Nexus Features and Feature-Sets

Nexus Features and Feature-Sets

Last Updated: Sep 19, 2018 @ 1:21 am (UTC)

 

The Nexus platform is modular. Each feature has its own processes, independent of other features. To improve stability, these modules are only enabled as they’re needed. After all, a process that’s not running can’t cause a crash. This has an added benefit of decreasing the attack surface. Let’s not forget the resources savings when only loading required modules. How about upgrades? Yep, they get the benefit too. If a module has a fault, Cisco could release a patch that only updates that module. This helps limit the impact of an upgrade.

Features

To use Nexus features, they first have to be enabled. Sometimes, they have to be installed first. See a list of features with the show feature command.

Nexus Features
SY3NX01# show feature
Feature Name Instance State
-------------------- -------- --------
Flexlink 1 disabled
amt 1 disabled
bfd 1 disabled
bfd_app 1 disabled
bgp 1 disabled
bulkstat 1 disabled
cable-management 1 disabled
cts 1 disabled
dhcp 1 disabled
dot1x 1 disabled
eigrp 1 disabled
eigrp 2 disabled
eigrp 3 disabled
eigrp 4 disabled
eth_port_sec 1 disabled
evmed 1 disabled
fabric-access 1 disabled
fcoe 1 disabled
fcoe-npv 1 disabled
fex 1 enabled
glbp 1 disabled
hsrp_engine 1 enabled
http-server 1 disabled
interface-vlan 1 enabled
! ---Output omited for brevity---

To enable features. use the feature command. For example feature eigrp will enable the EIGRP processes. Some features, such as EIGRP may use more than one instance. Although this a single feature, each instance runs as a separate process.


Feature Sets

Besides features, there are also feature-sets. Feature sets are similar, except they represent a collection of processes. To use a feature, install it with the install feature-set command. Then, enable it with the feature-set command.

Nexus Feature Set
Switch(config)# install feature-set fabricpath
Switch(config)# feature-set fabricpath

Switch# show feature-set
Feature Set Name      ID        State
--------------------  --------  --------
fabricpath             2          enabled
fabric                 7          uninstalled
virtualization         5          uninstalled

Feature-sets are installed per VDC (on platforms that support VDC’s).

An example of a feature-set is fabricpath. This uses a collection of processes, which is why it is a feature-set. On the N7K, some processes run on the supervisor, and some run on the individual IO modules that use it.


Processes

To see a list of processes on the Nexus, use show process.

Nexus Processes
SY3NX01# show processes

PID    State  PC        Start_cnt    TTY   Process
-----  -----  --------  -----------  ----  -------------
    1      S  41520eb8            1     -  init
    2      S         0            1     -  kthreadd
    3      S         0            1     -  migration/0
    4      S         0            1     -  ksoftirqd/0
    5      S         0            1     -  watchdog/0
    6      S         0            1     -  migration/1
    7      S         0            1     -  ksoftirqd/1
    8      S         0            1     -  watchdog/1
    9      S         0            1     -  events/0
   10      S         0            1     -  events/1
   11      S         0            1     -  khelper
   12      S         0            1     -  netns

! ---Output omited for brevity---

 3431      S  41520eb8            1     -  fex
 3434      S  41523f92            1     -  lldp
 3435      S  415c4642            1     -  netstack
 3471      S  41523f92            1     -  radius
 3472      S  41520eb8            1     -  acllog
 3473      S  41523f92            1     -  cdp
 3475      S  41523f92            1     -  cfs
 3476      S  415c4642            1     -  ecp
 3477      S  415c4642            1     -  igmp

! ---Output omited for brevity---

    -     NR         -            0     -  Flexlink
    -     NR         -            0     -  tacacs
    -     NR         -            0     -  eigrp
    -     NR         -            0     -  isis
    -     NR         -            0     -  isis_otv
    -     NR         -            0     -  ospfv3
    -     NR         -            0     -  rip
    -     NR         -            0     -  eigrp
    -     NR         -            0     -  isis
    -     NR         -            0     -  ospf
    -     NR         -            0     -  ospfv3

! ---Output omited for brevity---

References

Cisco – Enabling or Disabling Features

NX-OS and Cisco Nexus Switching: Next-Generation Data Center Architectures – Process Modularity

Cisco – Nexus 7000 FabricPath

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