Unable to create subinterface

Unanswered Question

I'm trying to route between 2 VLANs using a C1760 with a WIC-4ESW installed.

When I try to create a subinterface I get the following error:

Router(config)#interface fastEthernet 0/2.1


% Invalid input detected at '^' marker.

(It doesn't show in this forum but the ^ is under the 'f' of 'fastethernet')

I'm able to configure the fastethernet 0/2 interface but it just won't add a subinterface on that port. Is there a problem with the syntax?

Here's a show version:

Router#sho ver

Cisco Internetwork Operating System Software

IOS (tm) C1700 Software (C1700-K9O3SV8Y7-M), Version 12.3(2)XC, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

Synched to technology version 12.3(1.6)T

TAC Support: http://www.cisco.com/tac

Copyright (c) 1986-2003 by cisco Systems, Inc.

Compiled Thu 25-Sep-03 04:18 by ealyon

Image text-base: 0x80008120, data-base: 0x819D753C

ROM: System Bootstrap, Version 12.2(7r)XM2, RELEASE SOFTWARE (fc1)

ROM: C1700 Software (C1700-K9O3SV8Y7-M), Version 12.3(2)XC, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

Router uptime is 9 weeks, 4 days, 16 hours, 48 minutes

System returned to ROM by power-on

System image file is "flash:c1700xc.bin"

cisco 1760 (MPC860P) processor (revision 0x500) with 114688K/16384K bytes of memory.

Processor board ID FOC07460LQF (3260012057), with hardware revision 0000

MPC860P processor: part number 5, mask 2

Bridging software.

X.25 software, Version 3.0.0.

1 Ethernet/IEEE 802.3 interface(s)

5 FastEthernet/IEEE 802.3 interface(s)

1 Virtual Private Network (VPN) Module(s)

32K bytes of non-volatile configuration memory.

32768K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
sundar.palaniappan Thu, 05/03/2007 - 15:12
User Badges:
  • Green, 3000 points or more


Your configuration isn't the problem. You probably aren't using the right IOS image that supports router-on-a-stick. You need at least an IP Plus feature set IOS for this function.



Amit Singh Fri, 05/04/2007 - 05:57
User Badges:
  • Cisco Employee,


I agree with Glen on this.You cannot create routed ports or sub-interfaces on the HWIC-4ESW Card. This is not supported on the card. This is a pure L2 switch, you cannot configure routed port features on it.The way it works is that you have to configure SVI's on this card for inter-vlan routing between the ports. Please see the Q&A below for the feature support:


Please see the configuration guide ofr this card:



-amit Singh


This Discussion