With Prashanth Krishnappa
Welcome to the Cisco Support Community Ask the Expert conversation. This is an opportunity to learn about how to troubleshoot the Nexus 5000/2000 series switches.
Prashanth Krishnappa is an escalation engineer for datacenter switching at the Cisco Technical Assistance Center in Research Triangle Park, North Carolina. His current responsibilities include escalations in which he troubleshoots complex issues related to the Cisco Catalyst, Nexus and MDS product lines as well as providing training and author documentation. He joined Cisco in 2000 as an engineer in the Technical Assistance Center. He holds a bachelor's degree in electronics and communication engineering from Bangalore University, India, and a master's degree in electrical engineering from Wichita State University, Kansas. He also holds CCIE certification (#18057).
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Most of the features including L3 features are enabled using the feature command. Here is an output from a lab switch
5548-1(config)# feature ?
bgp Enable/Disable Border Gateway Protocol (BGP)
cts Enable/Disable CTS
dhcp Enable/Disable DHCP Snooping
dot1x Enable/Disable dot1x
eigrp Enable/Disable Enhanced Interior Gateway Routing Protocol (EIGRP)
fcoe Enable/Disable FCoE/FC feature
fcoe-npv Enable/Disable FCoE NPV feature
fex Enable/Disable FEX
flexlink Enable/Disable Flexlink
hsrp Enable/Disable Hot Standby Router Protocol (HSRP)
http-server Enable/Disable http-server
interface-vlan Enable/Disable interface vlan
lacp Enable/Disable LACP
msdp Enable/Disable Multicast Source Discovery Protocol (MSDP)
npiv Nx port Id Virtualization (NPIV) feature enable
npv Enable/Disable FC N_port Virtualizer
ospf Enable/Disable Open Shortest Path First Protocol (OSPF)
pim Enable/Disable Protocol Independent Multicast (PIM)
port-security Enable/Disable port-security
private-vlan Enable/Disable private-vlan
privilege Enable/Disable IOS type privilege level support
rip Enable/Disable Routing Information Protocol (RIP)
ssh Enable/Disable ssh
tacacs+ Enable/Disable tacacs+
telnet Enable/Disable telnet
udld Enable/Disable UDLD
vpc Enable/Disable VPC (Virtual Port Channel)
vrrp Enable/Disable Virtual Router Redundancy Protocol (VRRP)
vtp Enable/Disable Vlan Trunking Protocol (VTP)
So if a feature is not needed, you can turn it off using "no feature".
Thank you for your reply. Does that mean that if I do not turn on any L3 features on the Nexus 5500, I can be able to scale up to 24 FEXs dual-homed?
P.s. yup, I have L3 daughterboard installed
The switch is considered Layer 3 only when you install the L3 licenses. So if you do not need the L3 features at this time and want to use it as L2 switch with upto 24 FEX, you could uninstall all the L3 licenses.
Correct me if I'm wrong, What I do to be able to scale up to 24 FEXs is by backing up my licenses, then uninstalling the L3 license. And if one day in the future I need this L3 feature, I just restore my license from the backup that I've made?
Btw, how do I restore backed up licenses on the N5500? I can't seem to find any guides on it.
Thanks in advance.
Just installing license using "clear license" command should be enough. Here is an example from my lab switch.
5548-1# clear license ?
WORD License file to be uninstalled
But if you want to back up all the license files, you can do that too. Here is how you do it.
1)copy license bootflash:file-name.tar
2)Then issue "clear license" like above.
If you need to, reinstall the license at some point in the future
1)tar extract bootflash:file-name.tar
2)Install the license back using "install license bootflash:" command.
Question about Enhanced vPC-
"The Dual-homed FEX topology can also be deployed for servers that have multiple NICs
but do not support 802.3ad"
Does the above statement mean we can't use LACP to dual home a server to dual homed FEXs?
here is one simple question: if I have Nexus 5k connected to another cisco device that also supports vPC, will CDP work if port on one side belongs to vPC while on another side is configured as simple access port?
I'm curently facing a similar problem. Do you het an answer or solve this issue?
The Cisco answer is diabling Layer 3 features but do we need to rmove the license and / or the Layer 3 card?
Newer versions of NX-OS supports up to 16 EvPCs (my customer uses 10 FEXs so far) hence I did not attempt to try out removing the licenses. I have yet to try removing the license as my project timeline grew shorter and I was unable to test anymore. If you have the time, do give Prashant's guides a try and let us know If I have a chance to deal with N55XX with L3 module, I will attempt to try this out
Is this post still active?
Would like to ask further on L3 modules. Lets say I'm performing an NX-OS upgrade on a Nexus5500 series which is equipped with L3 module. I have L3 license installed, however I do not use any L3 capabilities at all.
Whenever I perform an ISSU check for upgrading, the output will always be "disruptive" which I suspect is due to the reason that I have an L3 module installed. I know for a fact that my configurations on a Nexus5500 unit without an L3 module will be non-disruptive. Can I safely tell the customer that their production network will not encounter any downtime if I perform an NX-OS upgrade?
Thanks in advance!