Tag Archives: Cisco

Using putty instead of the default ssh from Cisco device manager


How do I configure Cisco DCNM so Putty starts when I select to go to the command line of a switch?

right click on switch

If you right click on a switch in the overview section in DCNM, you can go to the command line of that switch, but how do you change the default CLI SSH into Putty (or another telnet / SSH capable tool)?

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How to add new members to an existing Cisco smart zone

Cisco MDS

DCNM is down. I love the tool, but the downside is that you forget how to use the CLI. I faced downtime of our DCNM appliance and was forced to use the CLI instead. No big deal actually, but I still want to post the commands to use when you need to add new hosts to existing zones.

First you might want to create a new device alias for the new hosts:

device-alias database
device-alias name server1 pwwn 20:11:00:15:b9:00:00:00
device-alias name server2 pwwn 20:11:00:15:b9:00:00:01
device-alias commit

And then you want to add the new aliases to the existing (smart) zone:

zone name NameOfZone vsan 123
member device-alias server1 init
member device-alias server2 init
zone commit vsan 123

You don’t need to commit the whole zoneset again, since that one didn’t change. Check it by running:

zoneset activate name ZoneSetName vsan 123

That’s it! there’s not much to it, and can save you a lot of time as well!

Cisco MDS “fabric merge” and “switch add” prerequisites

Cisco MDS

Prerequisites when adding a new SAN switch to an existing SAN fabric

When using enhanced device aliases, make sure you enable this on the new switch as well:

device-alias mode enhanced
device-alias commit

You can verify if this is enabled on an existing switch by this command:

sh run | grep “device-alias mode”

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The EMC / Dell merger: my tears and thoughts

Dell EMC

It’s been a few weeks now since Mr Dell, Silver Lake and MSD Partners announced they want to take over EMC and with that become the world’s largest privately held IT company. For me I relived the whole HP / Compaq merger and at that time Compaq was my favorite company. My whole world collapsed. What was going to happen to the world I lived in? It was going to disappear! But luckily it did not. The best pieces of Compaq at the time, their servers, were simply rebranded and sold as HP Proliants and the Alpha CPU “suddenly” appeared as the Itanium from Intel. And everybody was happy. Well, sort of. At least the server department kept on delivering what they were famous for.

And now this happened

I never realized Michael Dell was even in a position to actually raise that kind of money. But with help from Silver Lake and MSD Partners he succeeded to raise sixty five Billion US Dollars! Just imagine! Oh, wouldn’t I like to get my hands on a small portion of that!! But that’s a whole other story. Forget the money, forget the stock exchange market: what will this mean for both companies and the people working there? As some of you know, I’m involved with both the EMC education department as well as the customer facing piece of EMC Support and I want to share my thoughts on the future of my current “Compaq” equivalent, aka “EMC”.

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Cisco Smart zoning – part II: examples

Smart zoning examples

In my smart zoning post from last February I already presented the way to get started with Cisco smart zoning. I initially planned to give a more detailed calculation on how much time you can save if you were using smart zoning compared to SIST zoning.

SAN fabric

I was talking to an EMC SAN instructor (Richard Butler) this week and after I did a little white boarding and used my hands to picture how massive a traditional SIST zone environment would be, we agreed smart zoning is the way to go.

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Adding or replacing a Cisco SAN switch in an IVR topology

Cisco MDS

If you have multiple datacenters or a multi tenant fibre channel environment and you’re using Cisco FC switches, it’s a best practice to use VSANs to separate the configurations of each location / tenant. To allow storage arrays and / or hosts in different VSANs to communicate with each other Inter VSAN Routing needs to be used.

If you need to have 2 EMC VNX storage arrays “talk” to each other for MirrorView for example over 2 or more datacenters (for data replication purposes that is) or hosts in one DC talk to storage in another DC, using transit VSANs (and therefore IVR) will keep your VSANs with equipment indoors and the slightly more vulnerable VSAN outdoors. If some farmer with his tractor rips your single mode fiber, only the outdoor VSAN will be fractured and the indoor VSANs remain unharmed. And of course communication between the remote sites is interrupted, but the indoor VSANs / fabrics remain unchanged.

