Some of the best Useful Linux commands

Useful commands for the Linux command line This short guide shows some important commands for your daily work on the Linux command line. arch Outputs the processor architecture. $ arch i686 cat Outputs the contents of a file. $ cat lorem.txt Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut(…)

Checklist for SQL mail configuration

You must have a mail client (such as Microsoft Outlook) installed on the computer that runs SQL Server. Use the Corporate or Workgroup option for Microsoft Outlook 2000 (Microsoft Outlook 2002 does not have the Corporate or Workgroup option). To select the option, on the Tools menu, click Options, and then double-click the Mail Services(…)

How to configure or edit the connection timeout setting on the PIX/ASA

In order to change the global timeout setting for all connection with the CLI, refer to this command: asa(config)#timeout conn 01:00:00 This command can also change default timeout for several other connections, for example: xlate | conn | udp | icmp | rpc | h225 | h323 | mgcp | mgcp-pat | sip | sip-disconnect(…)

How to configure policy nat on ASA 5520

To gain access from one internal segment to the Demilitarized Zone (DMZ ), configure the Adaptive Security Appliance (ASA) for natting. To preserve the packet and assure that natting is bypassed, a no nat statement with an Access Control List (ACL) must be configured. This is performed when the administrator does not want natting to(…)

How to configure the PIX / ASA packet capture feature

The PIX/ASA can be configured in order to capture packet information like a sniffer that can be later viewed. There are two ways to do this. In order to capture the packets and later download them to view in ethereal (pcap format), complete these steps: Create an access-list in order to match the traffic. Apply(…)

How to create a new user in the Adaptive Security Appliance (ASA)

In order to create a user in the ASA, use the username command in global configuration mode. For example: hostname(config)#username password privilege In order to include or exclude user authentication for traffic through the ASA, use the aaa authentication commands with the include or exclude keywords in global configuration mode.

How to configure the hairpinning feature on the PIX/ASA

With PIX/ASA version 7.0 and later, a new feature is introduced that allows the PIX to support hairpinning in a VPN environment. When the PIX/ASA is the hub in a VPN environment, this feature supports spoke-to-spoke VPN communications as it provides the ability for encrypted traffic to enter and leave the same interface. If the(…)

How to configure the PIX/ASA Firewall to block IM services

In many cases, it is necessary to block connectivity to Instant Messaging (IM) services, such as AOL Instant Messenger, Yahoo Instant Messenger, and ICQ. In order to accomplish this, block the ports that those clients use. Ports used by IM services are dynamic. You can block the IP addresses and the port numbers used by(…)

How to configure the PIX Firewall to pass traffic without NAT

There are the two ways to allow traffic to pass through the PIX Firewall without translating the source address: * Issue the no nat command. The nat (inside) 0 command allows traffic to pass from the inside to the outside without translating the source addresses, but this version of the nat 0 command(…)

How to configure the PIX Firewall to allow traceroutes through it

The PIX Firewall does not support the initiation of the traceroute command as it is not part of the PIX command set. However, it can be configured to allow traceroute through it. When a traceroute command is issued from the outside, the PIX does not display its own interface IP address nor does it display(…)