Aruba Switching

10 . IP Routing Part 3

Route Types and Administrative Distance Connected and Local Entries Connected: the subnet is physically connected to the switch and there is no need for a next hop device Local: the subnet is configured inside the switch. This could be a loopback interface or Switch Virtual Interface (SVI). Static Routes You need a static route when the destination network is not…

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Aruba Switching

9. IP Routing Part 2

Subnetting IPv4 Address Classes The IPv4 address space is divided into 5 classes (A to E) each of which is designed for a particular purpose. Class A: the first octet is between 0 and 127. The first octet (8 bits) is reserved for the network ID which means 3 octets (24 bits) are available for hosts on the network Class…

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8. VRRP (Virtual Router Redundancy Protocol)

An endpoint may only have one DG (Default Gateway), and a single DG means a single point of failure. In this example, if Core-1 is the DG for PC-1 and Core-1 fails, PC-1 and any other endpoints using Core-1 as the DG will be isolated. You could add another DG for redundancy, but you would have to somehow change the…

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Aruba Switching, Technology

7. IPv4 Routing Part 1

Routing IP routing connects VLANs together and routes packets between them. Routing devices use Layer 3 packet analysis to forward L3 packets. Layer 2 switches forward frames among devices in the same LAN by processing Layer 2 headers.  This is based on destination MAC addresses. Layer 3 devices move packets between LANs based on Layer 3 IP addresses. Routing Layer…

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Aruba Switching, Technology

6. Link Aggregation

Link Aggregation Without link aggregation, if you used two links to connect two switches together, the two links would create a loop and STP would automatically block one of the ports. Link Aggregation fixes this issue by bundling multiple physical interfaces into a single logical interface. Since STP sees this as a single interface there is no blocking.    …

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5. Spanning-Tree Protocol

Redundancy In the above example on the left, if Core 1 fails then the network is down and client A won’t be able to communicate with client B. In the example on the right, if Core 1 fails the network will say up as Core 2 is available and the Client can communicate through this. While this mitigates a single…

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4. VLANS

VLANS VLANs are used to isolate endpoints so you have better control over the traffic Default VLAN is VLAN 1 Devices in the same VLAN can communicate without routing.   Collison Domains On a Layer 1 Hub, only one ethernet host on a particular segment may transmit at a time, otherwise there is a collision. This is controlled by an…

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