Q. Will you support Cisco switching?

A. Switching is going be supported in GNS3 using L2IOU images, which are special IOS images made to work on PC/Linux. These are more like generic Cisco switches with most of the same features as in real switches. So in the end you can have 90% of the same features, just a bit slower.

Q. Will switching work on Windows or Mac OS X?

A. Currently, L2IOU images work only on Linux or Solaris. On Windows and Mac OS X, the current plan is to use a virtual machine to run L2IOU but we are still looking for an alternative technical solution.

Q. Why not supporting 100% of Cisco switching features?

A. Simply because L2IOU images do not support all of the features, we suspect that some of them require the dedicate hardware found in Cisco devices in order to work, other features are simply buggy in currently available L2IOU versions. The one that are likely not to work are L3 Etherchannel, ISL trunks, DHCP snooping, Private VLAN, SPAN/RSPAN/ERSPAN, Port-security, Voice VLANs, MLS QoS and QinQ.

Q. Will I be able to run IOS-XE?

A. Cisco has released an IOS-XE version that work in VMware and KVM. Actually, you can already use it with GNS3 (please see this newsfor more details) but we want to make it easier.

Q. Will I be able to run NX-OS (Nexus)?

A. Cisco has a version of NX-OS than can run inside VMware ESX/ESXi. So in theory there is a way to use it with GNS3, we do not have more info because our focus is on routing & switching and security.

Q. Will I be able to run IOS-XR?

A. Cisco is planning to release a virtual IOS-XR named XRv early next year. After this release, it should be possible to integrate IOS-XR in GNS3.

Q. Will you provide ways to train for Cisco Data Center and Voice certifications?

A. Our focus is currently on Routing & Switching followed by security but we plan to check what can be technically done for Data Center and Voice in the future.

Q. Will IOS 15.x be supported?

A. IOS 15.x is currently only supported by the Cisco 7200 router in GNS3 but thanks to the IOU (IOS on Unix) integration, more IOS 15.x versions will be supported and with less resources too.

Q. Will you add more Cisco devices like ISR or other platforms?

A. No, the issue is that these devices have specialized hardware impossible or extremely hard to emulate. New Cisco devices will come in the form of VMware/KVM/VirtualBox appliances (see IOS-XE, IOS-XR and NX-OS questions above) and IOU images.

Q. Will Arista’s EOS be supported?

A.One of our user managed to run Arista vEOS within GNS3! See this forum post for more details. So all we need to do is maybe streamline this a bit and here it is, Arista’s EOS platform in GNS3!

Q. Will GNS3 support HP Procurve switches and routers in the future?

A. HP is starting to have some simulation/emulation products out there that can potentially be integrated in GNS3. We also have to see if a partnership is possible with HP. So yes probably in the future but not for the first release of the new GNS3.

• Why my c2600 IOS image doesn’t work with Dynamips/GNS3?
  • Images for 2600 routers must be uncompressed to work.
• Why my serial connection works though the interfaces are both DCE?
  • GNS3/Dynamips doesn’t emulate the physical layer which is why the serial connections work even though they are both DCE.
• Is IOS version 15.0 supported?
  • 7206VXR is the only emulated router that supports this IOS. Please also note Cisco stated that only IOS 15.n(n)M releases will be supported on Cisco 7200 series routers.

Cisco 1700 Series

1700s have one or more interfaces on the motherboard, 2 subslots for WICs (excepting on 1710s), an no NM slots.

1710

• 1 FastEthernet and 1 Ethernet fixed ports (CISCO1710-MB-1FE-1E).
• WIC slots: 0
• Note that interfaces do not use a slot designation (e.g. “f0”)

1720, 1721 and 1750

• 1 FastEthernet fixed port (C1700-MB-1ETH).
• WIC slots: 2 (maximum of 2 Ethernet ports or 4 serial ports).
• Note that interfaces do not use a slot designation (e.g. “f0”)

1751 and 1760

• 1 FastEthernet fixed port (C1700-MB-1ETH).
• WIC slots: 2 (maximum of 2 Ethernet ports or 4 serial ports).

WIC cards

• WIC-1T (1 serial port)
• WIC-2T (2 serial ports)
• WIC-1ENET (1 Ethernet ports)

Cisco 2600 Series

2600s have one or more interfaces on the motherboard, 2 subslots for WICs and 1 Network Module (NM) slot.

2610

• 1 Ethernet fixed port (CISCO2600-MB-1E).
• NM slots: 1 (maximum of 4 Ethernet ports or 16 FastEthernet ports).
• WIC slots: 3 (maximum of 6 serial ports).

2611

• 2 Ethernet fixed ports (CISCO2600-MB-2E).
• NM slots: 1 (maximum of 4 Ethernet ports or 16 FastEthernet ports).
• WIC slots: 3 (maximum of 6 serial ports).

