Think Again

Notes from Think Again MOOC. Definition of argument Interrupting, shouting, abusing doesn’t help to win the argument. Contradict (deny what the other say) is not an argument. An argument is a series of sentences, statements or propositions where some are premises (by order of reasoning) and one is the conclusion where the premises are… Read More »

Learn how to learn

Notes taken from the Coursera course Lean how to learn Focus mode – focused in a subject. no distractions Diffuse mode – not focused in a subject. jumping from one thing to another – creating new neuronal paths Spend less time but more focused Diffuse mode situations: Moment just before sleeping Doing sports Changing to… Read More »


DNS stands for Domain Name System Types of DNS servers: Authoritative server – The server has authoritative information about the queried domain and it will respond the request with the information in its local database. Not configured as a recursive resolver – The server will respond with a DNS Referral Response message to inform the client where… Read More »


Out of the box setup Network Port 1 / Internal interface – DHCP often enabled in port 1 / internal interface Change admin password Default username: admin / <blank> config system admin edit admin set password PASSWORD Switch modes Two available modes – need to be setup as a first step Interface – Each internal interface acts as… Read More »

Riverbed WAN Optimization

Introduction: WAN Optimization are useful on a high latency links (>200ms?). 60-90% data Steelhead devices are setup in-path. WAN Optimization techniques Compression at the TCP packet level Scalable Data Referencing – Data is stored on the local Steelhead with a pointer. If the remote Riverbed sees a block of data that has already been sent, it send… Read More »

Check Point Commands

Basic setup set expert-password set management interface eth1 set interface eth1 ipv4-address IP mask-lenght MASK set interface eth1 state on save-config Operating Reboot / shutdown expert> shutdown -h now reboot CPConfig – Reset SIC. Admin users. Enable functions. Cluster membership cpconfig Start and stop CP services cpstop cpstart Initial setup reconfiguration tool cpconfig FTP ftp IP… Read More »

Check Point Architecture

Technology Architecture Components SMART – Check Point Security Management Architecture Core systems: SmartConsole – Windows based GUI Security Management Server (SMS) (aka Smart Center Server) – Configuration and log storage Security Gateway – Security Device (SGW) Deployment modes Stand alone – Security Management Server + Security Gateway in the same device Distributed – Security Management… Read More »


MTU – Maximum transmission unit PMTUD – Path MTU Discovery Links have a maximum packet size limitation depending on the protocol/technology. MTU defines the maximum bytes of a packet on a link. With PMTUD, endpoints are capable of determine the MTU of a path. When a endpoint sends a packet larger than the MTU, this is fragmented on… Read More »

Google Hacking

Basic concepts “search a phrase” search anythin but -not -include -these -terms wildcard symbol * OR Operator |   Google URLs lr – search for specific language – lang_ca, lang_es &lr=lang_ca hl – changes the language of the google interface – ca, en, es &hl=en restrict – restrict search for country (domain or server location)… Read More »


Export saved sessions To move the saved sessions list to another computer, export the registry HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions and import it in the new computer. If no admin rights are available with the user, browse to the right user folder on the registry