How to enable CUPS remote administration

CUPS (Common UNIX Printing System) is the standards-based, open source printing system developed by Apple Inc. for Mac OS X and other UNIX-like operating systems.

The default installation of CUPS only enable you to manage it from localhost computer. However, if you are interested in remotely administering CUPS, you need to grant access from other systems than just localhost to the CUPS administration.

To do so, edit the /etc/cups/cupsd.conf and have it explicitly grant access to the systems you want. as for example, to grant access to the system with IP address of 10.0.0.1:

All come back to IP address

We normally use domain name in accessing a homepage like:

http://www.yahoo.com

However, if your computer is accessing to the Internet directly without using a proxy server, it will need to first resolve this domain name (in this case www.yahoo.com) into IP address before it will try to get data from the website.

As for this example, if you look up the IP address for www.yahoo.com, you will get information such as:

C:\nslookup
Default Server:  dns3.maxonline.com.sg
Address:  202.156.1.58:53

> www.yahoo.com
Server:  dns3.maxonline.com.sg
Address:  202.156.1.58:53

Name:    www.yahoo-ht3.akadns.net
Address:  209.131.36.158
Aliases:  www.yahoo.com

How to configure Cisco Devices to Use a Syslog Server

syslog is a client/server protocol standard uses for forwarding log messages in an IP network. It is typically used for computer system management and security auditing.

Most Cisco devices can use the syslog protocol to manage system logs and alerts. However Cisco devices does not have large internal storage space for storing its logs. There are two options available in Cisco devices in storing syslog:

1. By default, the most recent log messages are save in internal buffer. However, the buffer size is limited to few kilobytes. In this case, when the device is rebooted, these syslog messages are lost.
2. Cisco devices can also use a syslog protocol to send messages to an external device for storing. In this case, the storage size is limited only by the available disk space on the external syslog server.

Eth0 is not active at Linux Fedora Startup

Sometimes even though you have configure such that "Activate device when computer starts" for eth0 in Linux Fedora, it appears to do nothing - eth0 is not active at startup.

This maybe a bug with Fedora. One way to overcome this issue is to execute the following command:

chkconfig network on

This will enable the network service to be started on every time the machine boot.

Cisco IP Access List Logging

A Cisco IOS Access Control list (ACL) is used to define traffic. Once that "interesting" traffic is defined, some action can then be taken on that traffic.

Logging messages about packets permitted or denied by an IP access list is also available in Cisco IOS. Logging-enabled ACLs provide insight into traffic as it traverses the network or is dropped by network devices. Any packet that matches the access list will cause an informational logging message about the packet to be sent to the console.

You can monitor how many packets are being permitted or denied by a particular access list, including the source address of each packet.

To enable logging to all enabled destinations, configuring the following:

logging on

How to add static route to your Linux Fedora machine

To add a default route into your Linux box,

route add -net 0.0.0.0 netmask 0.0.0.0 gw 10.0.0.1

However, if you only execute this command, the route will disappears if you reboot your system.

So, what would be the best way to permanently add that route to your system?

You may add or edit the default gateway on /etc/sysconfig/network file, to make sure your default route setting is preserve after your system boot.

Configuration example on network file:

NETWORKING=yes
HOSTNAME=fedora.frontier.com
GATEWAY=10.0.0.1