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Setting Daylight Savings Time on a Cisco MDS switch

Cisco MDS

I recently ran into a log time difference at a customer’s site so I want to repeat my blog from last year (Configuring the timezone and NTP). It’s slightly different on Cisco LAN / Routing equipment, but on Cisco MDS SAN switches the DST configuration is set by using the following commands:

config t
clock summer-time CEST 5 Sun Mar 02:00 5 Sun Oct 03:00 60
copy run start

  • CEST means Central Europe Summer Time (you can use your timezone name instead if you like)
  • the first 5, followed by “Sun” means that the DST will become active on the LAST (5th, sometimes the 4th) Sunday of the month following the day you just named (March)
  • 02:00 is the time of day when the DST will become active (time will go forward)
  • the second 5, followed by “Sun” means that the DST will become active on the LAST (5th, sometimes the 4th) Sunday of the month following the day you just named (October)
  • 03:00 is the time of day when the DST will end (time will go back to normal, backwards, so from 03:00 in my example the clock will go back to 02:00)

You can check the date, time and timezone by typing “show clock”.

Cisco MDS NX-OS zoning on the CLI

Cisco MDS

The Cisco Fabric Manager or the newer DCNM can be great for creating a limited number of zones and aliases, but when the number of zones exceeds 10 or 20 or so, creating, cloning and editing these can be a pain in the B@TT.

FC-SWITCH-01# conf t
Enter configuration commands, one per line. End with CNTL/Z.


Create aliases:

FC-SWITCH-01(config)# fcalias name VM101-HBA1 vsan 45
FC-SWITCH-01(config)# member pwwn 20:21:22:25:B6:00:00:01

Enhanced zone session has been created. Please ‘commit’ the changes when done.


FC-SWITCH-01(config-fcalias)# fcalias name VM101-HBA1 vsan 45
FC-SWITCH-01(config-fcalias)# member pwwn 20:21:22:25:B6:00:00:02
FC-SWITCH-01(config-fcalias)# fcalias name VM102-HBA1 vsan 45
FC-SWITCH-01(config-fcalias)# member pwwn 20:21:22:25:B6:00:00:03

FC-SWITCH-01(config-fcalias)# device-alias commit

Create two new zones:

FC-SWITCH-01(config-zone)# zone name VM101-HBA1_VNX-5600-08-SPA6 vsan 45
FC-SWITCH-01(config-zone)# member fcalias VNX5600-08-SPA6
FC-SWITCH-01(config-zone)# member fcalias VM101-HBA1
FC-SWITCH-01(config-zone)# zone name VM102-HBA1_VNX-5600-08-SPB7 vsan 45
FC-SWITCH-01(config-zone)# member fcalias VNX5600-08-SPB7
FC-SWITCH-01(config-zone)# member fcalias VM102-HBA1
FC-SWITCH-01(config-zone)# zone commit vsan 45

Commit operation initiated. Check zone status

Now add the two new zones to a zoneset:

FC-SWITCH-01(config)# zoneset name ZS_VSAN170 vsan 45
FC-SWITCH-01(config-zoneset)# member VM101-HBA1_VNX-5600-08-SPA6
FC-SWITCH-01(config-zoneset)# member VM102-HBA1_VNX-5600-08-SPB7
FC-SWITCH-01(config-zoneset)# zone commit vsan 45


Maximum distances using fiber cable types OM1/OM2/OM3/OM4/OS1

What are the maximum distances using different fiber grades?


fiber cable specs graph

The graphs show the direction where OM-specs are going compared to distances.

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Cisco MDS: Fabric is already locked

Cisco MDS

When you encounter a fabric lock, because you accidentally left the GUI or CLI without committing the changes, you can try the following to clear the lock and retry to apply your changes:

  1. run ‘show cfs lock’ to see who lock`s the fabric
  2. run ‘clear device-alias session’ to clear the lock when you were doing zoning activities

Instead of the “clear device-alias session” in line 2, another common possibility to get the lock cleared is:

  • ‘clear ivr session’ (when you were in the middle of IVR activities)

Other locks can occur, but the device-alias and ivr are probably the most common. At least the ones that I encountered so far.

Cisco zoning: some commonly used – show – commands

Cisco MDS

When you need to look up the current zoning config of a Cisco SAN-switch / VSAN, there’s a number of commands that will help you. Because a “show run” doesn’t always do the trick well, especially if you have a large config. And using the “sh run | i “some text you’re looking for” doesn’t always help as well if you don’t know the exact phrase you’re looking for.

I hope this table helps:

show Command
show zone Displays zone information for all VSANs.
show zone vsan 100 Displays zone information for VSAN 100.
show zoneset vsan 100 Displays information for the zone set in VSAN 100.
show zoneset vsan 2-5 Displays configured zone set information for a range of VSANs (2, 3, 4 and 5 in this case).
show zone name AZone Displays members of zone “AZONE”.
show fcalias vsan 100 Displays fcalias configuration in VSAN 100.
show zone member pwwn 20:00:00:25:b1:34:aa:c2 Displays membership status of a port wwn. Very good if you’re concerned that 1 HBA is used in more than 1 zone!
show zone statistics Displays zone statistics.
show zone statistics read-only-zoning Displays read-only zoning statistics.
show zoneset active Displays the active zone sets.
show zoneset brief Displays brief descriptions of zone sets.
show zone active Displays the active zones.
show zone status Displays zone status.
show zone Displays zone statistics.
show running Displays the interface-based zones.

