How many VLAN possible to assign to a router port

[microfeel]

For example I have a border router with two ports, first port is wan port and another port is lan port.

How many VLANs possible to assign to a router port?

[InayathUlla Sharieff]

Hi Bot,

Sorry if I have misunderstood your question. As far my knowledge you cannot assign the vlans on the router.

We use the concept of intervlan routing or router on a stick.

More details on https://supportforums.cisco.com/thread/2048618

Vlan on Router:

A vlan configuration on a router is slightly different than on a switch.  On a switch, you would create the vlan and then the routed vlan interface.

On a router you tie a vlan to a subinterface.  You need to create the subinterface and then do the encapsulation dot1q command.  This command basically assigned the vlan to the subinterface.  In this example, there are 2 vlans, vlan 100 and 201.  On the eth 0/0 interface, I created two subinterfaces.  fastethernet0/0.100 and f0/0.201.  Notice that I matched the subinterface number with the vlan ID.  You do not have to do this, but it is a best practice and really helps you as the administrator keep things organized.  So, under f0/0.100, there is the encapsulation dot1q 100, which basically binds vlan 100 to subinterface f0/0.100, then I assigned the IP.  The same is for the other subinterface.  So the router is trunking two vlans on its f0/0 interface, vlan's 100 and 201.

interface FastEthernet0/0
no ip address
speed 100
full-duplex
!
interface FastEthernet0/0.100
description test Network
encapsulation dot1Q 100
ip address 192.168.102.1 255.255.255.128
no snmp trap link-status
!
interface FastEthernet0/0.201
description  Office
encapsulation dot1Q 201
ip address 205.127.102.129 255.255.255.128
no snmp trap link-status

Please feel free to provide some more details on what exactly you are looking if the above link doenst solve your purpose.

HTH

REgards

Inayath

*Plz rate all usefull posts.

[microfeel]

Hi Inayath,

I understud from your words there is hardware restriction.

Is there another restriction for VLAN assignments to a router ports?

[InayathUlla Sharieff]

Hi Bot,

I dont see any restriction for vlan assignments to a router ports.

HTH

Regards

Inayath

[microfeel]

Hi Inayath,

I saw a design of network like  below

ISP <--> [fastethernet0/1]SWITCH1[fastethernet0/2]<--> ROUTER<--> SWITCH2

When I asked about the SWITCH1 purpose on the scheme I was told the purpose of the SWITCH1 to terminate VLANs.

So why I asked that question.

Regards

Bot

[InayathUlla Sharieff · Accepted solution]

Hi Bot,

I am not sure for what purpose this designed was represented.

They could have just directly terminted the ISP to router then followed by switch will solve the purpose.

HTH

Regards

Inayath

[Ravi Singh]

Hello Bot,

It's totally depends upon sub interfaces which you can create for a particular port. because you can assign one interface to one VLan at one time.