OTV Multicast-Mode Configuration Example Using OTV On Stick Design - OTV Series Part 3

 

Configuration Template Used In Demo:

DC1-N7K-1
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
vlan 200
 name OTV-EXTEND-VLAN
!
int lo0
 ip add 11.11.11.11/32
 exit
!
int e1/7
 ip add 1.1.1.1 255.255.255.0
 no sh
 exit
!
int e1/5
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
feature interface
!
feature pim
!
int vlan 200
 ip add 200.0.0.1/24
 no sh
 exit
!
int e1/1,e1/7
 ip igmp ver 2
 ip pim sp
 exit
!
ip pim rp-add 30.0.0.1
!


DC2-N7K-1
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
vlan 200
 name OTV-EXTEND-VLAN
!
int lo0
 ip add 22.22.22.21/32
 exit
!
int e1/14
 ip add 2.2.2.1 255.255.255.0
 no sh
 exit
!
int e1/12
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
feature interface
!
feature pim
!
int vlan 200
 ip add 200.0.0.2/24
 no sh
 exit
!
int e1/10,e1/14
 ip igmp ver 2
 ip pim sp
 exit
!
ip pim rp-add 30.0.0.1
!



DC1-N7K-2
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
vlan 200
 name OTV-EXTEND-VLAN
!
int lo0
 ip add 111.111.111.111/32
 exit
!
feature otv
!
int e1/11
 ip add 1.1.1.2 255.255.255.0
 ip igmp ver 3
 no sh
 exit
!
int e1/9
 sw
 sw mode tr
 sw tr all vlan 100,200
 no sh
 exit
!
otv site-vlan 100
 exit
!
otv site-iden 0x001
!
int overlay 1
 otv join-interface e1/11
 otv control-group 235.0.0.1
 otv data-group 232.0.0.0/4
 otv extend-vlan 200
 no sh
exit
!


DC2-N7K-1
+++++++++
!
vlan 100
 name OTV-SITE-VLAN
vlan 200
 name OTV-EXTEND-VLAN
!
int lo0
 ip add 222.222.222.222/32
 exit
!
feature otv
!
int e1/20
 ip add 2.2.2.2 255.255.255.0
 no sh
 ip igmp ver 3
 no sh
 exit
!
int e1/18
 sw
 sw mode tr
 sw tr all vlan 100,200
 no sh
 exit
!
otv site-vlan 100
 exit
!
otv site-iden 0x002
!
int overlay 1
 otv join-interface e1/20
 otv control-group 235.0.0.1
 otv data-group 232.0.0.0/4
 otv extend-vlan 200
 no sh
exit
!

Further Readings:

http://routing-bits.com/2011/06/16/cisco-otv-part-i/

http://routing-bits.com/2011/06/28/cisco-otv-part-ii/

http://routing-bits.com/2011/07/06/cisco-otv-part-iii/

http://blog.ine.com/2010/02/15/what-is-overlay-transport-virtualization/

http://blog.ine.com/2012/08/17/otv-decoded-a-fancy-gre-tunnel/

http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/5.0/OTVmulticast.pdf

http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/whitepaper/DCI3_OTV_Intro_WP.pdf

http://www.netcraftsmen.net/user-group/c-mug-archive/904-overlay-transport-virtualization.html

http://www.netcraftsmen.net/blogs/entry/spanning-layer-2-between-data-centers.html

http://www.netcraftsmen.net/blogs/entry/understanding-layer-2-over-layer-3-part-1.html

http://www.netcraftsmen.net/blogs/entry/understanding-layer-2-over-layer-3-part-2.html

http://www.netcraftsmen.net/blogs/entry/exploiting-layer-2-over-layer-3.html

http://www.netcraftsmen.net/blogs/entry/otv-optimal-routing.html

http://www.netcraftsmen.net/blogs/entry/cisco-overlay-transport-virtualization-otv.html

http://www.netcraftsmen.net/blogs/entry/data-center-l2-interconnect-and-failover.html

http://www.netcraftsmen.net/blogs/entry/designing-an-otv-deployment.html

http://www.netcraftsmen.net/blogs/entry/otv-and-dci-require-stp-defenses.html

http://packetpushers.net/pq-show-24-cisco-otv-deep-dive-part-1/

http://packetpushers.net/pq-show-25-cisco-otv-deep-dive-part-2/

http://packetpushers.net/show-155-integrating-otv-fabricpath-lisp-sponsored/

http://packetpushers.net/cisco-otv-101-legacy-multicast-mode-mac-learning-process-walk/

http://packetpushers.net/anycast-hsrp-design-considerations/

HTH...
Deepak Arora
Evil CCIE

OTV Unicast-Mode Configuration Example Using OTV On Stick Design - OTV Series Part 2

