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Pape O. Fall's Blog
Access-Lists are fundamentals to today’s network as they provide basic packet filtering at the interface level. The router basically inspects each incoming or outgoing packet to determine whether to forward it or drop it per the configuration of the ACL (Access-List). While one of the many reasons to leverage the use of ACLs in today’s [ Read More ]
An Offset List is routinely used to control path selection by influencing routing metrics of learned routes of either EIGRP or RIP. It is important to note that Offset List are only used with Distance Vector Protocol which means that we can not use it with OSPF as it is a Link State protocol. It [ Read More ]
Prefix lists are typically used in route-maps or packet filtering as they represent an alternative to access-lists. However, prefix-lists in comparison with access-lists allow us to match prefixes at a much more granular level. A prefix is a portion of an IP address, starting from the far left bit of the far left octet. So, [ Read More ]
A distribute-list is typically used to filter routing updates either inbound or outbound from a router perspectives usually running some form of dynamic routing protocol. Even though there is the keyword “distribute”, this is not to be confused with route distribution. Again, I think the choice of the terms here could have been better but that’s my [ Read More ]
Conventional network security often focuses more on ACLs blocking traffic either inbound or outbound but Cisco switches do have the capability to secure switchports for inbound traffic by pinpointing and limiting ingress packets based on source Ethernet Mac Addresses. This is huge as now we can control at an even more granular level who gets [ Read More ]
The term “Storm” in Networking refers to packets flooding a specific broadcast domain which ultimately results in poor network performance. Cisco came up with a solution to mitigate such detrimental scenarios and it’s called “Storm Control” sometimes referred to as “Traffic Suppression”. As the name implies, it basically monitors incoming traffic levels every second and compare it with a [ Read More ]
The archive feature in Cisco IOS provides an automation mechanism in terms of saving configuration files either locally on the box or to a remote location. This is extremely useful in a corporate environment with many Network Engineers onsite. There could be times where unplanned downtime occurs and the inspection of the running config for any [ Read More ]
Route Maps are characterized as one of the most powerful tool in Cisco IOS toolkit and the reason for it is because they can do a large number of things for us. If you are familiar with the “IF then ELSE” statements in Programming Language then understanding Route Maps will be a breeze for you. IF a [ Read More ]
Cisco Embedded Event Manager (EEM) is a scripting and automation mechanism within the IOS that triggers specific actions in response to network events. It is a flexible and robust tool which can provide scalable solution to given scenarios. It is composed with 2 pieces: -Applets which a collection of CLI commands -Scripting which are defined using [ Read More ]
NTP is a protocol designed to basically time synchronize network devices across Local or Wide Area Networks. You would probably guess how critical this is in terms of troubleshooting as it would greatly assist in pinpointing time events and help isolate the root cause of a problem. On top of that, certain network devices need [ Read More ]
Hi, I'm Pape ! Folks call me Pop. I'm CCIE #48357. I love what I do and enjoy making tech easier to understand. I also love writing, so I’m sharing my blog with you