Posts Tagged ‘ethernet’

Missing VLANs are not automatically created in NX-OS

Wednesday, February 17th, 2010

In IOS, if we assign a switchport to a non-existent VLAN, the switch will kindly create the missing VLAN for us. NX-OS does not do that – if a switchport is assigned to a missing VLAN, the interface will be placed in the down state. Let’s look at it… (more…)

EtherChannel behavior in NX-OS

Tuesday, February 9th, 2010

I’ve had a lot of discussions with clients about the behavior of Port-Channel interfaces and their associated physical counterparts.  It’s necessary for many parameters of the physical and logical interfaces to be the same.  Here’s the behavior within NX-OS and the preferred way that I make changes to EtherChannels.

In this, we’re going to continue working with the logical interface Po100 and the physical interfaces Eth1/19 and Eth1/20 which will be in the EtherChannel. (more…)

The FEX information is cached until it’s re-assigned to a different FEX

Tuesday, February 2nd, 2010

Continuing our journey into the world of FEXs on the Nexus 5000 and 2000, today we’re going to look at the behavior of the FEX configs themselves on the Nexus 5000.

All of the configuration and software information (firmware/images) for the FEX (Nexus 2148T) are kept on the parent switch (a Nexus 5000-series switch). Going on this, what happens when the FEX goes offline? Do I lose my config?

A stack of 3750 switches can be provisioned ahead of time, so that as stack members are added (assuming that they’re the correct type/model), no changes must be made – just move on. What kind of behavior is available on the Nexus 5000/2000?

I haven’t found provisioning available yet for FEXs on the N5k, however I did notice that the configurations for the FEX are retained when the FEX goes offline and online. This is great — if the 2148T fails or the fabric interface links are disconnected, the config will still be there (although not visible until the FEX comes back online). This article is looking at it from an association perspective (N2148T association with the N5k, not a configuration (actual port configs on the FEX). With that said, let’s explore this further… (more…)

Introducing the Nexus 2148T (Fabric Extenders)

Friday, January 29th, 2010

The Nexus 5000-series (5010 and 5020) support the Nexus 2000-series of switches.  The Nexus 2000-series are fabric extenders (FEXs) – which is essentially a way to stretch out the N5k switch fabric.  Currently there’s only the Nexus 2148T switch, which we’ll cover (at least the basics) in this article.

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NX-OS – great interface range support

Friday, January 29th, 2010

(as I’ve been working with NX-OS as of late, I decided to jot down some thoughts and findings – this is one part in a series of posts on NX-OS)

Have you ever visited a friend’s house and said “I like what you’ve done with the place!”  Many of us have – in which case you should be able to relate to this post.  There are moments in working with NX-OS where I want to tell Cisco “I like what you’ve done with the place!”  This post is about just such a finding — the great support of interface ranges within NX-OS.

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JUNOS/Juniper EX-series Cheat Sheet

Monday, November 23rd, 2009

While studying for my JNCIA-EX certification, I compiled this short cheat-sheet.  While the EX-series of switches run JUNOS, there are additional features found on the EX-series than on other (J-series, M-series, etc.) platforms.

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