dijous, 17 de març de 2011

VLAN Access Control Lists (VACLs)

When you want to filter traffic that is moving from one VLAN to another, things are real CCNA-like and friendly :-)We use an Access Control List. In fact, we should elaborate on that term a bit now in light of this discussion. We actually use a Router-based Access Control List or RACL.
But what if we want to filter traffic that is flowing within a VLAN? On no, a Router-based Access Control List cannot help us! This is when we turn to the VLAN Access Control List. To help us understand this feature, let us create a topology and a sample scenario.
NOTA: es un recordatori, cal traduir i adaptar l'article.
Suposant que volem filtrar la VLAN 55, quan s'enrouta. En el switch que fa el IVR, apliquem la llista d'acces següent:


dijous, 10 de març de 2011

Configurar el Syslogd del MacOS X

Editar l'arxiu /etc/syslog.conf :
*.*                                       @
*.*                                       @
si no fem servir el port estandad, i reniciar el syslogd:

Per saber si esta en marxa i enviant els logs, podem injectar algo en el syslog:

i el el servidor de syslog hem de veure:

dimarts, 1 de març de 2011

Enabling High Performance Data Transfers

System Specific Notes for System Administrators (and Privileged Users)

These notes are intended to help users and system administrators maximize TCP/IP performance on their computer systems. They summarize all of the end-system (computer system) network tuning issues including a tutorial on TCP tuning, easy configuration checks for non-experts, and a repository of operating system specific instructions for getting the best possible network performance on these platforms
This material is currently under active revision. Please send any suggestions, additions or  corrections to us at nettune@psc.edu so we can keep the information here as up-to-date as possible.