Cisco Smart Zoning: is it really worth the effort? YES!

It’s been available since NX-OS 5.2(6), but is the community ready for a change? It seems the majority of SAN managers are still afraid to start using it, but why? the concept is so simple: it looks like the infamous “default zone” has made it’s way back to the storage area network, but with a twist.

Default zoning

When I was introduced to the world of Fibre Channel, over ten years ago, I remember going through the automatic steps of setting up a freshly powered-on SAN-switch and disabling the default zone, because that one makes that all initiators and targets can communicate with each other. And two initiators talking to each other is not done, because on the midrange arrays an initiator (used for data replication) can also be a target and you don’t want ports logging into each other.

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Cisco releases update for its SAN switches to fix the Shellshock aka Bashbug

Cisco MDS

Although I was triggered by a daily update I received from EMC in this knowledge base article: https://support.emc.com/kb/194669, it was Cisco who finally published an update for various firmwares that did not have a fix yet for the shellshock aka bashbug.
You can find all Release Notes on the Cisco site at http://www.cisco.com/c/en/us/support/storage-networking/mds-9000-nx-os-san-os-software/products-release-notes-list.html.
The EMC version of the Release Notes can be found here:

If you haven’t upgraded yet, I’d plan to do so in the very near future!

Which Cisco NX-OS should I use?

This time a really short reminder-like post. Somehow I often end up trying to locate certain release notes of various equipment, but Cisco organized theirs for the SAN switches in an orderly manner: Release Notes

Every NX-OS version is listed here and in each all supported equipment is named. I found this to be very helpful.

Cisco anounces their Data center Champions for 2014

Cisco Champions badge

Cisco Data center Champions 2014

Just like other big IT names like VMware with their vExpert, Microsoft with their MVP and since last year EMC with their Elect, now Cisco started their own community appreciation program called Cisco Champions. I want to focus on Data center Champions in particular since that’s the business I’m in myself. I’m not (much) into Cisco Data center networking technologies myself (yet), other than SAN related Fibre Channel equipment, but I’d like to dedicate this post to the start of this new community appreciation program nevertheless. The “community” is all that matters these days, right? Sharing knowledge to enhance the community “brain” as a whole. Being part of the 10 original founders of the EMC Elect I know how important proper communication can be for new programs like this and since Amy Lewis was kind enough to invite Allen Ward, Sergey Kamenetskiy and myself to shine in one of the “Engineers Unplugged” series in May 2013 in Las Vegas during EMC World, I thought, let’s return the favor and promote the Cisco Champions a bit, hoping for more collaboration and improvement of the awareness that even though social networking is some way of “virtual presence to people you might not even know”,  if your network is large enough it can also be seen as your online think-tank.

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Social acknowledgement: Cisco Champion for Datacenter

Cisco does Social Media recognition

It didn’t come as a surprise: after Microsoft MVP, VMware vExpert and the relative new EMC Elect program, Cisco just started another social champions program called “Cisco Champion for Datacenter”.

Who is that typical Cisco Champion? You’ve got to have passion and the desire to share your perspectives with the community. Cisco Champions are spread all over the world. Champions represent various segments across the whole IT industry and they spend their own private time to help others.

In addition to sharing their insights and expertise, Cisco Champions make a difference by:

  • Supporting their peers in social communities, forums and networks
  • Sharing their relevant experiences and thoughts on Cisco blogs
  • Providing valuable feedback directly to Cisco
  • And even more (so they say, but exactly what is still unclear)

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Cisco becomes a storage vendor

Twitter, Facebook, Google+… it’s all over the (social) news

Wednesday September 11 it was all over the news: all my popular news resources mentioned in one way or the other that Cisco is now into storage. The “Software Defined Data Center” buzz word is “buzzing” since the beginning of 2013, at least I didn’t hear much of it before that.

Many companies (including my employer Open Line Consultancy with Storage As A Service and Backup As A Service) already do business this way for years, it’s just that all of a sudden it has a popular name that everybody’s using since this year. But thinking about clouds with automated processes to fine tune and schedule every wish for storage, cpu or memory has really become popular. And with Cisco now acquiring Whiptail, this vendor will now be able to participate in this rising market space.

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