Cisco interface naming is straightforward. Individual interfaces are referred to by this convention: media type slot#/port# “Media type” refers to the type of media that the port is an interface for, such as Ethernet, Token Ring, FDDI, serial, etc. Slot numbers are only applicable for routers that provide slots into which you can install modules. [...]
To configure any feature of the router, you must enter configuration mode. This is the first sub-mode of the parent mode. In the parent mode, you issue the command config. Router#config Router(config)# As demonstrated above, the prompt changes to indicate the mode that you are now in. In connfiguration mode you can set options that [...]
When you first connect to the router and provide the password (if necessary), you enter EXEC mode, the first mode in which you can issue commands from the command-line. From here you can use such unprivileged commands as ping, telnet, and rlogin. You can also use some of the show commands to obtain information about [...]
You can use NTP to synchronize time on a variety of devices including networking equipment. I have included the necessary NTP commands for a variety of Cisco Systems products because it is one of the most popular manufacturers of networking equipment and would feature in the overall architectures of many home office/small office (SOHO) environments [...]
syslog is a standard for forwarding log messages in an IP network. The term “syslog” is often used for both the actual syslog protocol, as well as the application or library sending syslog messages .
Syslog is a client/server protocol: the syslog sender sends a small (less than 1KB) textual message to the syslog receiver. The receiver is commonly called “syslogd”, “syslog daemon” or “syslog server”. Syslog messages can be sent via UDP and/or TCP. The data is sent in cleartext; although not part of the syslog protocol itself, an SSL wrapper can be used to provide for a layer of encryption through SSL/TLS.
By default, the configuration includes a policy that matches all default application inspection traffic and applies inspection to the traffic on all interfaces (a global policy). Default application inspection traffic includes traffic to the default ports for each protocol. You can only apply one global policy, so if you want to alter the global policy, for example, to apply inspection to non-standard ports, or to add inspections that are not enabled by default, you need to either edit the default policy or disable it and apply a new one. For a list of all default ports
When filtering is enabled and a request for content is directed through the security appliance, the request is sent to the content server and to the filtering server at the same time. If the filtering server allows the connection, the security appliance forwards the response from the content server to the client that originated the request. If the filtering server denies the connection, the security appliance drops the response and sends a message or return code that indicates that the connection is not successful.
In computer networking, a Media Access Control address (MAC address) or Ethernet Hardware Address (EHA), hardware address, adapter address or physical address is a quasi-unique identifier assigned to most network adapters or network interface cards (NICs) by the manufacturer for identification. If assigned by the manufacturer, a MAC address usually encodes the manufacturer’s registered identification number.
To configure multiple switchports at the same time we use the interface range configuration command. Example: Switch(config)#interface range fastethernet0/1 – 20 Switch(config-if-range)#speed 100 Switch(config-if-range)#duplex full The previous example will hardcode the speed and duplex settings on switchports 1 to 20. But this could well have been assinging them all to the same vlan. We can [...]
In order to view the log of a Cisco router we have to enable logging. This is done using the following command global configuration command: logging buffered To view the log on the router we use the following command: show log
A terminal emulation program for TCP/IP networks such as the Internet. The Telnet program runs on your computer and connects your PC to a server on the network. You can then enter commands through the Telnet program and they will be executed as if you were entering them directly on the server console. This enables you to control the server and communicate with other servers on the network. To start a Telnet session, you must log in to a server by entering a valid username and password. Telnet is a common way to remotely control Web servers