Allied Telesis manual Application Example, Vlan example on AT-WR4500 Routers, Name MTU ARP

76	AT-WR4500 Series - IEEE 802.11abgh Outdoor Wireless Routers
	RouterOS v3 Configuration and User Guide

reply-only- the interface will only reply to the requests for to its own IP addresses, but neighbor MAC addresses will be gathered from /ip arp statically set table only

interface (name) - physical interface to the network where the VLAN is put mtu (integer; default: 1500) - Maximum Transmission Unit

name (name) - interface name for reference

vlan-id(integer; default: 1) - Virtual LAN identifier or tag that is used to distinguish VLANs. Must be equal for all computers that belong to the same VLAN.

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MTU should be set to 1500 bytes as on Ethernet interfaces. But this may not work with some Ethernet interfaces that do not support receiving/transmitting of full size Ethernet packets with VLAN header added (1500 bytes data + 4 bytes VLAN header + 14 bytes Ethernet header). In this situation MTU 1496 can be used, but note that this will cause packet fragmentation if larger packets have to be sent over interface. At the same time remember that MTU 1496 may cause problems if path MTU discovery is not working properly between source and destination.

Example

To add and enable a VLAN interface named test with vlan-id=1 on interface ether1:

[admin@AT-WR4562] interface vlan> add name=test vlan-id=1 interface=ether1

[admin@AT-WR4562] interface vlan> print
Flags: X - disabled, R - running
#	NAME	MTU	ARP	VLAN-ID INTERFACE
0 X	test	1500	enabled	1	ether1
[admin@AT-WR4562] interface vlan> enable 0
[admin@AT-WR4562] interface vlan> print
Flags: X - disabled, R - running
#	NAME	MTU	ARP	VLAN-ID INTERFACE
0	R test	1500	enabled	1	ether1

[admin@AT-WR4562] interface vlan>

4.4.3 Application Example

VLAN example on AT-WR4500 Routers

Let us assume that we have two or more RouterOS routers connected with a hub. Interfaces to the physical network, where VLAN is to be created is ether1 for all of them (it is needed only for example simplification, it is NOT a must).

To connect computers through VLAN they must be connected physically and unique IP addresses should be assigned them so that they could ping each other. Then on each of them the VLAN interface should be created:

[admin@AT-WR4562] interface vlan> add name=test vlan-id=32 interface=ether1

[admin@AT-WR4562] interface vlan> print
Flags: X - disabled, R - running
#	NAME	MTU	ARP	VLAN-ID INTERFACE
0	R test	1500	enabled	32	ether1

[admin@AT-WR4562] interface vlan>

If the interfaces were successfully created, both of them will be running. If computers are connected incorrectly (through network device that does not retransmit or forward VLAN packets), either both or one of the interfaces will not be running.

When the interface is running, IP addresses can be assigned to the VLAN interfaces.