asked on

Switchport mode trunk in GNS3

Hi, I am testing the GNS3 with switching module. I test with cisco 3725/3640/3660 to simulate a switch but when I entered "conf t" mode, it cannot have the "switchport mode " command, why?

Does anyone know any better way to simulate a switch? I knew Packet tracer but sadly, it does not support many model of ASA (but GNS3 does) which I need to play with Switches

Predrag Jovic

You can never have switchport mode in global configuration.
You need in configuration add switching module (right click on device - configure - Slot (1 or 2) - NM-16ESW) and than under interfaces of that specific card slot you will be able to issue - switchport module.
Also, VLANs should be created in VLAN database - not with VLAN command...

en
vlan database
% Warning: It is recommended to configure VLAN from config mode,
  as VLAN database mode is being deprecated. Please consult user
  documentation for configuring VTP/VLAN in config mode.
vlan 10 name OFFICE
exit
conf t
Enter configuration commands, one per line.  End with CNTL/Z.
int fa2/1
switchport mode
switchport mode ?
  access  Set trunking mode to ACCESS unconditionally
  trunk   Set trunking mode to TRUNK unconditionally

Open in new window

Switching does not have good support in GNS3. I am using UNL for switching (now renamed to EVE-NG).

DP230

ASKER

I followed your instructions but did not help:

ESW1#vlan database
ESW1(vlan)#vlan 10 name OFFICE
VLAN 10 added:
Name: OFFICE
ESW1(vlan)#exit
APPLY completed.
Exiting....
ESW1#
ESW1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
ESW1(config)#int f0/0
ESW1(config-if)#switchport mode trunk
^
% Invalid input detected at '^' marker.

------------------
ESW1#show version
Cisco IOS Software, 3600 Software (C3660-JK9O3S-M), Version 12.4(25d), RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Wed 18-Aug-10 07:31 by prod_rel_team

ROM: ROMMON Emulation Microcode
ROM: 3600 Software (C3660-JK9O3S-M), Version 12.4(25d), RELEASE SOFTWARE (fc1)

Yes, I also tried EVE-ng, the same issue persisted, is there any chance for the error in image itself? I tried JunOS, Router OS and they were OK, but switch...;(

ASKER CERTIFIED SOLUTION

Predrag Jovic

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

DP230

ASKER

My bad :) Thank you very much!

Predrag Jovic

You are welcome.

DP230

ASKER

Just another quick question, can Switch Layer 3 connect to ASA Firewall 5515?

We are planning our diagram as below:

PC <--------> Access switches (Cisco SG95) <----------> Core Switch (Cisco 3560) <------------------> ASA 5515 <-----------> Internet

Is it possible, can you please suggest?

Predrag Jovic

Not sure what ASAs are supported in GNS3, but if 5515 is supported can be done.
ASAv is recommended.
IOSvL2 is recommended for switching.
Those 2 recommended are Cisco images for VIRL.

I don't think that 3560 is among recommended IOS images for routers. I am using 3725 recommended image.
List of IOS recommend router images.