Note: DC1-N7K-2 Is Playing Role Of OTV Unicast Adj. Server

Configuration Template Used In Demo:

Getting Infrastructure Ready
############################

DC1-N7K-1
+++++++++

!
en
!
conf t
!
feature interface-vlan
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
int vlan 200
 ip add 200.0.0.1/24
 no sh
 exit
!
int e1/5
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
int e1/7
 ip add 1.1.1.1/24
 < Enable Routing Of Your Choice >
 no sh
 exit
!
int e1/1
 ip add 10.1.13.3/24
 < Enable Routing Of Your Choice >
 no sh
 exit
!

DC2-N7K-1
+++++++++

!
en
!
conf t
!
feature interface-vlan
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
int vlan 200
 ip add 200.0.0.2/24
 no sh
 exit
!
int e1/12
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
int e1/14
 ip add 2.2.2.1/24
 < Enable Routing Of Your Choice >
 no sh
 exit
!
int e1/10
 ip add 10.1.23.3/24
 < Enable Routing Of Your Choice >
 no sh
 exit
!


DC1-N7K-2
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
int e1/9
 des "OTV-INTERNAL-INTERFACE"
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
int e1/11
 des "OTV-JOIN-INTERFACE"
 ip add 1.1.1.2/24
 < Enable Routing Of Your Choice >
 no sh
 exit
!


DC2-N7K-2
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
int e1/18
 des "OTV-INTERNAL-INTERFACE"
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
int e1/11
 des "OTV-JOIN-INTERFACE"
 ip add 2.2.2.2/24
 < Enable Routing Of Your Choice >
 no sh
 exit
!

****************************************

OTV Configurations
##################


DC1-N7K-2
+++++++++

!
en
!
conf t
!
feature otv
!
otv site-vlan 100
 exit
!
otv site-identifier 0x01
!
int overlay 1
 otv join-interface e1/11
 otv adjacency-server unicast-only
 otv extend-vlan 200
 no sh
 exit
!


DC2-N7K-2
+++++++++

!
en
!
conf t
!
feature otv
!
otv site-vlan 100
 exit
!
otv site-identifier 0x02
!
int overlay 1
 otv join-interface e1/20
 otv use-adjacency-server 1.1.1.2 unicast-only
 otv extend-vlan 200
 no sh
 exit
!

Further Readings:

http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/whitepaper/DCI3_OTV_Intro_WP.pdf

HTH...
Deepak Arora
Evil CCIE

OTV Unicast-Mode Configuration Example Using OTV In Path Design - OTV Series Part 1

Note:- 100.100.100.100 is Redundant Unicast Adjacency Server In This Configuration Example & DC1-N7K-1 Is Primary Unicast Adj. Server In This Configuration Example.

Configuration Template Used In Demo:

DC1-N7K-2
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
int e1/9
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
feature interface-vlan
!
int vlan 200
 ip add 200.0.0.1/24
 no sh
 exit
!
end
!


DC2-N7K-2
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
int e1/18
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
feature interface-vlan
!
int vlan 200
 ip add 200.0.0.2/24
 no sh
 exit
!
end
!


DC1-N7K-1
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
system jumbo 9216
!
feature otv
!
int e1/5
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
otv site-identifier 0x01
!
otv site-vlan 100
 exit
!
interface overlay 1
 otv join-interface e1/1
 otv adjacency-server unicast-only
 otv use-adjacency-server 10.1.13.3 100.100.100.100 unicast-only
 otv extend-vlan 200
 no sh
 exit
!


DC2-N7K-1
+++++++++

!
en
!
conf t
!
vlan 100
 name OTV-SITE-VLAN
 exit
!
vlan 200
 name OTV-EXTEND-VLAN
 exit
!
system jumbo 9216
!
feature otv
!
int e1/12
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 no sh
 exit
!
otv site-identifier 0x02
!
otv site-vlan 100
 exit
!
interface overlay 1
 otv join-interface e1/10
 otv use-adjacency-server 10.1.13.3 100.100.100.100 unicast-only
 otv extend-vlan 200
 no sh
 exit
!

