NIST Net WAN Emulation Software Installation and Configuration Note

Transcription

1 NIST Net WAN Emulation Software Installation and Configuration Note This document describes the steps needed to successfully install and configure NIST Net using the NIST Net distribution CD-ROM provided by Cisco Systems. NIST Net is a network emulation package that runs on Linux. The NIST Net network emulator is a general-purpose tool for emulating performance dynamics in IP networks. The tool is designed to allow controlled, reproducible experiments with network performance-sensitive/adaptive applications and control protocols in a simple laboratory setting. By operating at the IP level, NIST Net can emulate the critical end-to-end performance characteristics imposed by various wide area network situations (e.g., congestion loss) or by various underlying subnet technologies (e.g., asymmetric bandwidth situations of xdsl and cable modems). NIST Net by default is used to add latency, bandwidth limitations, packet loss or duplication, and other WAN characteristics on all IP traffic moving between the Ethernet ports of the system, while exclusions to this directive can be added on a per system basis. For more information about NIST Net, visit the NIST Net website at: Figure 1 NIST Net Typical Setup Data Center Branch office Solaris Saturn Windows DC /24 WAN Emulator /24 Novell NWUS01 Windows Neptune Edge FE Edge FE HPLJ ETH0: ETH1: Corporate Headquarters: Cisco Systems, Inc., 170 West Tasman Drive, San Jose, CA USA Copyright 2005 Cisco Systems, Inc. All rights reserved.

2 Hardware Requirements Hardware Requirements The following is the minimal hardware configuration required for a successful installation, configuration, and execution of NIST Net. 10 GB hard drive 256 MB RAM 2 network interface cards (NICs) Note The distribution is based on Red Hat Linux, thus hardware used for this installation needs to be compatible with Red Hat Enterprise Linux 3.0 or higher. Software Installation To install the NIST Net software on a LINUX workstation, follow these steps: Step 3 Insert the Cisco-provided disc in the CD-ROM drive and boot up the workstation. Press Enter at the installation screen to select the minimal Cisco NIST Net installation option. Wait for the Nist Net installation to complete. When the installation finishes, the installation disc ejects and the system reboots. 2

3 System Configuration System Configuration Once the system has rebooted, log on using the root user (password is "default") and configure the system's hostname, default gateway, and network interface cards. You do this by editing the files using vi, and then restarting the system as described in the following steps: Configure the hostname and default gateway. Enter the command: vi /etc/sysconfig/network Set these values: NETWORKING=yes HOSTNAME=emulator GATEWAY= Save the file and exit by pressing ESC, Shift-;, typing wq at the colon prompt(:), and pressing the Enter key. Configure the ETH0 and ETH1 devices. Enter the command: vi /etc/sysconfig/network-scripts/ifcfg-eth0 Set these values: DEVICE=eth0 BOOTPROTO=static ONBOOT=yes IPADDR= NETMASK= BROADCAST= Save the file and exit by pressing ESC, Shift-;, typing wq at the colon prompt(:), and pressing the Enter key. Edit the file: vi /etc/sysconfig/network-scripts/ifcfg-eth1 Set these values: DEVICE=eth1 BOOTPROTO=static ONBOOT=yes IPADDR= NETMASK= BROADCAST= Save the file and exit by pressing ESC, Shift-;, typing wq at the colon prompt(:), and pressing the Enter key. Step 3 Restart network services using the following command: service network restart 3

4 Launching NIST Net Adding a Persistent Static Route to NIST NET To add a persistent route to NIST NET, follow these steps: Step 3 Step 4 Step 5 Go to /etc/sysconfig/network-scripts. Make a file called route-devicename (for example, route-eth0). Populate this file with your static routes for the device. For example, if you want to make a static route to the /24 network through , you would type: /24 via Reload the box. Log in as root/default and type route. You should see your new persistent static route. Launching NIST Net To launch NIST Net, follow these steps: From the /root directory, enter the command:./nistnet If this is the first time you launch NIST Net, the package will build itself based on the hardware configuration. Once completed, you see a menu from which you can launch the emulation tool with different network settings. Please select a preset from the following options: : 40ms round-trip delay, T1 bandwidth, 0.5% packet loss 2: 60ms round-trip delay, T1 bandwidth, 0.5% packet loss 3: 80ms round-trip delay, T1 bandwidth, 0.5% packet loss 4: 100ms round-trip delay, T1 bandwidth, 0.5% packet loss 5: 120ms round-trip delay, T1 bandwidth, 0.5% packet loss 6: 160ms round-trip delay, T1 bandwidth, 0.5% packet loss 7: Custom Settings 8: Stop WAN Emulation 9: Exit Using the menu, you can set up the network environment with preconfigured values (1-6) or your own custom settings (7). To stop emulation altogether, use menu option 8. For examples, refer to the Using NIST Net section on page 5. 4

