The process of maintaining the routing information may generate errors if there is no quick and accurate convergence between the routers. In design of complex networks may occur routing loops or loops. Routers transmit constant updates to their neighbors, if a router B receives an update of a network that has fallen, this forward this information to all its neighbors including the router B who first informed him of novelty, turn the router B will report that the network has fallen into router to form an endless loop. Read the rest of this entry »
Dec
22
The different types of networks generally have the following points in common:
Servers: Computers that provide shared resources to users through a network server
Clients: computers that access the shared resources provided by a network server
Support Connection: determines how computers are connected together.
Shared data: accessible files on network servers
Printers and other shared devices: files, printers or other items used by network users
Miscellaneous resources: other resources provided by the server
Dec
18
Ping is a diagnostic tool of TCP / IP, which provides useful information on the presence of another computer network, and on the performance of the connection, much like the sonar of a submarine (hence its name) sends a signal to a network computer and listen to the echo.
Although it is a very useful tool, its results can sometimes be altered by security policies set in the computer investigation, because sometimes, to make invisible to a network computer (undetectable) are configured to not answer this such requests. So if you’re making no response to ping a computer on your network, one of the issues to be considered is the existence of filters at the router, or firewall.
- Ping your local address 127.0.0.1; must respond. If no response, possibly the TCP / IP is damaged. We will have to reinstall the protocol.
- Ping your private IP, if you are in sub network (eg 192.168.1.2). Must respond. If no answer, or you misspelled your ip, or as in the previous case is a problem in the TCP / IP. You can determine your IP with ipconfig
- Ping the private IP gateway. Must respond.
- Ping the public IP gateway. It must respond.
- Ping the IP of a computer outside the network. It must respond.
- Ping the domain name of a computer outside the network. Must respond. Failure to respond (and if in the previous cases), you should check your DNS.
Dec
8
The router gives us the possibility of aid because it is difficult to memorize all available commands, the question mark (?), And the Keyboard tab give us the necessary assistance to that effect. The full tab not remembers the commands complete or do not want to write in full.
The? Placed immediately after a command that shows all start with those letters, placed after a space (spacebar +?) We list all the commands that can run in that position. Read the rest of this entry »
Dec
5
When you first start a Cisco router, there is some initial configuration. The router software will ask for a minimum set of details through a dialogue called optional setup. Startup routines Cisco IOS software are designed to initialize the router operations.
For this, the start-up routines should do the following:
• Make sure the router has verified hardware (POST).
• Locate and load the Cisco IOS software that uses the router for your operating system.
• Locate and apply the setup instructions for the specific attributes of the router, the protocol functions and interface addresses. Read the rest of this entry »
Dec
2
For the initial configuration of the router using the console port connected to a console or rollover cable and RJ-45 to DB-9 COM1 port to connect to the computer. This must have terminal emulation software such as HyperTerminal.
The configuration parameters are:
• The appropriate COM port
• 9600 baud
* 8 data bits
• No parity
• 1 stop bit
• No flow control Read the rest of this entry »