Alloy NS-16T User Manual download pdf

CAIA Technical Report 031217A December 2003 page 1 of 15

Testing the Alloy NS-16J Switch Using Tcpdump

Centre for Advanced Internet Architectures.

Technical Report 031217A

Swinburne University of Technology

Melbourne, Australia

Ana M. Pavlicic, Grenville Armitage

apavlicic@swin.edu.au, garmitag[email protected]

Abstract - This technical report investigates how the

Alloy NS-16J 16-port switch handles packets arriving on

its backplane using three different methods of starting

packet bursts. The packet bursts are generated by Netcom

SmartBits2000 using Netcom SmartWindow software. The

switch will be used in future research as part of the

MAGIC project.

Keywords - switch, CAM, MAC address, packet, tcpdump, port

NTRODUCTION

This report investigates the performance of the Alloy

NS-16J 10/100Mbps switch using a Netcom Systems

SmartBits2000 device to generate test traffic. The

SmartBits2000 is configured with four SX-7410B

100Mbps Ethernet cards connected via CAT5 UTP cable

to the switch. The Smartbits2000 was used to generate

UDP packet streams using the Windows-based

SmartWindow software provided. SmartWindow

enables the user to send packets from one card to another

specific card(s) or to simply flood all card ports with

packets.

SmartWindow was used to estimate the actual CAM

table size and flood tcpdump with packets from the

switch to look at packet burst patterns. The process was

then repeated with a hub and a high performance Cisco

switch for comparison.

II. TEST SET UP

A. Physical connections between devices used in the

investigation and SmartWindow.

For the CAM table tests each of the four cards were

connected via CAT5 UTP to one port on the 16-port

Alloy switch. In the tcpdump test, another UTP cable

was connected to one of the switch/hub ports at one end

and to a separate PC running tcpdump on the other. This

set up can be seen in Figure 1.

With SmartWindow the user is able to set various test

characteristics such as the link utilisation level, the total

number of packets sent, the size of the packet payload,

the number of different MAC addresses in the system,

the protocol used etc.

III.CAM TABLE SIZE

A. Investigating the CAM table size to determine whether the

manufacturer’s quoted size holds true.

The manufacturer quoted the size of the NS-16J

CAM to have room for “8k” MAC addresses [1]. The

purpose of this test was to investigate the actual size of

the CAM table to know its capability in handling a large

number of differing MAC addresses.

B. Can the CAM table hold 8,000 MAC address and port

entries?

The first step to finding the size of the CAM table

was to fill the CAM with 8,000 MAC addresses using

card 2. The utilisation was set to 1% on each card and

packet payload size to 64 bytes. Card 1 was then used to

cycle through the 8,000 MAC addresses as the

destination of the packets it sent. 100,000 packets were

sent. This test was repeated with the number of MAC

addresses increased after every trial. It was found that

flooding first occurred when 8,321 varying MAC

addresses were sent by card 2 to the CAM table. This

would suggest that the CAM was full at 8,320 MAC

entries and did not record the 8,321

MAC address. This

simple test determined the CAM to have enough room

for 8,320 MAC addresses and their corresponding port

entries. There were no packets lost during this test.

C. Validating the size of the CAM table.

This time card 3 was used to fill the MAC table with

8,000 MAC addresses and then cards 1 and 2 cycled

though 4,000 MAC addresses, each sending 100,000

packets to card 3. The switch registered that the port

Figure 1 : Test Set up showing Tcpdump connection

Ethernet

Card

PC Running

SmartWindow and

SmartApplications

PC Running

Tcpdump

SmartBits2000

Switch

Port

Packets Flooded

Packet

Flow

Alloy

Switch

(not all

ports

shown)

1 2 3 4

PC Running

SmartWindow

1 2 3 4 5

Summary of Contents

Page 1 - SmartWindow

CAIA Technical Report 031217A December 2003 page 1 of 15 Testing the Alloy NS-16J Switch Using Tcpdump Centre for Advanced Internet Architectures.

Page 2

CAIA Technical Report 031217A December 2003 Page 2 of 5 card 3 was connected to as the source of all the MAC addresses, thus packets would then b

Page 3

CAIA Technical Report 031217A December 2003 Page 3 of 5 Figure 2: Cumulative packets vs time all start options (first 32,000 packets)

Page 4 - V. CONCLUSION

CAIA Technical Report 031217A December 2003 Page 4 of 5 F. Investigating the number of packets tcpdump would record when the Alloy switch is repla

Page 5 - REFERENCES

CAIA Technical Report 031217A December 2003 Page 5 of 5 ACKNOWLEDGMENTS Dr. Paul van den Bergen from the Centre for Advanced Internet Ar

Alloy NS-16T User Manual

Browse online or download User Manual for Network switches Alloy NS-16T. Testing the Alloy NS-16J Switch Using Tcpdump - CAIA

Summary of Contents

More documents for Network switches Alloy NS-16T

Comments to this Manuals

Alloy NS-16T User Manual

Browse online or download User Manual for Network switches Alloy NS-16T. Testing the Alloy NS-16J Switch Using Tcpdump - CAIA

Summary of Contents

More documents for Network switches Alloy NS-16T

Comments to this Manuals

Related products and manuals for Network switches Alloy NS-16T