Nexus Features and Feature-Sets
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.
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.
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 uninstalledFeature-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.
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---