Archive for the ‘Force10 Networks’ Category

Connecting Dell PowerEdge M I/O Aggregator with Dell Force10 S4810 and Cisco Nexus 5548UP

Monday, February 11th, 2013

Dell PowerEdge M I/O AggregatorThe Dell PowerEdge M I//O Aggregator is a slick blade switch that plugs into the Dell PowerEdge M1000e chassis and requires barely any configuration/networking knowledge. Think of it as an advanced layer 2 switch that provides expandable uplink connectivity. The base blade comes with 2 x 40 GbE ports that by default are configured as 8 x 10 GbE ports. If desired, these ports can also be used as 40 GbE stacking ports. The Dell PowerEdge M I/O Aggregator also provide 32 internal 10 GbE connections for Dell blade servers you can install in the Dell PowerEdge M1000e chassis. If quarter-height blade servers are used, the M1000e can support up to 32 servers. This is pretty cool, not only in terms of functionality, but also in terms of the consolidation and the mess of Ethernet/power cables avoided by not using standalone components. (more…)

Twitt

Understanding and Implementing Flow Control on Dell Force10 Switches

Monday, January 28th, 2013

Ethernet flow control allows for a receiving node to temporarily stop the transmission of data from the sending node. As defined by IEEE 802.3x this is accomplished via the PAUSE frame. (more…)

Twitt

Distributed Core Network Architecture

Friday, January 18th, 2013

There is no doubt you have probably heard by now the importance of supporting ‘east-west’ traffic flow in large data center networks. So why is this and what does it mean? And when Gartner claims that 80 percent of data center network traffic now travels from server-to-server, just what impact does this have on network design/architecture? (more…)

Twitt

Dell Force10 – Layer 2 Multipathing via Virtual Link Trunking (VLT)

Tuesday, December 18th, 2012

In this blog I use one Dell Force10 S50N [FTOS 8.4.2.7] and three Dell Force10 S4810 switches [FTOS 8.3.12.1] to demonstrate Dell Force10′s layer 2 mulipathing technology called Virtual Link Trunking (VLT). With VLT, you can create a LAG for a server, switch, or any device that supports LACP to two different upstream switches.

Traditionally, a LAG from an access switch or server could only connect to a single upstream switch. For redundanacy purposes, many users would implement stacking on the upstream switches and then use a port-channel/LAG up to the stacked switch now seen as one logical entity. However, stacking is not the preferred solution here. Two main reasons for this is that stacking provides a single control plane mechanism that is managed by the master switch; there is no hitless failover. Compare this to VLT which provides a dual control plane mechanism and is hitless in nature. Additionally, when upgrading the switch firmware, the entire stack would need to be brought down. With VLT, one switch can be upgraded at a time without bringing down the other switch.

Stacking is more seen at the ToR or access layer. The ToR switches are usually stacked and VLT is then used upstream to the aggregate and core switches. However, if the ToR switch supports VLT such as the S4810 does, VLT can also be used from the switch down to the server. 1 GbE switches like the Dell S50N and Dell S60 do not support VLT, so, in these cases, stacking can still be employed.

In the least recommended approach, if no VLT or stacking is used at the aggregate layer connecting to the ToR on a layer 2 network, spanning tree protocol (STP) would need to be employed to block redundant links. This would create link and switch level redundancy. The issue with this is that you lose half the ports/bandwidth on the switch. By leveraging VLT, you can have an active-active multi-path connection from an access server/switch to two upstream switches seen as one logical entity employing a dual control plane mechanism. No putting-up with STP or blocked ports! (more…)

Twitt

Multi-Area OSPF in a Mixed Cisco and Dell Force10 Environment

Tuesday, November 20th, 2012

In this lab I use one Cisco 2621XM [IOS 12.4(2)T], one Cisco 2621 [IOS 12.3(18)], one Cisco 3660 [IOS 12.1(1)T], one Cisco 3640 [IOS 12.1(2)T], one Cisco 3550-24PWR-SMI [IOS 12.2(44)SE6], one Dell Force10 S60 [FTOS 8.3.3.7], and one Dell Force10 S50N [FTOS 8.4.2.6] to demonstrate multi-area OSPF in a mixed environment of Cisco and Dell Force10 switches. Below is a diagram of my lab setup. (more…)

Twitt

Blocking Hackers From Accessing Your Switch via Telnet/SSH

Sunday, October 21st, 2012

It’s amazing how much rattling at the doors and attempted intrusions companies become accustomed to seeing on their networks. Here I show a simple way to block telnet/SSH access to your switch. First, you should never use telnet to manage your switch over the Internet because the traffic is sent unencrypted and it is therefore insecure; SSH is the better option. Perhaps you only want to manage the switch from an internal network or only want to allow or block some hosts from using telnet/ssh. Below, I block all telnet/ssh access to the switch. I’m using a Dell Force10 S50N switch [FTOS 8.4.2.6]. (more…)

Twitt

Trunking and DHCP Across Dell Force10 Switches

Tuesday, October 16th, 2012

I did this lab some time back and thought it would be useful to post. In this lab I use a Dell Force10 S25P (FTOS 8.4.2.6) switch and Dell Force10 S50N (FTOS 8.4.2.6) switch to demonstrate trunking and Dynamic Host Configuration Protocol (DHCP) for multiple subnets. Both of these switches are layer 2/3 switches, however, I use the S25P to do all the routing and use the S50N strictly as a layer 2 switch. (more…)

Twitt

Advanced Private VLAN Configuration on Dell Force10 Switches

Tuesday, July 17th, 2012

In a prior lab, “Dell Force10 Z9000 – Creating Additional Layer 2 Isolation via Private VLANs“, I demonstrated some basics in regards to private VLANs. In this lab, I plan to go a little further and demonstrate how hosts in the same private VLANs (PVLANs) on two different switches can communicate with each other. (more…)

Twitt

Dell Force10 Z9000 – Creating Additional Layer 2 Isolation via Private VLANs

Saturday, July 7th, 2012

Private VLANs provide additional segregation capabilities within a VLAN. A private VLAN provides further layer 2 isolation between ports. A common example of private VLAN use is a hotel providing Internet access for patrons while at the same time preventing direct access between guest ports. Instead of using private VLANs, you can create a separate VLAN and assign a separate IP subnet to each guest as shown below. (more…)

Twitt

802.1Q Trunking Between Cisco and Dell Force10 Switches

Monday, July 2nd, 2012

VOIP PhonesIn this lab I use a Dell Force10 S25P switch [FTOS 8.4.2.6] and a Cisco C3750 switch [IOS 12.2(25)SEE3] to demonstrate 802.1Q trunking. (more…)

Twitt