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Gratuitous ARP

We’ve talked about Traditional ARP, where a node is requesting another node’s MAC address. We’ve also talked about Proxy ARP, where a node is answering an ARP request on behalf of another node. Which brings us to another iteration of ARP known as Gratuitous ARP. A Gratuitous ARP is an ARP Response that was not prompted […]

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Proxy ARP

We’ve discussed the use cases and role of traditional ARP in the prior article of this series. In this article we will discuss Proxy ARP and its role and significance. Proxy ARP occurs when one node is responding to an ARP request on behalf of another node. Proxy ARP is not a malicious event, it […]

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Traditional ARP

As we’ve learned before, the Address Resolution Protocol (ARP) is the process by which a known L3 address is mapped to an unknown L2 address. The purpose for creating such a mapping is so a packet’s L2 header can be properly populated to deliver a packet to the next NIC in the path between two […]

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Routing Between VLANs

We wrote an article which covers Virtual Local Area Networks (VLANs) as a concept, and another article on configuring VLANs on Cisco witches. The remaining subject to cover is the different options that exist for routing between VLANs. Why do we need Routing Between VLANs? As we learned in a prior article, VLANs create a logical separation […]

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Configuring VLANs on Cisco Switches

We’ve before written about VLANs and what they can do as a concept. This article will focus on configuring VLANs on Cisco switches. We will look at each command necessary to configure the topology below. If this topology looks familiar, it is because you saw it in the article which described how VLANs operated on […]