The Internet Control Message Protocol (ICMP) is one of the core protocols of the Internet Protocol Suite. It is chiefly used by networked computers’ operating systems to send error messages—indicating, for instance, that a requested service is not available or that a host or router could not be reached. When creating Cisco IOS ACLs, many [...]

Setting Up the System Clock One of the most important tasks when setting the security appliance is to verify that the clock settings are accurate. The security appliances can timestamp the syslog messages using the system clock before sending them to the configured types if logging timestamp is enabled, as discussed in the “Enabling Logging” [...]

The show version command displays the PIX Firewall unit’s software version, operating time since last reboot, processor type, Flash memory type, interface boards, serial number (BIOS ID), activation key value, license type (R or UR), and timestamp for when the configuration was last modified. The serial number listed with the show version command in PIX [...]

The general way of checking status and statistics is to use a form of the user mode command show interfaces. Issuing the show interfaces command without any arguments will show information for every interface in a router. This produces more than a terminal screen of information for every interface in a router; this could be [...]

Memory, RAM, is one of those resources that is extremely valuable to IOS. Monitoring memory utilization can be done with the user mode commands show processes memory and show memory. Figure 5-16 shows part of the output from the show process memory command. qutter(config)# show processes memory ———————————————————— Allocs Allocated Frees Freed Process (bytes) (bytes) [...]

Use the user mode command show processes cpu to find out how busy the CPU is and what IOS processes are running gate1>show processes cpu CPU utilization for five seconds: 6%/4%; one minute: 8%; five minutes: 8% PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process 1 32 233 137 0.00% 0.00% 0.00% 0 Load [...]

We can check the contents of flash memory with the user mode command show flash. Figure 5-2 shows the output of the show flash command on our test router Dallas. Dallas>show flash System flash directory: File Length Name/status 1 8945732 c2500-js-l.113-5 [8945796 bytes used, 7831420 available, 16777216 total] 16384K bytes of processor board System flash [...]

Enter the copy command to perform these tasks: •Download a system image or configuration file from a TFTP or rcp server to a Flash device •Upload a system image or configuration file from a Flash device to a TFTP or rcp server •Configure the switch using a configuration file on a Flash device or on a [...]

To verify whether a soft reset is successful and check information about the routing table and about BGP neighbors, perform the following steps: Step 1 Enter the show ip bgp EXEC command to display entries in the BGP routing table. The following output shows that the peer supports the route refresh capability: Router# show ip bgp [...]

A router running Cisco IOS Release 12.0 or later does not select or use an iBGP route unless both of the following conditions are true: •The router has a route available to the next hop router: •The router has received synchronization via an IGP (unless IGP synchronization has been disabled). BGP bases its decision process [...]

Here are the steps to configuring AAA: Enable AAA Configure authentication, using RADIUS or TACACS+ Define the method lists for authentication Apply the method lists per line/ per interface It is important to note that Cisco IOS software attempts authentication with the next-listed authentication method only when there is no response from the previous method. [...]