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.
The following IPv4 and IPv6 behaviors are applicable to netdevices configured on the Cisco Nexus 3400-S: