if you’re not accustomed to reading release notes for your favorite platform (Nexus NX-OS in this case), probably you already overlooked that starting with 10.1(2) there’s 2-stage commit system, known from IOS XR.
what does that mean, really? that doing changes over CLI, directly in the parser, you can edit/add/remove whole blocks of configuration before committing them to running/actual configuration. so in case when you edit interface IP addressing (always touchy moment, specially for devices you’re 300km away for example) the session could look like this:
nxos10# configure dual-stage Enter configuration commands, one per line. End with CNTL/Z. nxos10(config-dual-stage)# interface vlan 888 nxos10(config-dual-stage-if)# ip address 192.168.88.1/24 nxos10(config-dual-stage-if)# no shut nxos10(config-dual-stage-if)# [and rest of the interface configuration] ! let's double-check we don't have this VLAN yet in configuration ! at this point: nxos10(config-dual-stage-if)# do sh ip int brief IP Interface Status for VRF "default"(1) Interface IP Address Interface Status Vlan33 192.168.33.1 protocol-up/link-up/admin-up Vlan66 192.168.66.1 protocol-up/link-up/admin-up Vlan555 192.168.55.1 protocol-up/link-up/admin-up Vlan999 192.168.99.1 protocol-up/link-up/admin-up ! now, let's commit the changes we did nxos10(config-dual-stage-if)# commit Verification Succeeded. Proceeding to apply configuration. This might take a while depending on amount of configuration in buffer. Please avoid other configuration changes during this time. Configuration committed by user 'cisco' using Commit ID : 1000000001 ! ...and the interface is already in the config: nxos10(config-dual-stage)# do sh ip int brief IP Interface Status for VRF "default"(1) Interface IP Address Interface Status Vlan33 192.168.33.1 protocol-up/link-up/admin-up Vlan66 192.168.66.1 protocol-up/link-up/admin-up Vlan555 192.168.55.1 protocol-up/link-up/admin-up Vlan888 192.168.88.1 protocol-up/link-up/admin-up Vlan999 192.168.99.1 protocol-up/link-up/admin-up
obviously, you can also roll back to the specific commit configuration, as every commit has it’s own ID:
nxos10# rollback configuration to 1000000001
you can also check changes for specific commit by its ID:
nxos10# show configuration commit changes 1000000001 *** /bootflash/.dual-stage/1000000001.tmp Mon Jul 12 17:14:49 2021 --- /bootflash/.dual-stage/1000000001 Mon Jul 12 17:14:51 2021 *************** *** 535,540 **** --- 535,543 ---- + interface Vlan888 + ip address 184.108.40.206/24 +
and during configuration session, you can also check what’s currently in the session before you commit it to running config (to double-check if we didn’t make any errors/typos):
nxos10(config-dual-stage-if)# show configuration ! Cached configuration ! interface Vlan888 no ip unreachables no shutdown ip redirects
right now, NX-OS 2-stage commit is not as rich and extended as IOS XR one, but it’s great to see that significant enhancement in OS existing for extended period of time already.
happy committing :)