updated icons

Node icons have been given a face-lift:

Thanks to Justin Y. for suggesting these free-for-any-use icons on the core-dev list, used as the basis for routers and RJ45/tunnel. Inkscape was used to create a rainbow of router icons, along with hub and switch icons to match the routers.

traffic flows using MGEN

A new Traffic Tool has been added to the Tools menu. You can use this tool to create traffic flows between source and destination nodes.
When you click to create or edit a flow, the dialog shown below appears. Clicking on the source node button allows you to choose a node that will send traffic and destination node a node that will listen and log received traffic. IP addresses are automatically entered based on selected nodes, or you can choose addresses from a list. A few preset traffic patterns are defined to help get you started using MGEN.
When the scenario is started, MGEN scripts are generated on each of the nodes. Each flow has a start (and optional stop) time. You can choose to autostart all flows after the emulation is running or manually start and stop them.

To use this feature, you should get MGEN from here. The nightly snapshot for MGEN and protolib are recommended.

distributed emulation with Linux netns

Starting with SVN r133 you can use distributed emulation on Linux for wired networks. For wireless networks (WLANs) you should still use EMANE. GRE tunnels are automatically built between emulation servers.

The Emulation Servers dialog is shown below. This hasn't changed. Be sure to set listenaddr = 0.0.0.0 in your /etc/core/core.conf before starting cored.py (the default listen address is localhost.)

One of the easiest ways to assign nodes to servers is to select a group of nodes and right-click on them, then choose Assign to...
Nodes belonging to different servers need a tunnel between servers to forward data. This is indicated in the GUI with a dashed link line.
The above screenshot shows a gt.42243.61 device added to one of the Linux bridges. This is the GRE tunneling device automatically generated on one of the servers. The gretap device type is used, a gre having a MAC address, so that it may join an Ethernet bridge.

node types and services

Previously the CORE GUI generated router configs for the router node type. This was mostly limited to Quagga OSPFv2 and OSPFv3, without an easy way to customize processes. Now the configuration has been pushed to the CORE services layer (cored.py) and is more exposed to the user.

Node types:
Users may now customize node types. The default types are router, host, PC, and mdr. Clicking the edit button at the end of the submenu allows the user to define new node types or change existing ones.
In the above screenshot, a new node type "supernode" has been defined, and assigned a custom icon. This new node type will appear in the toolbar. Next, a default set of services that will be started with that node type can be selected.
Services: Services can be assigned to a node or node type. When you place a node, it will automatically have the default services configured for that node type. A service can be a routing protocol, server daemon, or even simply a script that runs after the node is started. A service can also auto-generate its config file(s) based on node properties such as name, interfaces, and addresses.

The above screenshot shows the default services that will be started for the custom type "supernode." The below screenshot shows how services can later be customized for each individual node.

Notice the Customize button, available when selecting services for a certain node. This button has been pressed to invoke the custom services dialog. (This dialog may be improved in the future.) Each service defines its own:

• per-node directories
  
• config files
  
• startup index
• startup/shutdown commands

All of the services are defined in Python files (see core/python/core/services/*.py). All of the above attributes may be customized for each node. Future plans are to allow the user to easily define their own service types using Python extensions (probably ~/.core/services/*.py).

Because all of the services are defined in CORE Python daemon, Python scripts (without GUI) will be able to take advantage of auto-generated configs. The bad news is that router configs are no longer saved in the imn scenario files, unless you customize the config files of a service; effectively the imn file format has changed.

custom IP address generator

Configure the next IPv4/IPv6 network that will be assigned.

Configs moved from /etc/core to $HOME/core

A new change in the development version of CORE (svn snapshot) is that the CORE GUI will now use a $HOME/.core directory for configuration that it writes.

