Hi Bhavesh, Cisco FabricPath is currently only available on Nexus series , i heard about plans of introducing it on other Cisco platforms but cannot comment on when that will happen. Regards, Iqbal ... View more

Hi, VPC+ is very similar to VPC in terms of how it operates , so your hosts can connect to two switches which are VPC+ peers.You can have two VPC+ peers in a domain. Regards, Iqbal ... View more

Hi Shiva Nandan, You posted the question in the worng forum , please contact Cisco Sertification support at the url below to get an answer to your question : http://ciscocert.force.com/english Regards, Iqbal ... View more

Hi Tenaro, Thanks for your question ...As Hatim mentioned in the reply above - there are lot of reasons to migrate to Cisco Fabricpath from either a STP based or a VPC based architecture..I am summarizing some of them below : - Scalability :Cisco Fabricpath allows you to scale to much larger extent compared to a STP or VPC based design mainly because FP is not using STP at all ( unlike VPC which is still using VPC in the background ) , so because you are not using STP you dont have to worry about blocking vs forwarding ports as well as things like STP logical ports which is huge consideration for scale when designing any networks using STP. - Growth : Even if you have two spines ( like in VPC designs ) - its still a good idea to consider FP solution because FP will allow you to easily grow in future without making significant changes in the design - L2 Domain segmentation : Despite all the benefits VPC offers, you still cant avoid L2 domain segmentation where your vlans are typically segmented to a particular POD unlike in FP all of your vlans are available everywhere in the FP network. - Flexibility : With VPC you are still looking at a single design which is supported by VPC , unlike with FP you can design the network the way you want to with complete flexibility . - Bandwidth : the bandwidth increase with VPC compared to a STP design is typically double however with FP you get huge improvement over bandwidth availability as detailed by Hatim above. - MAC address scale : the typical STP networks we are used ( same with VPC ) has drawbacks when it comes to scaling of mac addresses essentially because we are used to concept that every device will learn every mac address in a transit network.FP offers conversational learning which is a new and innovative way of handling mac address learning .With Convesational learning - the devices which are either connected to source or destination hosts will learn the mac address , all the other devices in transit will not learn that mac address thereby providing major scalability benefits to mac address scale. Hope that helps. Finally to answer your questions about Cisco properietary - yes FP is Cisco properietary feature but having said that we are also going to support TRILL which is standard based feature very similar to FP ( mostly based upon FP ) .However FP offers a lot more benefits over TRILL with features such as convesational learning , VPC+ etc which are not available with TRILL. Regarding VPC+ ....VPC+ is FP variant of VPC ...so its pretty much similar to VPC but has a different name VPC+ when its used in FP environment.This is a way for hosts connecting to FP network to connect in an active-active fashion. Hope that answers all of your questions . Let us know if you have any more questions. Regards, Iqbal ... View more

Hi Danny, As mentioned earlier - It is strongly recommended to dual attach every device to vPC domain to avoid the isolation of the orphan ports in case of peer link failure. I would suggest you to consider the following 3 design options before opting the option 4 which is the orphan port design you are currently considering. I have also listed down the pros and cons of each of the design options to help with your evaluation. If after evaluating the first three options, option 4 still seems the only feasible option for you, then I would encourage you to reconsider the vpc implementation at this point since by single homing the devices and using vpc , you are not really gaining anything anyway. It would be best for you to configure vpc when you are ready to go dual homed (dual connect ) with your devices. Hope that helps. Regards, Iqbal ******************** Here are the recommendations for connecting devices to vPC domain (in order of preference) •1.      ALWAYS try to dual attach devices using vPC (not applicable for routed links). PROS: Ensures minimal disruption in case of peer-link failover and consistent behavior with vPC dual-active scenarios. Ensures full redundant active/active paths through vPC. CONS: None •2.      If (1) is not an option – connect the device via a vPC attached access switch (could use VDC to create a “virtual access switch”). PROS: Ensures minimal disruption in case of peer-link failover and consistent behavior with vPC dual-active scenarios. Availability limited by the access switch failure. CONS: Need for an additional access switch or need to use one of the available VDCs. Additional administrative burden to configure/manage the physical/Virtual Device •3.      If (2) is not an option – connect device directly to (primary) vPC peer in a non-vPC VLAN  and provide for a separate interconnecting port-channel between the two vPC peers. PROS: Traffic diverted on a secondary path in case of peer-link failover CONS: Need to configure and manage additional ports (i.e. port-channel) between the Nexus 7000 devices. •4.      If (3) is not an option – connect device directly to (primary) vPC peer in a vPC VLAN PROS: Easy deployment CONS: Generally Bad. Bound to vPC roles, Full Isolation on peer-link failure when attached vPC toggles to a secondary vPC role. ... View more

Also to add our best practice recommendation would be to dual connect all devices to both the peers because in case of failure scenarios , the single homed devices would be isolated and traffic from them would be blackholed. ... View more

