What Is ARP? ARP stands for Address Resolution Protocol. It is a method of mapping a layer 3 protocol address to a layer 2 or hardware address. In most cases, ARP maps an IP address to an Ethernet MAC address. Something to be aware of is that ARP is used with IPv4. IPv6 uses the […]
What happens if you create a connection between two non-backbone OSPF areas that already connect to area 0? We sometimes call this a backdoor link. Connecting two non-backbone areas was covered in part 1. Will routes be shared between the two areas? Or will no routes be shared and traffic will travel via the backbone
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What happens if you connect two OSPF areas together when neither of them is area 0? Will routes be shared between the two areas, or will it simply not work? I can think of two scenarios for this: In this post, we’re going to lab the first scenario out and see what happens. We’ll look
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I recently came across an interesting issue with DHCP and Client Identifiers. Whilst working on the Junos as a DHCP server post, I found that only one client would get an address via DHCP, and the other client wouldn’t. The MAC addresses were different, so it appeared that it should be working. After some searching,
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BGP community strings are a way of marking or tagging a route. Routing policy can then match on a community string, and take a defined action. They are typically used in one of two ways: Types Of Community Strings Broadly speaking, there are three types of community strings. Standard communities are 4 bytes long and
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VRRP stands for Virtual Router Redundancy Protocol. It is used to create a Virtual IP (VIP) address, which can then be used as the default gateway for network clients or as a next hop for a static route. VRRP is one of several First Hop Redundancy Protocols (FHRP) and is similar to Cisco HSRP. The
What Is DHCP DHCP stands for Dynamic Host Configuration Protocol. It is a way to automatically give an IP address and related configuration details to an end device such as a laptop or smartphone. Why Is DHCP Used DHCP is used to ease the burden of administering IP addressing for end devices. Imagine a world
In this post, we are going to look at what MTU is. We’re also going to see what it looks like on the network with practical examples. What is MTU MTU stands for Maximum Transmission Unit and represents the largest frame or packet that can be sent over a link. We are typically concerned with
Does the vQFX support port mirroring? It certainly seems so! I couldn’t find a definitive answer to this in a quick search, so I decided to try it out and see what happens. The Setup Eve-NG is built as “bare metal” on a VM. Juniper vQFX – Junos 21.3R3 3 x Linux images within Eve-NG
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Network engineers plan, design, implement, operate and manage networks. That sounds great, but what does it mean? Let’s break it down and look at these in more detail. Please note that I group network engineer and network admin roles together. Others will associate network engineer roles with planning, design, and advanced support, and network admin
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