• the default scenario dir for imn files is now ~/.core/configs/
• existing ~/.core preferences file is moved to ~/.core/prefs.conf
• plugins.conf, servers.conf, and widgets.conf now live in ~/.core/
• the read-only /etc/core/core.conf file still exists, for configuring the daemon (cored.py)

This fixes bug #25 (http://code.google.com/p/coreemu/issues/detail?id=25)

CORE 4.0 released

A new 4.0 release of CORE is available. To obtain the software, please visit:
http://cs.itd.nrl.navy.mil/work/core/
http://downloads.pf.itd.nrl.navy.mil/core/packages/4.0/

This is the first release of CORE that doesn't require you to patch and recompile your kernel. Using Ubuntu 10.04 or Fedora 12 or 13, you can install a single package (deb or rpm) and build virtual networks, using Linux network namespace containers. FreeBSD 8.x and OpenVZ are still supported platforms.

Quickstart installation instructions are here:
http://code.google.com/p/coreemu/wiki/Quickstart

Quagga is available from the following page with OSPF MDR extensions:
http://cs.itd.nrl.navy.mil/work/ospf-manet/

Standard Quagga may also be used, but the configs generated for wireless routers will not be recognized.

Here are some of the high-level changes since version 3.5:

• Python framework with Linux network namespace (netns) support
• (Linux netns is now the primary supported platform)
• ability to close the GUI and later reconnect to a running session (netns only)
• EMANE integration (netns only)
• new topology generators, host file generator
• user-editable Observer Widgets
• use of /etc/core instead of /usr/local/etc/core
• various bugfixes

disconnected GUI

The notion of Sessions were added to the CORE services, so you can launch a new session using the GUI, exit the GUI while leaving the emulation running, and reconnect at some later time. You can also run multiple sessions simultaneously.



(This only works for Linux network namespaces for now, until FreeBSD and OpenVZ have been ported to using the cored.py Python daemon.)

more images than GIF supported

Use of the Tk::Img library was added to CORE. This allows you to use various image types besides just the GIFs that were supported before -- such as JPG, PNG, TIF, etc. Now the custom node icon and canvas wallpaper dialogs accept various image types.

The Img library is a new dependency for the CORE GUI. You can install it with:

    # for RedHat/Fedora
    yum install tkimg

or

    # for Debian/Ubuntu
    sudo apt-get install libtk-img 

CORE is now a Python package

The CORE Python code has been reorganized into a Python package. New example scripts are included in the source under core/python/examples/netns/. Here is a snippet from one of the samples, how you would make N nodes connected to a switch:

from core import pycore
from core.misc import ipaddr

def main:
    ...
    # IP subnet
    prefix = ipaddr.IPv4Prefix("10.83.0.0/16")
    session = pycore.Session()
    # emulated ethernet switch
    switch = session.addobj(cls = pycore.nodes.SwitchNode)
    print "creating %d nodes with addresses from %s" % \
          (options.numnodes, prefix)
    for i in xrange(1, options.numnodes + 1):
        tmp = session.addobj(cls = pycore.nodes.LxcNode, name = "n%d" % i)
        tmp.newnetif(switch, ["%s/%s" % (prefix.addr(i), prefix.prefixlen)])
        tmp.cmd(["sysctl", "net.ipv4.icmp_echo_ignore_broadcasts=0"])
        n.append(tmp)

    # start a shell on node 1
    n[1].term("bash")

nodes find their place in this world

The Canvas resize dialog was updated to Canvas Size and Scale. This allows you to set a geographic reference point and scale in meters for the canvas, so the traditional X,Y node coordinates can now be translated to lat/long geo coordinates. This support was added so CORE now generates EMANE location events when a node is moved on the canvas.

user-editable Observer Widgets

You can now edit the list of Observer Widgets. Insert your own commands that are run on the node with a mouse over. Changes are saved to a /usr/local/etc/core/widgets.conf file.

grid topology generator

More topology generators were added, the Grid and Connected Grid. Quickly build an NxM wired network with the Connected Grid, or use the Grid to fill the canvas with evenly-spaced disconnected nodes.