5 Using NIST Net Using NIST Net This section contains examples of how to use NIST Net. Example 1 To set the network for 80ms round trip latency, with a T1 (1,544 Kbps) and 1/2%packet loss - select option 3 from the NIST Net menu. If the activation is successful, you see this screen. 3 * NISTnet Activation Script * Clearing WAN table and loading NISTnet... Configuring NISTnet... Reading WAN table: cnistnet -a delay drop bandwidth drd Done. Activation of the script clears the current WAN table (line 1), configures NIST Net to the desired settings (line 2), and lastly displays the current WAN table (line 3). The current table consists of one entry - any IP to any IP going through NIST Net will be subjected to a 40 ms latency (a total of 80 ms round trip), ½% packet loss and limited to a T1 bandwidth. In this example, the bandwidth value of bytes is derived from the following formula: T1 = (1,544 Kbits/sec) * 1024 = ( bits/sec)/8 = bytes/sec. Example 2 If you want custom settings, select option 7 on the NIST Net menu. You are prompted to enter your settings, as shown in the example below. 7 Custom WAN Settings: Enter bandwidth [bytes]: Enter one-way delay [millisec]: 25 Enter packet-loss [percent]:.25 * NISTnet Activation Script * Clearing WAN table and loading NISTnet... Configuring NISTnet... Reading WAN table: cnistnet -a delay drop bandwidth drd Done. You are prompted to specify the bandwidth in bytes (line 1), a one-way latency in milliseconds (line 2) and the percent packet loss (line 3). Remember to press the Enter key after entering each value. In this example, NIST Net is set up to provide a 768 Kbps (½T1) line with a total of 50 ms round trip latency and ¼% packet loss. In this example, the bandwidth value of bytes is derived from the following formula: T1 = (1,544 Kbits/sec) * 1024 = ( bits/sec)/8 = ( bytes/sec)/2. 5

6 & Server Configuration & Server Configuration In order for the WAN emulation tool to affect client and server network traffic (i.e., add latency, bandwidth limitation, etc.) at the emulated WAN edges, NIST Net should be treated as the router for both sides of the WAN. On each participating client or server, configure the default gateway to point to the relevant IP address of the NIST Net system. This concludes the NIST Net WAN Emulation Tool installation and configuration. For more information, refer to the NIST Net website at Note NIST Net is available online at and is included in this distribution package for your convenience. Questions about NIST Net should be directed to The software is provided as-is for use at your own risk. Cisco Systems, Inc makes no warranty of any kind, either expressed or implied, as to the results that may be obtained from the use of NIST Net, or as to the accuracy, reliability, or content of any information or service contained in or provided through the software. CCSP, CCVP, the Cisco Square Bridge logo, Follow Me Browsing, and StackWise are trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, and iquick Study are service marks of Cisco Systems, Inc.; and Access Registrar, Aironet, ASIST, BPX, Catalyst, CCDA, CCDP, CCIE, CCIP, CCNA, CCNP, Cisco, the Cisco Certified Internetwork Expert logo, Cisco IOS, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Cisco Unity, Empowering the Internet Generation, Enterprise/Solver, EtherChannel, EtherFast, EtherSwitch, Fast Step, FormShare, GigaDrive, GigaStack, HomeLink, Internet Quotient, IOS, IP/TV, iq Expertise, the iq logo, iq Net Readiness Scorecard, LightStream, Linksys, MeetingPlace, MGX, the Networkers logo, Networking Academy, Network Registrar, Packet, PIX, Post-Routing, Pre-Routing, ProConnect, RateMUX, ScriptShare, SlideCast, SMARTnet, StrataView Plus, TeleRouter, The Fastest Way to Increase Your Internet Quotient, and TransPath are registered trademarks of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries. All other trademarks mentioned in this document or Website are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0502R) Copyright 2005 Cisco Systems, Inc. All rights reserved. Printed in the USA on recycled paper containing 10% postconsumer waste. 6