A network protocol is a standard set of rules standard-standard, which specifies the method to send and receive data between multiple computers.
No single network protocol, and may coexist on the same computer multiple protocols installed, it is possible that a computer belonging to different networks.
This variety of protocols can be a security risk: each network protocol installed on a Windows system is available for all network adapters in the system, physical (network card or modem) or software (VPN adapters). If network devices or protocols are not properly configured, we can be giving unwanted access to our resources.
The simplest safety rule is to have installed the necessary number of protocols, both now and in most cases should suffice to only TCP / IP.
If we need more of a protocol, it is also advisable to disable it in each of the network devices that will not make use of it.
And finally, a Security Council contradicts the previous two: whether we need features that can be obtained with several protocols, or an extension of another protocol installed, you will often be preferable to install the two protocols. The typical example is to not use NetBIOS over TCP / IP and then install and use instead NetBeui if we need to share resources in a Windows network. The reasons are discussed below.
Finally, a clarification: a network connection between computers implies a relationship on many levels: we need a physical connection (cable, etc) need to manage the data carried, we need a transport system, we need to show the data. Network protocols typically work in groups, taking charge of partial aspects of communication
NetBEUI / NetBIOS
NetBIOS is a protocol for communication between computers that includes three services:
The name service allows computer name registration, applications and other identifiers on the network in general. A program can, through this service, determine which computer on the network carries a certain name.
The service enables sending packets and receiving packets on the network, point to point or broadcast.
The session service allows the establishment of connections between two points in the network and is similar to TCP.
This protocol corresponds to the pre-internet, 1985, and used on computers with win 98/95 and “Microsoft Windows for Workgroups.”
At that time, a network of internet was unimaginable dimensions, the model on which it worked was the segmented networks in clusters of a few teams (working groups) under the principle of trust: it was assumed that all computers each segment were safe.
Because of this design for small groups (optimally, a dozen, up about 200 teams) netbios is a non-routable protocol, each team is identified by a name (equipo_de_pepe, equipo_de_juan) and not a logical address, seeing each other only teams located in the same segment, and still require the use gateways (gateways) to connect the segments to each other, or with a host. In fact, despite its age and limitations, for small networks, the protocol is likely to remain faster.
Originally worked on the NetBios NetBEUI protocol that was responsible for data transport.
With the spread of internet, though, and the omipresencia TCP / IP, Microsoft operating systems allow you to run latest NetBios over TCP / IP, regardless of NetBEUI (in fact this protocol does not appear by default available on Windows XP).
Hence the paradox of safety tips that we said at first. In principle you do not need NetBios if you just want to connect to the internet. But if you should have NetBios (eg because you want to share a printer on a home network), you can run over TCP / IP, allowing you to dispense with the NetBEUI protocol, which is good, because it limits the number of protocols installed. But NetBeui not accessible from internet, not to be routable, it may be a major advantage to run NetBIOS over NetBEUI, disabling NetBIOS over TCP / IP.
NetBIOS uses ports 137, 138 and 139. You can find out if you have NetBIOS enabled from the console using the command netstat-an. If these ports are listening, NetBIOS over TCP / IP is installed.
Nbtstat program (also to be used in console mode) provides information on NetBIOS over TCP / IP.
NetBIOS is used mainly with the Client for Microsoft Networks service and File and Printer Sharing for Microsoft Networks, which allows access to other computer resources (folders, peripherals).
Eliminating NetBios protocol
Using the NetBIOS protocol over TCP / IP is not very good press, in terms of safety, because it makes visible to the internet presence of your computer, the computer name and user name, and is generally a possible route of attack . If your computer will be connected to Internet but not to a local network or going to share files or printers, you can remove it by removing the clients installed (either Client for Microsoft Networks or Microsoft Logon Family), and un-checking the box “I want to enable NetBIOS over TCP / IP.” And of course, if installed-NetBeui.
IPX / SPX
IPX / SPX is used for Novell NetWare networks, not necessary if you have a network of this type. The IPX protocol refers to the packaging of data, each packet including the destination address, which allows sending data from one network to another. The IPX protocol can not guarantee the integrity of the shipment (packet loss etc). It orders the SPX protocol.
While the IPX protocol is similar to IP, SPX is similar to TCP. Together, therefore, provide connection services similar to TCP / IP.
TCP / IP
They are a set of protocols, including two that give it its name: TCP and IP.
The IP protocol refers to how to split the data to send in blocks (packets, datagrams). As with IPX, IP is an unreliable service (or best), does not guarantee receipt of the package. The package could get damaged in another order with respect to other packages, or simply do not get doubled. The reliability is provided by the protocol of the transport layer, working in teams.
The IP protocol can carry data from one computer to another without need for a direct connection. Each packet carries including the address of the sender and recipient, so you can come to term moving through different networks, run by routers.
The TCP protocol is the one responsible for the transport of IP datagrams: the source computer is responsible for the creation of datagrams, their sequence, their identification, control errors and forthwith. On the target computer the same protocol is responsible for collecting TCP datagrams in sequential order, waiting for delayed datagrams, and to request the target computer that forwards those that were lost or have become damaged, being in charge at the end reconstructing the data with the received datagrams. The system is very flexible and effective: if a network connection between breaks, change the trajectory data and reach their destination by an alternative route: the network can take every package most suitable route available at that moment. Nor is it necessary that all packets arrive in the same order or at the same time. If a packet is lost, it is only necessary to forward this, not all of the data.