Quick question - I was learning about subinterfaces and using Cisco Packet Tracer I wanted to create simple network with two computers (every in different networks ( and and different VLAN) and using one router connect them. So my problem is that when I was typing the network R1(config-subif)#ip address wasn't working while R1(config-subif)#ip address was working. I'm just curious why there is there difference because both and will give - host adresses.

Edit: So to be more precise I was just pinging two computers and there was "Request timed out" message. enter image description here

  • 1
    wasn't working isn't descriptive. You need to edit your question to explain it, and you need to include the exact message, if any, that you got.
    – Ron Maupin
    Commented Dec 13, 2016 at 19:27
  • @RonMaupin Ok, I've updated the question with more info.
    – mikro098
    Commented Dec 13, 2016 at 19:47
  • Please provide configurations of the switch and the router, without that it's only guessing.
    – Teun Vink
    Commented Dec 13, 2016 at 19:50
  • OK, we are starting to get somewhere. It sounds like PC0 has its gateway as You should really include all the relevant information, including the router and switch configurations.
    – Ron Maupin
    Commented Dec 13, 2016 at 19:50
  • Well if PC0 has address then you cannot configure that same address on the router a well.
    – hertitu
    Commented Dec 13, 2016 at 20:22

3 Answers 3


Besides on what was already mentioned, just to answer your question, it looks like you are trying to setup an IP address in the router which already belongs to PC0. Take a look and notice as they are the same - and you might know that two devices can not have the same IP address.


Default gateway missing on PC's.

Your hosts/endpoints need to have a default gateway in addition to an IP address. Without the default gateway, the endpoint don't know how/where to send the packet for the other subnet. The default gateway is going to be on the same subnet as the PC's NIC card.


R1(config-subif)#ip address wasn't working while R1(config-subif)#ip address was working.

This should work . When creating sub interfàce with IPaddress . This ip address act as default gateway for this Vlans . But make sure you assign another ip address to Pc ,assign to PC0 .

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