Network broadcasts can create a huge amount of traffic on your organization’s network. When one device sends out a single broadcast, that broadcast goes to all devices on the subnet or VLAN. How can you manage these broadcasts to make your network more efficient? One method is to use Cisco Catalyst broadcast suppression — also […]
Storm Control for Switches in Cisco IOS Read More »
Welcome to our Cisco IOS Classic Interface Commands Cheat Sheet. You can see our other IOS cheat sheet here. You can view all our Cisco IOS How To’s here. Here are the most frequently used Interface commands as a quick reference/cheat sheet. This will help you remember the key interface configurations: Important show commands show
Cisco IOS Classic Interface Commands Cheat Sheet Read More »
The primary purpose of the show interfaces command is for displaying the equipped interfaces and their status. Here’s the information you can get about an interface from this command: Interface type Status Speed and duplex Encapsulation Errors on the interface The last time the interface flapped The last time the error counters were reset Utilization
Show Interfaces Command in Cisco IOS Read More »
The Show Environment command can be very helpful to alert you of potential hardware issues. You will need to access this command in global Exec mode. Here are the options available for the Show Environment command: show environment [alarms | all | fans | hardware | last | leds | power-supply | table | temperature
Show Environment Command in Cisco IOS Read More »
What is Policy-based Routing? With policy-based routing (which we will call PBR from here on out), you get the option to implement policies that selectively cause packets to take different paths. Additionally, PBR can mark packets so that certain types of traffic get prioritized. One example of PBR is, say that your OSPF routing protocol
Policy Based Routing feature Usage in Cisco IOS Read More »
Point-to-Point (PPP) Protocol is an excelent Layer 2 protocol used to establish a direct connection between two nodes. It can provide connection authentication, transmission encryption (using ECP, RFC 1968), and compression. PPP was designed somewhat after the original HDLC specifications. The designers of PPP included many additional features that had been seen only in proprietary
PPP Configuration in Cisco IOS Read More »
What happens if there is a system or user on a VLAN that is infected by malware or is deliberately running a scanning program? What if you have some public ports on your switches that you only want to have access to the Internet and not each other? This problem can be easily solved with
Protected Ports on Cisco Switches in Cisco IOS Read More »
If you want to partition flash memory of routers with flash, you can. On most class B Flash file systems, you can partition banks of Flash memory into separate, logical devices so that the router can hold and maintain two or more different software images. This partitioning allows you to write software into Flash memory
Partitioning Internal FLASH in Cisco IOS Read More »
This How To explains Passwords on Cisco platforms. The question you might ask is: Doesn’t the router already have default passwords? The answer is NO, it doesn’t. There is no automatic password defense that comes with your router. As a Cisco admin, this should be taken very seriously. It is so important and so easy
Passwords in Cisco IOS Read More »
OSPF (Open Shortest Path First) is an IGP (internal gateway protocol), and OSPF is an open standard protocol originally defined in RFC 2328. Since then OSPF has been updated numerous times including functionality to support IPv6 and Address Families. OSPF is supported on every major routing platform as well as Windows Server 2003 and Linux
OSPF Basics in Cisco IOS Read More »
Routine maintenance is the underpinning of any well run network. Through routine maintenance, consistency, predictability and standardization all result allowing the network to operate as expected and in times of fault, makes a better troubleshooting environment. As part of any routine maintenance activity, Cisco provides several commands to help. One less known command is the
Maintenance with the ‘show diag’ command in Cisco IOS Read More »
You can use the service timestamps command to create timestamps on the router’s log files. Since version 11.3, the Cisco IOS has enabled certain timestamps by default, so most of us have this on. However, there are additional timestamps options that you can enable as well as places where timestamps are probably off by default.
Service Timestamps in Logging in Cisco IOS Read More »
Whenever we teach our Hands-On courses, we always have a section of the course that discusses troubleshooting the network or technology the class is learning. A key part of troubleshooting any network is knowing the technology, no argument. But even the masters of technologies like Multicasting, or IP Networking, or MPLS, still can benefit from
Leveraging Logging for Troubleshooting Using Cisco IOS Read More »
More than 60% of all truck rolls for Service Providers are related to Wi-Fi and Wireless LAN issues. From poor bandwidth performance to interference, issues abound. We offer the industry best, hands on training for Field Technicians, Customer Support Representatives, and technical staff that will elevate their understanding and save you money! “This course
Wi-Fi and WLAN Skills that save money! Read More »
One of the most annoying things in Cisco IOS is its old roots in the 23 line terminals. Every 23 lines, you get a –More– pause, to which you have to hit the space bar to continue the output. Now maybe this does not bother you. Fine, move on to our next Cisco tip. But
Stopping and Changing the –More– Console Output Interrupt Read More »
