This scenario is made in GNS3 to practice BGP concepts and configurations: Local Preference, MED, Weight, AS Prepending, BGP Community, Aggregation, Route Reflectors and etc.
This scenario is made in the GNS3 to practice MP-BGP/ MPLS L3 VPN. In this scenario customer A has 1 headquarter office and 2 remote sites and they want to connect their remote sites to the HQ office. Customer B and C also want to connect their networks together.
Virtual Device Context (VDC) partitions a single physical device into multiple logical devices that provide fault isolation, management isolation, address allocation isolation, service differentiation domains, and adaptive resource management. VDC also virtualizes the control plane, which includes all those software functions that are processed by the CPU on the active supervisor module.
Enhancements required for a successful Unified Fabric implementation, where network and storage traffic are carried over the same Ethernet links, are defined under the Data Center Bridging standards defined by the IEEE.
These enhancements make sure that Unified Ethernet fabric provides lossless, no-drop, in-order delivery of packets end-to-end.
This is also called Converged Enhanced Ethernet (CEE).
These enhancements include:
Fibre Channel, or FC, is a high-speed network technology (commonly running at 1, 2, 4, 8, 16, and 32 gigabit per second rates) primarily used to connect computer data storage to servers. Fibre Channel is primarily used in storage area networks (SAN) in enterprise storage. Fibre Channel networks are known as a fabric because they operate in unison as one big switch. Fibre Channel mainly runs on optical fiber cables within and between data centers.
We had a Cisco 5508 Wireless LAN Controller in our HQ building which was managing 26 Aironet 3501I access points. It was running controller software version 7.4.110 with 50 AP base-licenses.
We decided to add 20 more APs in order to improve the wireless coverage. So we got new Aironet 3702I access points.
According to Cisco Wireless Solutions Software Compatibility Matrix controller software version 7.4.110 does not support the 3702I access points. So we had to upgrade the controller software.
You will see a log message like this in case the controller software does not support the more recent access points: “Discarding primary discovery request in LWAPP from AP xx:xx:xx:xx:xx:xx supporting CAPWAP”
We downloaded the most recent version of software (18.104.22.168 at the time of writing this post) and downloaded it to the controller. We rebooted the controller and licenses were gone!
We tried to re-install the license backup file we had made before upgrading but it FAILED!
We switched back to the previous software version immediately and rebooted the controller. The Licenses were back then.
We guessed that it was because we had made a major upgrade (from version 7.4.x. to 8.2.x) so we decided to upgraded to the very first version of controller software where Aironet 3702I APs were supported for the first time. We upgraded to controller software version 7.6.110 and this time it was successful.
I don’t know if Cisco guys approve this workaround but it worked for us.
This document defines up to 13 classes of traffic. A brief table of these classes and their respective markings, mappings and different queuing systems is given.
DS field in the IPv4/IPv6 headers replaced the IPv4 TOS field. (IETF RFC 2474)
Class Selectors in the DS field -> backward compatibility with the IP precedence in TOS field
PHBs -> define the packet-forwarding properties associated with a class of traffic
Expedited Forwarding (EF) PHB -> low-loss, low-latency traffic, low jitter, assured bandwidth
Assured Forwarding (AF) PHB -> gives assurance of delivery under prescribed conditions
QoS is a set of techniques to manage bandwidth, delay, jitter, and packets loss for flows in a network. The Internet Engineering Task Force (IETF) defines two major models for QoS on IP-based networks: Integrated Services (Intserv) and Differentiated Services (Diffserv).
The Intserv model integrates resource reservation and traffic control mechanisms to support special handling of individual traffic flows. The Diffserv model uses traffic control to support special handling of aggregated traffic flows.
The Cisco Nexus Series switches are modular and fixed port network switches designed for the data center (https://en.wikipedia.org/wiki/Cisco_Nexus_switches).
|Fabric Extender||Standalone||Blade Switch
|Performance||88 ~ 1440 Gbps||480Gbps ~ 6.4 Tbps||400 Gbps||1.4 ~ 7.68 Tbps|
|10G Density||~ 48||32 ~256||14 + 6 Uplink||48 ~ 384|
|40GDensity||–||~ 64||–||~ 96|
|100G Density||–||~ 32||–||~ 32|
|FEX Support||–||–||–||Up to 48 (L2/L3)|
|Programmability||?||OpenFlow||?||Python, TCL, OpenFlow, NX-API|
|6001 / 6004||7000 / 7700||9200 / 9300||9500|
|Standalone||Standalone||Standalone/ ACI Leaf
|Rack Impl.||TOR/EOR||EOR||TOR / Aggregation||EOR|
|Performance||1.28 / 7.68 Tbps||1.92 ~ 83 Tbps||1.44 ~ 6.08||15 ~ 60 Tbps|
|10G Density||48 / 384||96 ~ 768||~ 144||~ 2304|
|40GDensity||4 / 96||24 ~ 384||~ 36||~ 576|
|100G Density||–||12 ~ 192||~ 36||~ 128|
|FEX Support||Up to 48||32 / 64||– / ~ 16||Yes|
|FCoE||Yes||Yes||– / Yes||?|
|Programmability||?||?/ Python, TCL, OpenFlow, OnePK||Python , Puppet, Chef, Ansible, NX-API||Python , Puppet, Chef, Ansible, NX-API|
The first script is used to configure 61 Cisco Catalyst 2960S access switches for DHCP Snooping in a way that every switch builds the DHCP Snooping database with its own hostname on the FTP server so that different databases do not overwrite each other.