Showing posts from May, 2013
Installing NFS on CentOS 6.2 This is a how to install the NFS service on a Linux CentOS 6.2 box and making it accessible to others. The scenario is the following: Grant read-only access to the /home/public directory to all networks Grant read/write access to the /home/common directory to all networks  At the end of this guide you will get: A running NFS server with various LAN shared directories A active set of firewall rules allowing the access to NFS ports A permanently mounted NFS shared on a CentOS / Ubuntu client      I assume you already have: a fresh running Linux CentOS 6.2 server  a sudoer user, named bozz on this guide an accessible RPM repository / mirror a Linux client with CentOS / Ubuntu Steps Login as bozz user on the server Check if rpcbind is installed: $ rpm -q rpcbind rpcbind-0.2.0-8.el6.x86_64 if not, install it: $ sudo yum install rpcbind Install NFS-related packages: $ sudo yum install nfs-utils nfs-utils-lib O

How To Break Into A Cisco ASA If You Do Not Have The Enable Password

From time to time, I get a service call asking me to break into a Cisco router or an ASA or a PIX. In most cases, the device was deployed a long time ago and nobody remembers the password. Or they have a copy of the config but the password was stored in the encrypted format. If you have the password in encrypted format, you might luck out if it is a commonly-used value such as 8Ry2YjIyt7RRXU24 (password is blank) or 2KFQnbNIdI.2KYOU (password is “cisco”). You can try to brute force it with John the Ripper, or Cain and Abel, or some precomputed rainbow table. The time required to brute force a complex password will depend on the character set used in the password, the length of the password, and the speed of the computer that is running Cain & Abel. Might take an ice age to brute force it. Would it be worth the time? You might have better luck with a bit of lateral thinking. Just paste the encrypted password into Google and see if anyone has posted their own config

QOS Priority Levels

One of the most feared technologies by CCIE candidates is QOS (Quality of Service). This is understandably because most first world countries seldom have problems with bandwidth or getting more if needed. So the necessity for juggling traffic around, by means of QOS strategies is almost non existent. On the other hand, engineers in developing countries tend to be familiar with various QOS technologies, because of frequent bandwidth shortages as a result of the high bandwidth costs. Here is a concise table listing the all the values for both BYTE fields: TOS-BYTE = (3bits IP PREC + 5bits legacy) IP Precedence  Description IP PREC Binary (3 bits) IP PREC Decimal Value ROUTINE 000 0 PRIORITY 001 1 IMMEDIATE 010 2 FLASH 011 3 FLASHOVERRIDE 100 4 CRITICAL 101 5 INTERNETWORK CONTROL 110 6 NETWORK CONTROL 111 7 . DiffServ Field = (6bits DSCP + 2bits ECN) DSCP PHB Groups (8x + 2y) DSCP-Field Binary (6