**Re-posting with minor edit** Hi There, To answer your question , by definition any vlan that is forwarded on the vpc peer link beocmes a vpc vlan ...If the devices are single homed ( i.e connected to only one peer either directly or via N2K) , then the question should be do you really want those vlans to be forwarded on the peer link and by doing so extend your L2 domain across the two peers ....because you can easily  configure the vlan only on the peer where the device is connected to and use an SVI for further connectivity.That way there will be no need to extend these vlans across on the peer link essentially making those vlans  'non-vpc' vlans. As for the Non-VPC vlan - any vlan which is not forwarded on the peer link is a non-vpc vlan and follows the regular STP rules , A lot of times customers use it for single homed devices or for the devices which arent capable of running etherchannel. Please also note that single attached devices that are not connected via a vPC ( including single homed )  but still carry vPC VLANs are also known as orphan ports.In case of a peer-link shut or restoration, an orphan port's connectivity may be bound to the vPC failure or restoration process Hope it is clear now. Regards, Iqbal ... View more

Hi Marwan, Agreed , Config-sync will help too! At this time - this feature is in the roadmap for N7K . Regards, Iqbal ... View more

Hi Giuseppe, Hmm ...I see  - yeah in your particular case - it makes sense as none of the in service vlans x,y,z are mgmt vlans . Anyway , thanks for bringing this scenario to our attention. Regards, Iqbal ... View more

Hi Giuseppe, Thanks for reporting your issue to us , we are constantly working to improve user experience with NX-OS . There is a new feature in NX-OS release 5.2 which can help in the scenarios like this , This feature is enabled by default ( cant be disabled) in 5.2 and is called 'Per-Vlan Consistency Check'.. ( Not applicable to Spanning tree MST Mode ) -------------------- http://www.cisco.com/en/US/partner/docs/switches/datacenter/sw/5_x/nx-os/interfaces/configuration/guide/if_vPC.html#wp1834065 -Currently if spanning-tree vlans enabled on vPC peers do not match, it is a global type-1 inconsistency and as such vPC peer-link and all vPCs on both peers are brought down - With Per-vlan consistency check, spanning-tree vlans that do not match on both peers, will be brought down on all vPCs and peer-link. Other vlans will stay up -------------------- Regards, Iqbal Syed ... View more

Hi Sean, VPC itself doesnt  impose any distance limitations between the two geographically seperated  DCs , the limitation would depend upon the optics in use and the kind  of interconnection (WAN Link ) you have between the two DCs. Please see the detailed document below for some of the testing performed in this area : http://www.cisco.com/en/US/solutions/collateral/ns340/ns517/ns224/ns949/ns304/ns975/data_center_interconnect_design_guide.pdf Similarly  there are no recommendations on SLA's in regards to latency , packet  loss etc , it will depend upon the applications in use and their  sensitivity to latency and packet loss.The bandwidth requirement would  be driven by the amount of traffc between the two DCs. As  such careful consideration should be given to these parameters and  thorough testing should be performed when designing a DCI soloution. HTH, Regards, Iqbal ... View more

Hi Mohamed, Please see your answers inline below: 1- Is a VPc is normal Layer-2 Etherchannel? and do we have VPc suuports for layer-3 forwarding just like we have layer-3 Etherchannel? There is a very good white paper explaining VPC , Its benefits and how L3 works over VPC below: http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9402/white_paper_c11-516396.html 2- If we have a pair of VPc devices connected a Core/distribution layer, and we have multiple nexus switches connected at the access layer, does the Access layer see both VPc Core Peers as One logical device? does this provides the same functionality as with Cisco VSS on the 6500 Switches? what is exactly the difference? Yes the access layer devices will see the VPC peers as one logical device .Regarding the differences between VPC and vss , just like Marwa mentioned , the major difference is the fact that VSS provides one control plane while VPC has two.For other differences , the document pointed by Reza would be a great reference. 3- Does enabling VPc provides ONLY rapid Convergence to a failure detection than Spanning-tree provides? and when enabling VPc on nexus, Do we actually eleminate the need of Spanning-tree protocol? The main difference between a vPC configuration and a non-vPC configuration is in the forwarding behavior of the vPC peer link and the BPDU forwarding behavior of vPC member ports only.Non-vPC ports on a vPC-configured switch behave in the same way as on a regular switch ( use STP), except that the vPC peer link is always forwarding, which may require a slightly different topology. Please refer to the document below which explains how STP works in a VPC environment along with examples: http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/C07-572834-00_STDG_NX-OS_vPC_DG.pdf 4- From the Access layer, if we have Nexus for example 5000 series, Can we have One VPc identifier connects to both Nexus 7000 Distrbuttion/COre VPc pair? I assume by VPC identifer you mean VPC domain , if yes then jst like Marwan mentioned wou will need two VPC domains 5- Does using VPc eleminate of using first Hop redundancy protocols like HSRP? and How frames are forwarded through the Active/Standby HSRP peers? do we have still One as Active and one as Standby , or this concept has changed with VPc? With VPC configured , HSRP is still needed however the improvement was made to the forwarding engine specifically to allow local Layer 3 forwarding at both the active HSRP peer and the standby HSRP peer. This enhancement provides, in effect, an active-active HSRP configuration with no changes to current HSRP configuration recommendations or best practices and no changes to HSRP. The HSRP control protocol still acts like an active-standby pair, so that only the active device responds to Address Resolution Protocol (ARP) requests, but a packet destined for the shared HSRP MAC address is accepted as local on either the active or standby HSRP device. Hope that Helps, Regards, Iqbal Syed ... View more