How to configure Dynamips template preferences

Dynamips is the engine in GNS3 that uses IOS images to simulate Cisco routers. Unlike built-in templates, Dynamips IOS router templates need to be created by the user. You must select the IOS image, choose the platform, configure slots, and so on.

Supported Platforms (7 types)

Platform	Models	RAM (default)	NVRAM	Special fields
c7200	7200 series	512 MB	512 KB	npe, midplane
c3745	3745	256 MB	256 KB	--
c3725	3725	128 MB	256 KB	--
c3600	3620 / 3640 / 3660	192 MB	128 KB	chassis
c2691	2691	192 MB	256 KB	--
c2600	2610~2651XM and more chassis	160 MB	128 KB	chassis
c1700	1720~1760	160 MB	128 KB	chassis

Create a Template

note

Different platforms support different Network Adapters. Please choose based on your device.

1. Click the "Dynamips" option to enter.

   

2. Click the + button at the top right to add a new template.

   

3. Follow the wizard steps. Click "IOS Image".

   

4. In the IOS Image step, click "Click to add image" to upload a local image file, or choose an already uploaded image from the list below. Then click "Name and platform".

   

5. In Name and platform, enter the name and choose the platform. Then click "Memory".

   

6. In Memory, you can change the RAM size. The default values are fine. Then click "Network adapters".

   

7. In Network adapters, select the interface cards for the template. Then click "Idle-PC".

   

8. Click the "Idle-PC finder" button to calculate the Idle-PC value. This value helps reduce CPU usage.

   

9. After the calculation is done, click the "Add Template" button.

   

10. After creation, you can see the new template in the list.

    

11. Click the three-dot button on the right to choose Delete, Copy, or Edit.

    

IOS Router Template Configuration Details

Click the "Edit" button to enter the configuration details.

General Settings (c7200)

Here are all the fields in the General settings area of the IOS router template configuration page and what they do:

Field	Type	Default	Use
Template name	Text	Required, no default	Name of the template, shown in the list
Default name format	Text	R{0}	Auto-naming format for instances. {0} is an increasing number
Category	Dropdown	router	Category for grouping in the device panel
Symbol	Text + button	router	Icon shown on the topology
Platform	Read-only	c7200 (cannot change after creation)	Platform name
Chassis	Read-only	Not applicable	c7200 has no chassis option
Tags	Chip input	[]	Tags for sorting/filtering
IOS image path	Text	Required, no default	Path to the IOS image file
Initial startup-config	Text	ios_base_startup-config.txt	Startup configuration file
Initial private-config	Text	"" (empty)	Private configuration file
Console type	Dropdown	telnet	Options: telnet / vnc / spice / none
Auxiliary console type	Dropdown	none	Auxiliary console type
Auto start console	Checkbox	False	Automatically opens the console when enabled

note

For example, on Cisco IOS devices, you need to add a device_type tag so that AI Copilot can recognize the device type, for example device_type:cisco_ios_telnet. Without the correct tag, AI Copilot cannot work with this device.

Special notes about c7200:

• c7200 has no Chassis option (unlike c1700/c2600/c3600), so Chassis is not shown in General settings
• c7200 network adapters are configured in the Slots area
• When Console type is set to vnc or spice, the server needs VNC/SPICE support to work correctly

Memories and Disks

This area has two parts: Memory and Disk.

Memory

Field	Type	Unit	Template default	Compute actual value	Use
RAM size	Number input	MB	512	256	Memory for the router
NVRAM size	Number input	KB	512	128	Non-volatile RAM, stores startup-config
I/O memory	Number input	%	Not applicable	--	c7200 does not have this field. Managed by Slot 0 IO controller

Disk

Field	Type	Unit	Template default	Compute actual value	Use
PCMCIA disk0	Number input	MB	0	64	ATA flash disk0 size. Set to 0 to disable
PCMCIA disk1	Number input	MB	0	0	Second storage device

note

Template default values are not the same as the actual Dynamips process defaults. The template gives recommended values. The compute side has the hard defaults from Dynamips.

Special notes about c7200:

• c7200 does not show the I/O memory field. I/O memory is managed by the IO controller card selected in Slot 0
• PCMCIA disk0/disk1 match the real router's disk0: and disk1:. c7200 usually needs at least disk0 to start IOS
• There is a checkbox "Automatically delete NVRAM and disk files" at the bottom. When checked, NVRAM and disk files are cleaned up when the project is deleted

Slots (c7200)

c7200 simulates a 7206 router. It has 7 slots (0-6). Slot 0 is the IO controller (single choice). Slots 1-6 are port adapters (can choose multiple, can be empty).

Slot	Available adapters	Description
Slot 0	C7200-IO-FE, C7200-IO-2FE, C7200-IO-GE-E	IO controller. Provides out-of-band management interface. 1 or 2 Fast Ethernet ports, or 1 Gigabit port
Slots 1-6	PA-A1	ATM adapter, for ATM network interfaces
	PA-FE-TX	Single port Fast Ethernet
	PA-2FE-TX	Dual port Fast Ethernet
	PA-GE	Single port Gigabit Ethernet
	PA-4T+	4-port serial (enhanced)
	PA-8T	8-port serial
	PA-4E	4-port Ethernet
	PA-8E	8-port Ethernet
	PA-POS-OC3	Packet-over-SONET OC3 interface

Behavior:

• Slot 0: only one IO controller can be selected (no empty option)
• Slots 1-6: multiple choices allowed, can be left empty
• Template defaults: Slot 0 -> None, Slots 1-6 -> None (all empty at template level). The client UI may fill in the first available option automatically
• c7200 has no WIC slots. WIC functions are provided by the Slot 0 IO controller

Advanced Settings (c7200)

Field	Type	Default	Use
System ID	Text	FTX0945W0MY	Cisco router System ID, used to unlock feature sets
Base MAC	Text (format xxxx.xxxx.xxxx)	"" (empty)	Base MAC address. If empty, the server assigns one automatically
Idle-PC	Text (hex 0x...)	"" (empty)	Key parameter to lower CPU usage. Detected with Idle-PC finder
Idlemax	Number	500	Idle detection parameter, controls max CPU time slice
Idlesleep	Number	30	Sleep time per idle cycle (microseconds)
Exec area	Number	64	JIT compiler execution area size
Enable mmap support	Checkbox	True	Enables memory-mapped file support
Enable sparse memory support	Checkbox	True	Sparse memory support, enabled by default on c7200

Important notes for c7200:

• Idle-PC is required for c7200. Without it, the host CPU will stay at 100%
• mmap and sparsemem: for c7200 with 512 MB RAM or more, it is recommended to enable both
• c7200 may need more conservative Idlemax and Idlesleep values than lower-end platforms