WAN Emulator

Overview

The WAN Emulator node type is used for performing link conditioning within a lab.

Features

The refplat ISO includes a WAN Emulator image that provides the ability to emulate WAN characteristics. The following characteristics are supported:

packet loss percentage
packet latency, including a configurable amount of jitter in the delay
throughput limit

The image also includes the same network troubleshooting tools that are available on Alpine nodes:

iperf -- basic traffic generation
routem -- OSPF/BGP control plane traffic generation
tcpdump -- packet capture
traceroute
ping
telnet
ssh

Limitations

WAN Emulator nodes have just two interfaces.

Using WAN Emulator Nodes in CML

You can think of the WAN Emulator node as sitting inline on a connection, but you really build the lab by connecting two other nodes to the WAN Emulator node. The WAN Emulator takes all of the traffic that it receives on one interface, applies the configured link conditioning, and then sends the resulting packets out on the other interface.

The Wan Emulator VM image on the refplat ISO has a locked root account. An initial user account will be created when the VM boots. By default, a cisco account with password cisco is created. You can override the username and password for this initial user account by setting the USERNAME and/or PASSWORD in the Edit Config pane for the node in the Workbench.

You can create a static configuration for the link conditioning parameters. Simply provide values for these configuration parameters in the node's Edit Config pane in the Workbench:

Configuration example:

# this is a shell script which will be sourced at boot
hostname wan-em-0
# configurable user account
USERNAME=cisco
PASSWORD=cisco
# WAN Emulator configuration
LATENCY="100"
JITTER="0"
LOSS="0.0"
BANDWIDTH="512"

You may also set these configuration parameters at runtime. The image runs a text-based UI, which allows you to configure and monitor the WAN Emulator via the node's console while the lab is running.