Understanding Nexus -- Part 16 -- Configuring IPv4

Today we will have a look at IPv4 addresses and its configuration on NX-OS. We will also look at Address Resolution Protocol (ARP), and Internet Control Message Protocol (ICMP) as these are the supplement protocols for IPv4.
NX-OS supports 2 types of protocols viz, IPv4 and IPv6 as a layer 3 protocol.

IPv4

You can configure an IPv4 address as primary or secondary on a device. An interface can have one primary IP address and multiple secondary addresses. You can specify an unlimited number of secondary addresses.

Note: Packets that are generated by the device always use the primary IPv4 address.

Address Resolution Protocol

Well I am looking for giving any explanation on ARP here. So we will just discuss about the defaults and configs.

By default, ARP timeout is 1500 seconds. And Proxy ARP is disabled.

ICMP

ICMP is an essentical protocol for IP communication. It provides message packets that report errors and other information that is relevant to IP processing
Just to give you some more details,  ICMP redirects are disabled on interfaces where the local proxy ARP feature is enabled.

Configurring  Primary IP

switch# config t
switch(config)# interface ethernet 2/3
switch(config-if)# ip address 192.2.1.1 255.0.0.0

OR

switch(config-if)# ip address 192.2.1.1/8

Configuring Secondary IP

switch(config-if)# ip address 192.2.1.1 255.0.0.0 secondary

Static ARP

switch(config)# interface ethernet 2/3
switch(config-if)# ip arp 192.2.1.1 0019.076c.1a78

Proxy ARP

With Proxy ARP enabled on the Gateway Router, it replies to all ARP request initiated by the Clients/ User machines. The destination IP in the ARP request will be outside of the network (not from the same LAN).

switch(config)# interface ethernet 2/3
switch(config-if)# ip proxy-arp

Local Proxy ARP

When you enable local Proxy ARP, ARP responds to all ARP requests for IP addresses within the subnet and forwards all traffic between hosts in the subnet.

switch(config)# interface ethernet 2/3
switch(config-if)# ip local-proxy-arp

Path MTU Discovery

switch(config)# interface ethernet 2/3
switch(config-if)# ip tcp path-mtu-discovery

IP Packet Verification

NX-OS supports an Intrusion Detection System (IDS) that checks for IP packet verification. You can enable or disable these IDS checks.
Just use the following command in the global config mode and look out for the options ;-)

Switch(config)# hardware ip verify ?