Further Readings:

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/wan_otv/configuration/xe-3s/wan-otv-xe-3s-book/wan-otv-adj-server.html

http://www.cisco.com/c/en/us/products/collateral/switches/nexus-7000-series-switches/white_paper_c11-644634.html

http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/5.0/OTVunicast.pdf

https://supportforums.cisco.com/document/64881/troubleshooting-arp-issues-across-otv

https://supportforums.cisco.com/document/65531/otv-silent-host-connectivity-problem

HTH...
Deepak Arora
Evil CCIE

Nexus 5K FEX, vPC & EvPC - All In One

Note: During the Video Demo the topology shown was little incorrect. Refer topology posted above during video demo.

N5K-1
+++++

!
en
!
conf t
!
vlan 100,200
 exit
!
feature vpc
!
feature lacp
!
feature fex
!
vpc domain 100
 role priority 1
 peer-keepalive dest 10.1.1.52 sou 10.1.1.51 vrf management
 exit
!
int e1/14-15
 channel-group 200 mode active
 no sh
 exit
!
interface port-channel 200
 switchport mode trunk
 vpc peer-link
 no sh
 exit
!
int e1/17
 channel-group 100
 no sh
 exit
!
int port-channel 100
 switchport mode fex
 fex associate 100
 vpc 100
 no sh
 exit
!
int e1/16
 channel-group 199
 no sh
 exit
!
int port-channel 199
 switchport mode fex
 fex associate 199
 vpc 199
 no sh
 exit
!
int e100/1/1,e109/1/1
 no sh
 channel-group 300
 exit
!
int port-channel 300
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 spanning-tree port type edge trunk
 no sh
 exit
!
end
!
===========================================================

N5K-2
+++++

!
en
!
conf t
!
vlan 100,200
 exit
!
feature vpc
!
feature lacp
!
feature fex
!
vpc domain 100
 role priority 1
 peer-keepalive dest 10.1.1.51 sou 10.1.1.52 vrf management
 exit
!
int e1/14-15
 channel-group 200 mode active
 no sh
 exit
!
interface port-channel 200
 switchport mode trunk
 vpc peer-link
 no sh
 exit
!
int e1/16
 channel-group 100
 no sh
 exit
!
int port-channel 100
 switchport mode fex
 fex associate 100
 vpc 100
 no sh
 exit
!
int e1/17
 channel-group 199
 no sh
 exit
!
int port-channel 199
 switchport mode fex
 fex associate 199
 vpc 199
 no sh
 exit
!
int e100/1/1,e109/1/1
 no sh
 channel-group 300
 exit
!
int port-channel 300
 switchport mode trunk
 switchport trunk allowed vlan 100,200
 spanning-tree port type edge trunk
 no sh
 exit
!
end
!

Further Readings:
==============

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/interfaces/7x/b_5500_Interfaces_Config_Guide_Release_7x/b_5500_Interfaces_Config_Guide_Release_7x_chapter_0101.html

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/layer2/7x/b_5500_Layer2_Config_7x/b_5500_Layer2_Config_7x_chapter_01111.html

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/mkt_ops_guides/513_n1_1/n5k_enhanced_vpc.html

http://www.cisco.com/c/en/us/support/docs/switches/nexus-5000-series-switches/116271-problem-vpc-00.html

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/troubleshooting/guide/n5500_trouble/n5500_ts_vpc.html

HTH...
Deepak Arora
Evil CCIE

Finally Much Awaited Nexus 9000 Is Available - Next Step Towards High Density 10/40GE Adoption in Application Aware Data Center Space

www.cisco.com/go/nexus9000

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps13386/white-paper-c11-729987.html

HTH...

Deepak Arora

Evil CCIE

Cisco Catalyst 6500/6800 Instant Access - Answer To Cisco Nexus 2000 AKA FEX For Enterprise ?

As Cisco Launched its Next Gen Catalyst 6000 Series as Catalyst 6800 based on One of it's most successful Enterprise switch product Cat 6500's DNA at recent Cisco Live Event At Orlando, There was an advantage that competing Nexus Series had even as solution to Enterprise market was Nexus 2000 AKA FEX, which was offering lots of benefits.

While the roadmap/investment protection of Nexus Family is yet to be clarified by Cisco as they keep coming with newer versions and flavors, the Cat 6500 always seen as very mature platform for Enterprise solutions.

Even to compete further with Nexus family, Cisco Catalyst team came up with a latest solution recently as INSTANT ACCESS (IA).

The benefits Cisco IA offers are some what similar to Nexus 2000/FEX. Though there are few hard requirements like :

> SUP 2T

> VSS CODE

> Switches To be configured in VSS Mode even if it's a standalone chassis

> 6904 10/40Gig line cards to be operated in 10Gig mode only

Further Readings:

http://www.cisco.com/en/US/prod/collateral/switches/ps10902/ps715/ps13198/white_paper_c11-728265.html

http://www.cisco.com/en/US/prod/collateral/switches/ps10902/ps715/ps13198/qa_c67-728684_ns1240_Networking_Solutions_Q_and_A.html

http://www.cisco.com/en/US/netsol/ns1240/index.html#~Overview

HTH...
Deepak Arora
Evil CCIE

Catalyst 6800 - A new Cisco Baby to replace Cat 6500

As the Cisco Live 2013 at Orlando is keep going on, Cisco just announced a New Baby into Catalyst family as Cat 6800. Based on Cat 6500 DNA with better performance (Perhaps matching Nexus) and backward compatibility with Cat 6500 series line cards the new Baby is meant to replace current Cat 6500 and give an option to people which probably don't want to move on to Nexus yet.

More Information
++++++++++++


http://www.youtube.com/watch?v=NHYWAE8FIzk 

http://www.youtube.com/watch?v=K-igQ-UsUz8

www.cisco.com/go/6800


HTH...
Deepak Arora
Evil CCIE

http://www.youtube.com/watch?v=K-igQ-UsUz8

Initializing Nexus 5K For Storage - (Storage Series Part-2)

As I continue my journey with storage networking, I compiled some more notes today covering Nexus 5K initialization from Fiber Channel Implementation Perspective. Hope you guys will enjoy !!!

 ######################################################################

 * To verify SAN Port type and topology on N5k => sh int brief

+ In output look under " Oper Mode "

Sample SAN Port Channel Config
==============================

interface san-port-channel 1
 channel mode active
 switchport mode E
 swithcport trunk allowed vsan 1
 switchport trunk allowed vsan add 10
 switchport speed 4000


* Changing Port Type to FC in 5k
================================

slot 1 or 2
 port 25 - 32 type fc

+ Requires Reload

# " feature fcoe " needs to be turned on separately in order to enable basic FC protocol
     which also further enables actual FCOE. Though NPV for FCOE requires separate license.

+ If port type has been changed to FC but feature fcoe is not enabled, the FC ports 
    will not show up in "sh int brief" output. Also we will not be able to go into FC interface 
    configuration mode.

+ The SFP for storage connecivity is different from SFP for Ethernet connection from 5K standpoint

* FC Auto Negotiation
=====================

> FC Auto Negotiation is enabled by default

> Auto Negotiation Determines:

+ Port Type [ switchport mode ]

+ Trunk Mode [ switchport trunk mode ]

+ Speed [ switchport speed <1000> ]

- From real world standpoint, Port Types etc should be configured manually

* MDS Auto-Negotiation
======================

- MDS port types are by default FX which means it can figure out if it needs to be F or FL 
    port mode during auto-negotiation

- MDS usually can't negotiate E ports so ISL must always be configured manually.

- In MDS E port requires dedicated rate-mode [switchport rate-mode dedicated ]

+ In FC network it's not only SFP type that will control the link speed but also Optical 
    cable should be of same speed in order to match it

+ In FC network there is something known as B2B or Buffer To Buffer credit which is
   analogous to Flow Control is Ethernet Networks.B2B works per link basis and on end 
   to end basis between initiator & target


* FC Trunk Protocol
===================

- Trunk protocol (TP) in FC is analogous to DTP in ethernet and is enabled by default

- Verification - sh trunk protocol

- To disable TP - switchport trunk mode on (Default - auto)

But keep in mind there is no command called "switchport mode te" to statically configure TE port

Nexus Configuration Roll Back - Using Checkpoint Feature

While I have just started preparing for my CCIE DC. I must say I am in love with this track. Although majority of the track is focused on Cisco Specific Products - NEXUS Series, ACE, UCS etc, still there is lot of technology to learn working behind the scenes. 

So I have started my studies with Nexus. While there are couple of similarities between NX-OS and our old  buddy regular IOS. There are many major differences as well.

So today we are going to talk about a relatively small but important Nexus OS feature which should be very helpful to you in production setup. 

The feature is called CHECKPOINT. Essentially the feature is somewhat similar to our regular IOS feaure known as "Configure Replace". But NX-OS has taken the feature a step further in order to allow us more flexiability.

