Starting with the NX-OS 9.2(2) release, netdevices representing the front channel port interfaces are always in the ADMIN
UP state. The final, effective state is determined by the link carrier state.
The following example shows the following interfaces in NX-OS, where eth1/17 is shown as up and eth1/1 is shown as down:
root@kstack-switch# sh int ethernet 1/17 brief
Eth1/17 -- eth routed up none 1000(D) –
root@kstack-switch# sh int ethernet 1/1 brief
Eth1/1 -- eth routed down Link not connected auto(D) –
The following example shows these same interfaces, but this time as shown in the Bash shell using the ip link show command:
bash-4.3# ip link show Eth1-17
49: Eth1-17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 100
link/ether 00:42:68:58:f8:eb brd ff:ff:ff:ff:ff:ff
bash-4.3# ip link show Eth1-1
33: Eth1-1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 100
link/ether 00:42:68:58:f8:eb brd ff:ff:ff:ff:ff:ff
In this example, Eth1-1 is shown as being UP, but is shown as NO-CARRIER and state DOWN.
The following example shows these same interfaces, but this time as shown in the Bash shell using the ifconfig command:
bash-4.3# ifconfig Eth1-17
Eth1-17 Link encap:Ethernet HWaddr 00:42:68:58:f8:eb
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:7388 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 B) TX bytes:1869164 (1.7 MiB)
bash-4.3# ifconfig Eth1-1
Eth1-1 Link encap:Ethernet HWaddr 00:42:68:58:f8:eb
inet addr:99.1.1.1 Bcast:99.1.1.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
The output from the ifconfig command provides different information, where the RUNNING keyword is used to represent the final state. By default, all netdevices show the keyword UP, which represents the ADMIN state of the netdevice in the kernel.
Following are the changes that are part of the NX-OS 9.2(2) release:
-
IPv4 address on netdevices — Before the NX-OS 9.2(2) release, the IPv4 address would be plumbed to the netdevice in the kernel even when the corresponding
interface in NX-OS was in the DOWN state. Starting with the NX-OS 9.2(2) release, the IPv4 address are plumbed to the kernel space only when the interface is
in the UP state. Once plumbed, the IPv4 address continues to stay with the netdevice in the kernel even if the interface goes DOWN. It will be removed only after you have entered the following CLI command to explicitly remove the IP address from the NX-OS
interface:
Interface Eth1/1
no ip address IP-address
-
IPv6 address on netdevices — Before the NX-OS 9.2(2) release, the IPv6 address would get flushed from the netdevices in the kernel when the interface
was DOWN. Starting with the NX-OS 9.2(2) release, the netdevices are always in the admin UP state, so the IPv6 addresses will not get flushed from the kernel when the interface goes down.