2610XM, 2620, 2620XM and 2650XM

• 1 FastEthernet fixed port (CISCO2600-MB-1FE).
• NM slots: 1 (maximum of 4 Ethernet ports or 16 FastEthernet ports).
• WIC slots: 3 (maximum of 6 serial ports).

2611XM, 2621, 2621XM and 2651XM

• 2 FastEthernet fixed ports (CISCO2600-MB-2FE).
• NM slots: 1 (maximum of 4 Ethernet ports or 16 FastEthernet ports).
• WIC slots: 3 (maximum of 6 serial ports).

Network Modules

• NM-1E (1 Ethernet port)
• NM-4E (4 Ethernet ports)
• NM-1FE-TX (1 FastEthernet port)
• NM-16ESW (switch module: 16 FastEthernet ports)
• NM-NAM (Network Analysis Module, not working).
• NM-IDS (IDS Network Module, not working).

WIC cards

• WIC-1T (1 serial port)
• WIC-2T (2 serial ports)

Cisco 3600 Series

3600s have 2 to 6 Network Module (NM) slots.

3620

• NM slots: 2 (maximum of 8 Ethernet ports, 32 FastEthernet ports or 8 serial ports).

3640

• NM slots: 4 (maximum of 16 Ethernet ports, 32 FastEthernet ports or 16 serial ports).

3660

• 2 FastEthernet fixed ports (Leopard-2FE).
• NM slots: 6 (maximum of 24 Ethernet ports, 32 FastEthernet ports or 24 serial ports).

Network Modules

• NM-1E (1 Ethernet port)
• NM-4E (4 Ethernet ports)
• NM-1FE-TX (1 FastEthernet port)
• NM-16ESW (switch module: 16 FastEthernet ports, maximum of 2 modules per router)
• NM-4T (4 serial ports)

Cisco 3700 Series

3700s have 2 FastEthernet interfaces on the motherboard, 3 subslots for WICs and 1 to 4 Network Module (NM) slots.

2691

• 2 FastEthernet fixed ports (GT96100-FE)
• NM slots: 1 (maximum of 16 FastEthernet ports or 4 serial ports).
• WIC slots: 3 (maximum of 6 serial ports).
• Note: the 2691 is essentially a 3700 with 1 NM slot.

3725

• 2 FastEthernet fixed ports (GT96100-FE)
• NM slots: 2 (maximum of 32 FastEthernet ports or 8 serial ports).
• WIC slots: 3 (maximum of 6 serial ports).

3745

• 2 FastEthernet fixed ports (GT96100-FE)
• NM slots: 4 (maximum of 32 FastEthernet ports or 16 serial ports).
• WIC slots: 3 (maximum of 6 serial ports).

Network Modules

• NM-1FE-TX (1 FastEthernet port)
• NM-16ESW (switch module: 16 FastEthernet ports, maximum of 2 modules per router)
• NM-4T (4 serial ports)
• NM-NAM (Network Analysis Module, not working).
• NM-IDS (IDS Network Module, not working).

WIC cards

• WIC-1T (1 serial port)
• WIC-2T (2 serial ports)

Cisco 7200 Series

7200s have a different architecture. Only the 7206 is supported, it has 6 Port Adapters (PA) slots.

7206

• PA slots: 6
• Note: VXR chassis, NPE-400 and C7200-IO-FE are the default in GNS3.

Chassis types

• STD
• VXR

Network Processing Engines (NPEs)

• NPE-100
• NPE-150
• NPE-175
• NPE-200
• NPE-225
• NPE-300
• NPE-400
• NPE-G2 (requires the use of NPE-G2 c7200p IOS images)

Input/Output Controllers

Can be inserted into slot 0 only.

• C7200-IO-FE (1 FastEthernet port)
• C7200-IO-2FE (2 FastEthernet ports)
• C7200-IO-GE-E (1 GigabitEthernet port, Ethernet port is not functional)

Port Adapters

Online Insertion and Removal (OIR) is supported, allowing you to replace PAs while the router is running.

• PA-FE-TX (1 FastEthernet port)
• PA-2FE-TX (2 FastEthernet ports)
• PA-4E (4 Ethernet ports)
• PA-8E (8 Ethernet ports)
• PA-4T+ (4 serial ports)
• PA-8T (8 serial ports)
• PA-A1 (1 ATM port)
• PA-POS-OC3 (1 Packet-Over-SONET port)
• PA-GE (1 GigabitEthernet port)

Cisco Catalyst Switches

At this moment, it is not possible to emulate Catalyst switches with Dynamips/GNS3. This is due to the impossibility to emulate ASIC processors used in those type of devices. However you can use the EtherSwitch module with 2600s, 3600s and 3700s Series. Keep in mind that this module works differently (uses the vlan database etc.) and doesn’t support the following features:

• Access Switch Device Manager (SDM) Template
• ACL – Improved Merging Algorithm
• ARP Optimization
• BGP Increased Support of Numbered as-path Access Lists to 500
• BGP Restart Neighbor Session After max-prefix Limit Reached
• BGP Route-Map Continue Support for Outbound Policy
• Clear Counters Per Port
• DHCP Snooping
• DHCP Snooping Counters
• Diagnotics Options on bootup
• ErrDisable Reactivation Per Port
• ErrDisable timeout
• EtherChannel – Flexible PAgP
• Etherchannel Guard
• Fallback Bridging
• Flex Link Bi-directional Fast Convergence
• Flex Link VLAN Load-Balancing
• Flex Links Interface Preemption
• GOLD – Generic Online Diagnostics
• IEEE 802.1ab, Link Layer Discovery Protocol
• IEEE 802.1s – Multiple Spanning Tree (MST) Standard Compliance
• IEEE 802.1s VLAN Multiple Spanning Trees
• IEEE 802.1t
• IEEE 802.1W Spanning Tree Rapid Reconfiguration
• IEEE 802.1x – Auth Fail Open
• IEEE 802.1x – Auth Fail VLAN
• IEEE 802.1x – VLAN Assignment
• IEEE 802.1x – Wake on LAN Support
• IEEE 802.1X Multi-Domain Authentication
• IEEE 802.1x RADIUS Accounting
• IEEE 802.1x with Port Security
• IEEE 802.3ad Link Aggregation (LACP)
• IEEE 802.3af Power over Ethernet
• IGMP Fast Leave
• IGMP Version 1
• IGRP
• IP Phone Detection Enhancements
• IP Phone Enhancement – PHY Loop Detection
• IPSG (IP Source Guard)
• Jumbo Frames
• L2PT – Layer 2 Protocol Tunneling
• MAC Authentication Bypass
• MLD Snooping
• Multicast Etherchannel Load Balancing
• NAC – L2 IEEE 802.1x
• NAC – L2 IP
• NAC – L2 IP with Auth Fail Open
• Packet-Based Storm Control
• Per Port Per VLAN Policing
• Port Security
• Port Security on Private VLAN Ports
• Private VLANs
• QoS Policy Propagation via Border Gateway Protocol (QPPB)
• Rapid-Per-VLAN-Spanning Tree (Rapid-PVST)
• Reduced MAC Address Usage
• Remote SPAN (RSPAN)
• Smart Port
• Spanning Tree Protocol (STP) – Loop Guard
• Spanning Tree Protocol (STP) – PortFast BPDU Filtering
• Spanning Tree Protocol (STP) – Portfast Support for Trunks
• Spanning Tree Protocol (STP) – Root Guard
• Spanning Tree Protocol (STP) – Uplink Load Balancing
• SRR (Shaped Round Robin)
• Standby Supervisor Port Usage
• STP Syslog Messages
• Switching Database Manager (SDM)
• Trunk Failover
• Trusted boundary (extended trust for CDP devices)
• Unicast Mac Filtering
• UniDirectional Link Detection (UDLD)
• VLAN Access Control List (VACL)
• VLAN Aware Port Security
• Weighted Tail Drop (WTD)

Cisco PIX firewalls

A special version of Qemu called PEMU is embedded into GNS3 for emulating the PIX 525 Security Appliance. PIX software up to version 7.2(4) is supported.

Cisco ASA firewalls

Qemu/GNS3 emulates ASA5520 (ASA 5520 Series Adaptive Security Appliance) hardware to run ASA software up to version 8.0(2).

Cisco IDS sensors

Qemu/GNS3 emulates an IDS 4235/4215 Sensor. The software IPS is known to run with release 6.0.

Juniper routers

JunOS, the Operating System for Juniper routers is based on FreeBSD, an UNIX Operating System that runs on PCs. At this date JunOS versions for Juniper M series are known to work in GNS3.

Hosts

Thanks to Qemu and VirtualBox, GNS3 can run many operating systems like Linux or Windows as well as a lot of appliances. To save you time, we provide ready-to-use Qemu and VirtualBox images that integrate Linux Microcore (command line) and Linux Tinycore (small graphical interface). These images are designed to not use much memory, allowing you to run many virtual hosts. They include the following tools and features:

• Console support
• IPv6 support
• iperf, tcpdump, iproute2 and iptables
• SSH and telnet servers
• D-ITG (Distributed Internet Traffic Generator)

Performance

Dynamips/GNS3 uses a fair amount of RAM and CPU in order to accomplish its emulation magic. Instructions can be found in the user documentation to reduce this but you may also consider the following advices:

• Use c36xx, c37xx or c7200 IOS images. They are usually more stable with Dynamips.
• Run Dynamips/GNS3 on Linux or Mac OS X if you can, performance is better and Dynamips is far more stable.
• Try to not use the latest IOS images, for instance versions >= 12.4, depending of the IOS features you want, running 12.3 or 12.2 versions requires a lot less memory and CPU.

Of course, the number of routers you can run at the same time also strongly depend of your amount of RAM and CPU. On average users can run 10 to 15 routers with routing protocols configured without any problem. Some have even ran more than 100 routers on the same PC.