Posts Tagged ‘redundancy’

Stacking the Dell MXL Blade Switch

Friday, April 5th, 2013

Dell MXL blade switch

Dell MXL blade switch

The Data Center Bridging (DCB) enabled Dell MXL blade switch provides a 1/10/40GbE upstream solution for the Dell PowerEdge M1000e chassis. It comes with two fixed 40 GbE ports but is scalable up to six 40GbE ports via 40GbE FlexIO modules; this provides a total of twenty four 10GbE ports from a single blade switch using breakout cables. Other FlexIO modules available for the two FlexIO ports are a 4 port 10GbaseT module and a 4 port 10GbE SFP+ module. One Dell MXL switch can provide up to 32 line-rate 10GbE internal-facing ports for Dell blade servers. Additionally, using the 40GbE ports, 6 MXL blade switches can be stacked together. In this blog I will demonstrate how to stack 2 Dell MXL blades together. (more…)

Twitt

Multi-Area OSPF – Redundancy, Route Summarization, and LSA Filtering

Monday, July 9th, 2012

In this lab, all routers except for R4 and R5 are Cisco 3725 routers [IOS 12.4(15)T10]. Routers R4 and R5 are Cisco 7200 routers [IOS 12.4(24)T]. Below is the network diagram for this lab.
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Twitt

Single/Dual and Multihomed Connections

Monday, March 12th, 2012

Network engineers will sometimes speak of connections to their ISP(s) in terms of single homed, dual homed, single multihomed, and dual multihomed. Here is a breakdown and clarification of what this terminology means:

- Single Homed (1 link per ISP, 1 ISP)
- Dual Homed (2+ links per ISP, 1 ISP)
- Single Multihomed (1 link per ISP, 2+ ISPs)
- Dual Multihomed (2+ links per ISP, 2+ ISPs)

(more…)

Twitt

Default STP Behavior on Cisco Switches

Tuesday, January 31st, 2012

In a prior blog, Functionality of Layer 2 Switches/Bridges, I discussed the core functionality of layer 2 switches. In this blog, I hit upon the Spanning Tree Protocol (STP) used on layer 2 switches to prevent loops. As mentioned before, loops can be created via layer 2 switches by using more than one link to connect to the same switches. This is often done for redundancy purposes but is not possible without STP. (more…)

Twitt