "./check_plugin --help" on each, but am still unclear as to what
> each does differently.  Does check_icmp include traceroute and other
> non-ping ICMP checks?

check_ping is a wrapper for /bin/ping and so depends on that program to
actually perform the check, parsing it's output to determine success or
not. check_icmp performs the check itself. check_icmp is much more
efficient than check_ping, typically completing in fractions of a second
for 10 pings. Here's a graphic example, 50 pings, 49 seconds for
check_ping v.s. 1.2 seconds for check_icmp --

$ time ./check_ping -n 50 -H www.ena.com -w500,50% -c 1000,100%
PING OK - Packet loss =3D 0%, RTA =3D 1.78 ms

real    0m49.197s
user    0m0.000s
sys     0m0.020s

time ./check_icmp -n 50 -H www.ena.com -w500,50% -c 1000,100%
OK - www.ena.com: rta 0.40 ms, lost 0%|rta=3D0.40ms;500;1000;;
pl=3D0%;50;100;;

real    0m1.229s
user    0m0.530s
sys     0m0.700s

--
Marc

Re: [Nagios-users] check_ping vs check_icmp?

[Rogelio B. <scu...@gm...>]

> So, if you don't mind installing the plugin setuid root, I'd recommend
> using check_icmp.

Forgive my ignorance, but where can I find this?

(I googled for "setuid root nagios check_icmp" but nothing jumped out at me)

Re: [Nagios-users] check_ping vs check_icmp?

[Rogelio B. <scu...@gm...>]

On 7/30/07, Rogelio Bastardo <scu...@gm...> wrote:
> > So, if you don't mind installing the plugin setuid root, I'd recommend
> > using check_icmp.
>
> Forgive my ignorance, but where can I find this?
>
> (I googled for "setuid root nagios check_icmp" but nothing jumped out at me)

ah, I see it's a package

"yum install nagios-plugins-setuid"

thanks again for your help, guys.

Re: [Nagios-users] check_ping vs check_icmp?

[Marc P. <ma...@en...>]

> -----Original Message-----
> From: nag...@li... [mailto:nagios-users-
> bo...@li...] On Behalf Of Rogelio Bastardo
> Sent: Monday, July 30, 2007 6:22 PM
> To: Nagios Users
> Subject: Re: [Nagios-users] check_ping vs check_icmp?
>=20
> On 7/30/07, Rogelio Bastardo <scu...@gm...> wrote:
> > > So, if you don't mind installing the plugin setuid root, I'd
recommend
> > > using check_icmp.
> >
> > Forgive my ignorance, but where can I find this?
> >
> > (I googled for "setuid root nagios check_icmp" but nothing jumped
out at
> me)
>=20
> ah, I see it's a package

Actually, this is terminology detailing how a specific set of
permissions are applied to a file/program. Basically, setuid and setgid
mean that a flag is applied to the file/program with chmod such that it
will retain it's ownership for that bit when being used. For the
purposes here, setuid root means that the file should be owned by the
user root (chown root /path/to/check_icmp) and setuid (chmod u+s
/path/to/check_icmp). This will cause check_icmp to always run as the
root user no matter who is running it. This allows it to open the
necessary socket connections without requiring that the actual root user
be running it. setuid is denoted by the 's' below --

$ ls -l /usr/local/nagios/libexec/check_icmp=20
-r-sr-xr-x    1 root     nagios      15424 Jun  9 21:42
/usr/local/nagios/libexec/check_icmp

$ ls -l /bin/ping
-rwsr-xr-x    1 root     root        27860 Sep 29  2005 /bin/ping

--
Marc