Configuring the NEC Switch

Although configuring the NEC switch is pretty intuitive if you have worked with Cisco switches, some aspects of configuring them might require digging through the Japanese manuals to find. Here is a list of configurations that I have dug through the manuals for so you don't have to.

Overview

All configuration steps assume privileged mode. [BR] The configuration for the following topics are covered here:

• Undoing configurations
• Trunks
• Native VLANs
• Switch as DHCP client

Undoing Configurations

Most of the time, just adding the command no to the beginning of what you see when you do the command show configuration will suffice for undoing configurations, but occasionally you get something like this:

(config)# no vlan 4
vlan : Can't delete this configuration referred by other configuration.

This happens when the configs for an interface that you are trying to delete are associated with something else; you need to undo any configurations associated with an interface before you can delete it. In this particular case, VLAN 4 is associated with port 0/27, and you need to undo the configurations to port 0/27 that have to do with vlan 4 before you can get rid of it.

!(config)# int gi 0/27
!(config-if)# sh
interface gigabitethernet 0/27
  switchport mode access
  switchport access vlan 4
!
!(config-if)# no sw acc vlan 4
!(config-if)# exit
!(config)# no vlan 4
!(config)# 

Native VLANs

1. Make a VLAN. Name the native VLAN.

   (config)# vlan 1
   (config-vlan)# name "Network"
   !(config-vlan)# exit
   

2. Assign static IP address to the interface. we needed to find the switch's IP address

   !(config-vlan)# interface vlan 1
   !(config-if)# ip address 172.16.19.253 255.255.0.0
   

3. Configure ports to be trunk ports, then specify the native VLAN

   !(config)# interface gi 0/48
   !(config-if)# switchport mode trunk 
   !(config-if)# switchport trunk native vlan 1
   

4. Specify which VLANs are allowed on the trunk. This includes all VLANs that converge to this trunk, as well as the native VLAN for this trunk. If the port is already made to allow other VLANs, instead of using command switchport trunk allowed vlan 1,3,27,28 you can just add VLAN 1 by using the vlan add <vlan ID> context:

   !(config-if)# swi trunk allowed vlan add 1
   

so now the configurations for port 0/48 look like this:

!(config-if)# sh
interface gigabitethernet 0/48
  switchport mode trunk
  switchport trunk allowed vlan 1,3,27-28
  switchport trunk native vlan 1
!