Instalando NRPE para monitorear uno de los servidores encontré problemas de dependencias con libcrypto y libssl:

yum install nrpe.x86_64
Loaded plugins: product-id, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package nrpe.x86_64 0:2.15-2.el6 will be installed
--> Processing Dependency: nagios-common for package: nrpe-2.15-2.el6.x86_64
--> Processing Dependency: libssl.so.10(libssl.so.10)(64bit) for package: nrpe-2.15-2.el6.x86_64
--> Processing Dependency: libcrypto.so.10(libcrypto.so.10)(64bit) for package: nrpe-2.15-2.el6.x86_64
--> Running transaction check
---> Package nagios-common.x86_64 0:3.5.1-1.el6 will be installed
---> Package nrpe.x86_64 0:2.15-2.el6 will be installed
--> Processing Dependency: libssl.so.10(libssl.so.10)(64bit) for package: nrpe-2.15-2.el6.x86_64
--> Processing Dependency: libcrypto.so.10(libcrypto.so.10)(64bit) for package: nrpe-2.15-2.el6.x86_64
--> Finished Dependency Resolution
Error: Package: nrpe-2.15-2.el6.x86_64 (epel)
Requires: libcrypto.so.10(libcrypto.so.10)(64bit)
Error: Package: nrpe-2.15-2.el6.x86_64 (epel)
Requires: libssl.so.10(libssl.so.10)(64bit)
You could try using --skip-broken to work around the problem

Usando el comando yum whatprovides libssl.so.10 se determinó que ambas liberias provenían del paquete openssl.

Como ya estaba instalado y el problema de las dependencias continuaba, se opta por actualizar a la última versión de openssl (bajando los paquetes desde redhat)

rpm -Uvh openssl-1.0.1e-37.el6.x86_64.rpm

Una vez actualizado openssl se puede instalar NRPE sin problemas:

yum install nrpe.x86_64
Loaded plugins: product-id, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package nrpe.x86_64 0:2.15-2.el6 will be installed
--> Processing Dependency: nagios-common for package: nrpe-2.15-2.el6.x86_64
--> Running transaction check
---> Package nagios-common.x86_64 0:3.5.1-1.el6 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

==============================================================================================================================
Package Arch Version Repository Size
==============================================================================================================================
Installing:
nrpe x86_64 2.15-2.el6 epel 224 k
Installing for dependencies:
nagios-common x86_64 3.5.1-1.el6 epel 17 k

Transaction Summary
==============================================================================================================================
Install 2 Package(s)

Total download size: 242 k
Installed size: 286 k
Is this ok [y/N]: y
Downloading Packages:
(1/2): nagios-common-3.5.1-1.el6.x86_64.rpm | 17 kB 00:00
(2/2): nrpe-2.15-2.el6.x86_64.rpm | 224 kB 00:00
------------------------------------------------------------------------------------------------------------------------------
Total 146 kB/s | 242 kB 00:01
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Warning: RPMDB altered outside of yum.
Installing : nagios-common-3.5.1-1.el6.x86_64 1/2
Installing : nrpe-2.15-2.el6.x86_64 2/2
Verifying : nrpe-2.15-2.el6.x86_64 1/2
Verifying : nagios-common-3.5.1-1.el6.x86_64 2/2

Installed:
nrpe.x86_64 0:2.15-2.el6

Dependency Installed:
nagios-common.x86_64 0:3.5.1-1.el6

Complete!