Month: January 2018

Datacenter Design II (Blades, Scaling, Bandwidth)

Blade Server design

Overleg with the server team connectivity.
Many blade servers enter de “enterprise switch” market with an integrated switch.
Pass-through cabling or integrated switches.
Significant impact on power – cooling – weight.

Connecting the blade to the network

If you use the integrated blade switch, use a layer3 access layer.
Avoid a double Layer 2 design:
- [Layer 2 on the access layer] connected to a [layer 2 domain within the bladeswitch].
If you use passthrough, use a layer2 or layer3 access layer.

Scaling the Datacenter Architecture

Datacenter Design I (Core, Aggregation, Access Designs)

Core

Not all datacenter designs needs a core layer
Access to aggregation, aggregation to core : 10 or 40GBps
CEF load balancing tuning (L3 + L4)
Core should run L3 only, Aggregation acts as L3/L2 boundry to access
Core runs OSPF / EIGRP with aggregation

Aggregration

Wan Services (Sonet, Metro, VPLS, MPLS)

SONET / SDH

Sonet ( Synchronous Optical Networking)

American National Standards Institute (ANSI)
Used in US / Canada
Synchronous transport signals (STS) used for speed

Synchronous Digital Hierarchy

International Telecommunications union (ITU)
Used everywhere expect US / Canada
Synchronoous transport Modules (STM) used for speed)

IP Subnetting Template

Location	Subnet	VLAN	Description	Prefix
				10.1.0.0/16
Location01	10.1.10.Y	10	Data
	10.1.20.Y	20	Voice
	10.1.30.Y	30	WiFi
	10.1.40.Y	40	Servers Printers
	10.1.50.y	50	Exit VLAN
	10.1.98.Y	98	Public WiFI
	10.1.99.Y	99	Management
				10.2.0.0/16
Location02	10.2.10.Y	10	Data
	10.2.20.Y	20	Voice
	10.2.30.Y	30	WiFi
	10.2.40.Y	40	Servers Printers
	10.2.50.y	50	Exit VLAN
	10.2.98.Y	98	Public WiFI
	10.2.99.Y	99	Management

Hierarchical Design – (Campus Core , Distribution, Access)

Routing Design Principles (EIGRP, OSPF, BGP)

EIGRP design principles

EIGRP works for arbitrary topologies for small to medium networks.
A flat EIGRP network doesn’t really scale beyond 400 routers and will lead to performance issuse
- How to solve this?
  - Stub areas, summerization, route filtering limits the query scope
If EIGRP doesn’t have a feasible successor it will query all it’s neighbours.
- “I don’t have a route anymore, don’t route through me, give me a viable route”.
BFD to optimize convergence (100ms wtih 1000 routes).
2 second hello timer, 6 second hold timer ( recommended )

Multiple EIGRP design principles

Used to merge two networks ( Acquisitions )
Different administrative groups in a company
a way to devide large networks ( and control queries )
Routes are distributed between AS ( don’t loop! )

PPDIOO