Basically CHECKPOINT feature allows us to save a snapshot of configuration at any given time (Though Per VDC we can have at max 10 checkpoints). At any given time if we feel there are too many mistakes we have made. Using Checkpoint we can revert to last snapshot of configuration very quickly. This is certainly a nice feature from Cisco or are we just following Microsoft now ;-)

So let's hop on to Nexus CLI and perform some basic testing in order to completely understand the feature:

N7K11-pod3# sh ver | i kick|system|Nexus
Cisco Nexus Operating System (NX-OS) Software
  kickstart: version 5.2(4)
  system:    version 5.2(4)
  kickstart image file is: bootflash:///n7000-s1-kickstart.5.2.4.bin
  kickstart compile time:  12/25/2020 12:00:00 [03/08/2012 03:58:13]
  system image file is:    bootflash:///n7000-s1-dk9.5.2.4.bin
  system compile time:     1/28/2012 23:00:00 [03/08/2012 04:59:07]
  cisco Nexus7000 C7010 (10 Slot) Chassis ("Supervisor module-1X")

Step 1. Create a Checkpoint

N7K11-pod3# checkpoint

user-checkpoint-1 created Successfully

Done


N7K11-pod3# sh checkpoint
--------------------------------------------------------------------------------
Name: user-checkpoint-1



N7K11-pod3# sh checkpoint summary
User Checkpoint Summary
--------------------------------------------------------------------------------
1) user-checkpoint-1:
Created by admin
Created at Tue, 11:04:46 02 Oct 2012
Size is 5,102 bytes
Description: None


Step 2. Check the difference between Checkpoint Snapshot Config & Running Config

N7K11-pod3# sh diff rollback-patch checkpoint user-checkpoint-1 running-config
Collecting Running-Config
#Generating Rollback Patch
Rollback Patch is Empty

As you guys can see , currently rollback patch is empty. Which mean Checkpoint config is same as current running-configuration. Let's make some changes now in current running configuration in order to make difference between two.

N7K11-pod3(config)# username deepak password 0 cisco role priv-15
N7K11-pod3(config)# end


N7K11-pod3# sh diff rollback-patch checkpoint user-checkpoint-1 running-config
Collecting Running-Config
#Generating Rollback Patch

!!
!
username deepak password 5 $1$dVPagLUf$RFkUQOcY2F4gb8YisS8vn1 role priv-15
snmp-server user deepak priv-15 auth md5 0x3d98e4cead6825e6669d98dc60209308 priv 0x3d98e4
cead6825e6669d98dc60209308 localizedkey

To Delete old checkpoint configuration snapshot, we can run following command:

N7K11-pod3# clear checkpoint database
...............Done


N7K11-pod3# sh checkpoint summary
N7K11-pod3#

Let's create a fresh checkpoint again:

N7K11-pod3# checkpoint

user-checkpoint-2 created Successfully

Done



N7K11-pod3# sh checkpoint summary
User Checkpoint Summary
--------------------------------------------------------------------------------
1) user-checkpoint-2:
Created by admin
Created at Tue, 11:11:12 02 Oct 2012
Size is 5,307 bytes
Description: None


N7K11-pod3# sh user-account
user:admin
        this user account has no expiry date
        roles:vdc-admin
user:deepak
        this user account has no expiry date
        roles:priv-15
Let's delete the user and try to get back using Checkpoint Snapshot:

N7K11-pod3# conf t
Enter configuration commands, one per line.  End with CNTL/Z.
N7K11-pod3(config)# no username deepak password 0 cisco role priv-15
N7K11-pod3(config)# end


N7K11-pod3# sh user-account
user:admin
        this user account has no expiry date
        roles:vdc-admin


N7K11-pod3# rollback running-config checkpoint user-checkpoint-2
Note: Applying config parallelly may fail Rollback verification
Collecting Running-Config
#Generating Rollback Patch
Executing Rollback Patch
Generating Running-config for verification
Generating Patch for verification
Rollback Patch is Empty

Rollback completed successfully.


N7K11-pod3# sh user-account
user:admin
        this user account has no expiry date
        roles:vdc-admin
user:deepak
        this user account has no expiry date
        roles:priv-15



N7K11-pod3# sh rollback log verify
Operation            : Rollback to Checkpoint
Checkpoint name      : user-checkpoint-2
Rollback done By     : admin
Rollback mode        : atomic
Verbose              : disabled
Start Time           : Tue, 11:16:48 02 Oct 2012

Further Readings:

http://www.cisco.com/en/US/docs/switches/datacenter/sw/5_x/nx-os/system_management/configuration/guide/sm_7rollback.html

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/system_management/502_n1_1/Cisco_n5k_system_mgmt_cg_rel_502_n1_1_chapter11.html


HTH...
Deepak Arora
Evil CCIE