Configuring PAT with a pool of inside global addresses combines almost everything you can possibly configure with NAT in a Cisco router. Look at the requirements in this latest lab and put [...]
PAT – Port Address Translation – plays a huge role in IPv4 networks. Today’s post looks at the simpler of the two configuration options for router NAT configuration: a single router interface IP [...]
Dynamic NAT – specifically, dynamic NAT without also doing PAT – creates a 1-to-1 mapping between an inside local address and an inside global address. Unlike static NAT, however, dynamic NAT [...]
Static NAT matches a single inside local address with a single inside global address. It does not conserve addresses, but it does let you make a server reachable to external devices with a [...]
When first starting out with Cisco routers and switches, log messages are those irritating messages that show up to interrupt us from the current task at hand. Over time, most of us find those [...]
Most of us skim through descriptions of Syslog messages and message levels. This lab helps you slow down just a bit with a configuration exercise that makes you remember message severity levels [...]
Routers and switches issue log messages to tell us about different events. Be ready to run through the various options! Today’s lab exercises a couple of those options related to message formats [...]
NTP makes me think of old spy novels and movies, where the team would set their analog watches to the same time, and say something like “On my mark, it will be 9:55… mark!”. NTP uses other [...]
#CDP has long been the default and favored protocol for a variety of device discovery functions, but LLDP offers an alternative as well. (LLDP is new to the exam topics per the May 2016 new CCENT [...]
IP uses Address Resolution Protocol (ARP) to discover the MAC address used by other hosts in the same subnet. Unfortunately, cybersecurity attacks often use legitimate protocols in unintended [...]
Dynamic Host Configuration Protocol (DHCP), like many network protocols, can be used as part of a cybersecurity attack. DHCP Snooping, a LAN switch feature, monitors DHCP messages flowing through [...]
The Dynamic Host Configuration Protocol (DHCP) protocol allows DHCP Clients to lease an IP address from a DHCP server. Simple enough. However, the protocol itself is open to various cybersecurity [...]
The Cisco switch Port Security feature lets the switch monitor incoming frames, look at the source MAC address, and determine whether frames with that source address should or should not be [...]
Sometimes, #CCNA studiers get bogged down with port security, focusing on all those little optional configuration settings. But what of the main feature: securing the port? This latest lab [...]
Quick, can you name all the small options available with Cisco’s port security feature on Catalyst IOS images? Most of us can’t, unless we’re in the middle of studying for CCENT, [...]
Cisco’s Port Security feature just happens to be one of those switch features that can confuse people until they’ve configured and tested it a few times. One challenge comes from the fact that [...]
Are you comfortable matching packets with extended ACLs? How about with TCP and UDP ports in those ACLs? Here’s a 10-minute lab exercise to practice; all you need is the time and a piece of paper [...]
Ready to review how to match subnets with extended ACLs? And how to match well-known ports? Today’s lab lets you do just that. Along the way, you get to think about where to place the ACL to most [...]
Standard named ACLs follow a nice simple format, which is great for getting started with ACLs. This next lab gives you some exercise on the basic syntax, while throwing in a few issues related to [...]
Write a 1-line ACL to match something? Easy. Write a several line ACL with a bunch of requirements? A little harder. Choosing where to put that multi-line ACL, when the ACL requirements span [...]
First, think of TCP headers, and the source port and destination port. Then think about the predictable port – the well-known port – and whether it will be the source or destination port. Then [...]
#CCNA ACL questions can uncover your weaknesses even without a detailed and complicated list of requirements to place in a single ACL. In fact, my “Acing the CCNA Exam” live course on Safari [...]
