Creating sub interfaces on 3650

Regalis01 · ‎02-07-2016

HI,

I am trying to configure a tagged routed port on an interface of a 3650 running IOS 12.2. I do not seem to have the 'encapsulation' option and get this error when trying to add an IP address:

interface FastEthernet0/1
description sw2 fa0/1
no switchport
no ip address
end

sw1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
sw1(config)#int fa0/1.10
sw1(config-subif)#ip address 10.0.1.1 255.255.255.0

% Configuring IP routing on a LAN subinterface is only allowed if that
subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q,
or ISL vLAN.

sw1(config-subif)#?
Interface configuration commands:
arp             Set arp type (arpa, probe, snap) or timeout
bandwidth       Set bandwidth informational parameter
bgp-policy      Apply policy propogated by bgp community string
cdp             CDP interface subcommands
default         Set a command to its defaults
delay           Specify interface throughput delay
description     Interface specific description
exit            Exit from interface configuration mode
ip              Interface Internet Protocol config commands
logging         Configure logging for interface
no              Negate a command or set its defaults
ntp             Configure NTP
priority-queue Priority Queue
queue-set       Choose a queue set for this queue
rate-limit      Rate Limit
service-policy Configure QoS Service Policy
shutdown        Shutdown the selected interface
srr-queue       Configure shaped round-robin transmit queues
standby         HSRP interface configuration commands
timeout         Define timeout values for this interface

Could someone please tell me how I configure a port to accept traffic on VLAN 10 on a routed port?

Boris Uskov · ‎02-08-2016

Hello,

you can make FastEthernet0/1 switchport and configure it as trunk. For example:

vlan 10
 exit
vlan20
 exit
interface FastEthernet0/1
 switchport
 switchport trunk encapsulation dot1q
 swithcport mode trunk

After that, in order to be able to route traffic from one vlan to another, you need to create Swith virtual interfaces (SVI). For example:

interface vlan 10
 ip address 192.168.10.1 255.255.255.0
interface vlan 20 
 ip address 192.168.20.1 255.255.255.0

In this case, SVIs will act as subinterfaces on router, so you can use them as default gateways for LANs.

FastEthernet 0/1 in mode trunk will get a possibility to accept traffic from all configured vlans, ussing 802.1Q tags.

For more information about SVIs, please, see the following link:

https://learningnetwork.cisco.com/thread/62241