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Network Tools


Firewalls


Misc


Protocols



    Address Resolution Protocol (ARP)


    Domain Name System (DNS)


    Dynamic Host Configuration Protocol (DHCP)


    File Transfer Protocol (FTP)

    • FTP is a standard network protocol used for the transfer of computer files between a client and server on a computer network.
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    • Commands
        binarySets the file transfer type to binary. Critical to the successful transfer of files such as Word documents, graphics, or software packages; also works fine with text files (files that contain only ascii text and no formatting).
        get $filenameTransfers a file from a remote computer to the computer you are typing on.
        mget $file1 $file2Transfers multiple files from a remote computer to the computer you are typing on.
        lsLists all the files in your current sub-directory.
        cdChanges the directory. To move back up to a previous level, use \"cd ..\" (note the space).
        put $filenameTransfers a file from the computer you are typing on to the remote computer.
        mput $file1 $file2Transfers multiple files from the computer you are typing on to the remote computer.
        pwdTells you the present working directory.
        <Ctrl>+hDeletes a character to the left of the cursor (acts as a backspace). Note: Use the Ctrl key; don't type the word "Ctrl".
        help $commandDisplays the definition of a command. Type \"help\" to see a full list of valid commands.
        byeEnds the FTP session.
    • External Links


    Hypertext Transfer Protocol (HTTP) / Hypertext Transfer Protocol Secure (HTTPS)


    Internet Message Access Protocol (IMAP)

    • IMAP is an Internet standard protocol used by e-mail clients to retrieve e-mail messages from a mail server over a TCP/IP connection.
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    • External Links


    Internet Protocol version 4 (IP) / Internet Protocol version 6 (IPv6)

    • IP is the principal communications protocol in the Internet protocol suite for relaying packets across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
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    • Subnets
        10.0.0.0/8Private
        127.0.0.0/32Loopback
        169.254/16DHCP link local address
        172.16.0.0/12Private
        192.168.0.0/16Private
        224.0.0.0/4Multicast
        240.0.0.0/4Reserved
        255.255.255.255/32Limited broadcast
        fc00::/7Unique Local Unicast
        fe80::/10Link Local Unicast
        ff00::/8Multicast
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    • External Links


    Lightweight Directory Access Protocol (LDAP)

    • LDAP is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services over an Internet Protocol (IP) network.
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    • Commands
        ldapbindUse ldapbind to authenticate to a directory server or find out if the server is running.
        ldapsearchUse ldapsearch to search for specific entries in a directory. ldapsearch opens a connection to a directory, authenticates the user performing the operation, searches for the specified entry, and prints the result in a format that the user specifies.
        ldapaddUse ldapadd to add entries to the directory. ldapadd opens a connection to the directory and authenticates the user. Then it opens the LDIF file supplied as an argument and adds, in succession, each entry in the file.
        ldapdeleteUse ldapdelete to remove leaf entries from a directory. ldapdelete opens a connection to a directory server and authenticates the user. Then it deletes specified entries.
        ldapmodifyUse ldapmodify to modify existing entries. ldapmodify opens a connection to the directory and authenticates the user. Then it opens the LDIF file supplied as an argument and modifies the LDAP entries specified by the file.
        ldapmoddnUse ldapmoddn to change the RDN of an entry or move an entry or subtree to another location in the directory
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    • External Links


    Network File System (NFS)

    • NFS is a distributed file system protocol allows a user on a client computer to access files over a computer network much like local storage is accessed.
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    • External Links


    Network Time Protocol (NTP)

    • Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.
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    • External Links


    Post Office Protocol version 3 (POP3)

    • POP is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a server in an Internet Protocol (IP) network.
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    • Commands
        USER Your user name for this mail server
        PASS Your password.
        QUITEnd your session.
        STATNumber and total size of all messages
        LIST Message# and size of message
        RETR $messageRetrieve selected message
        DELE $messageDelete selected message
        NOOPNo-op. Keeps you connection open.
        RSETReset the mailbox. Undelete deleted messages.
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    • External Links


    Real-time Transport Protocol (RTP)


    Secure Shell (SSH)

    • SNMP is used to communicate management information between the network management stations and the agents in the network elements.
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    • External Links


    Simple Mail Transfer Protocol (SMTP)

    • SMTP is an Internet standard for electronic mail (email) transmission. Some ways to deal with Spam.
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    • Commands
        ATRNAuthenticated TURN
        AUTHAuthentication
        BDATBinary data
        BURLRemote content
        DATAThe actual email message to be sent
        This command is terminated with a line that contains only a
        EHLOExtended HELO
        ETRNExtended turn
        EXPNExpand
        HELOIdentify yourself to the SMTP server.
        HELPShow available commands
        MAILSend mail from email account
        MAIL FROM: me@mydomain.com
        NOOPNo-op. Keeps you connection open.
        ONEXOne message transaction only
        QUITEnd session
        RCPTSend email to recipient
        RCPT TO: you@yourdomain.com
        RSETReset
        SAMLSend and mail
        SENDSend
        SOMLSend or mail
        STARTTLS
        SUBMITTERSMTP responsible submitter
        TURNTurn
        VERBVerbose
        VRFYVerify
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    • External Links


    Simple Network Management Protocol (SNMP)

    • SNMP is used to communicate management information between the network management stations and the agents in the network elements.
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    • External Links


    Spanning Tree Protocol (STP) / Rapid Spanning Tree Protocol (RSTP)

    • STP is a network protocol that builds a logical loop-free topology for Ethernet networks.
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    • External Links
      • IEEE 802.1D IEEE standard for local and metropolitan area networks--Media access control (MAC) Bridges (for STP and RSTP).
      • IEEE 802.1Q IEEE Standards for local and metropolitan area networks-—Virtual Bridged Local Area Networks (for MSTP).
      • Wireshark
      • wikipedia


    Transmission Control Protocol (TCP)


    User Datagram Protocol (UDP)

    • UDP allows computer applications to send messages to other hosts on an Internet Protocol (IP) network. UDP has no handshaking. UDP packets are dropped on congested networks. Therefore, it is unclear if the message is delivered.
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    • External Links



Proxies


Routers


Switches


Trojans, Viruses, and Worms

    Let's face it. If you use Microsoft products, then you will have to deal with trojans, viruses, and worms. Microsoft defenders state every operating system has them, which is true. However, the risk on a Linux operating system is relatively low. Linux has 863 threats as of Jan 1, 2006. Whereas Windows had 11,000 in the second half of 2005 alone.[1]