Extreme Networks Px Series Operator's manual

Extreme Networks, Inc.
3585 Monroe Street
Santa Clara, California 95051
[phone]
http://www.extremenetworks.com
Px Series
Application Switch
Installation and
Configuration Guide
Published: April 2002
Part number: 100101-00 Rev. 02

II
©2002 Extreme Networks, Inc. All rights reserved. Extreme Networks and BlackDiamond are
registered trademarks of Extreme Networks, Inc. in the United States and certain other jurisdictions.
ExtremeWare, ExtremeWare Vista, ExtremeWorks, ExtremeAssist, ExtremeAssist1, ExtremeAssist2,
PartnerAssist, Extreme Standby Router Protocol, ESRP, SmartTraps, Alpine, Summit, Summit1,
Summit4, Summit4/FX, Summit7i, Summit24, Summit48, Summit Virtual Chassis, SummitLink,
SummitGbX, SummitPx1, SummitRPS and the Extreme Networks logo are trademarks of Extreme
Networks, Inc., which may be registered or pending registration in certain jurisdictions. The Extreme
Turbodrive logo is a service mark of Extreme Networks, which may be registered or pending
registration in certain jurisdictions. Specifications are subject to change without notice.
NetWare and Novell are registered trademarks of Novell, Inc. Merit is a registered trademark of Merit
Network, Inc. Solaris is a trademark of Sun Microsystems, Inc. F5, BIG/ip, and 3DNS are registered
trademarks of F5 Networks, Inc. see/IT is a trademark of F5 Networks, Inc.
All other registered trademarks, trademarks and service marks are property of their respective owners.

Px Series Application Switch Installation and Configuration Guide iii
Contents
Preface
Introduction 1-vii
Conventions 1-viii
Related Publications 1-ix
1 Server Load Balancing Concepts
Purpose of Server Load Balancing 1-1
Terms 1-2
Load Balancing Modes 1-3
Layer 4 Load Balancing 1-3
Layer 7 Load Balancing and Content Analysis 1-4
Port Rewrite 1-6
Getting Started on Load Balancing Configuration 1-6
2 Installing the SummitPx1 Application Switch
Overview of the SummitPx1 Application Switch 2-1
SummitPx1 Front View 2-1
SummitPx1 Application Switch Rear View 2-3
Determining the Location 2-4
Installing the SummitPx1 Application Switch 2-4
Rack Mounting 2-4

iv Px Series Application Switch Installation and Configuration Guide
Free-Standing 2-5
Powering On the SummitPx1 2-5
Setting Up Console Communication 2-6
Configuring Switch IP Parameters 2-7
Configuring the 10/100 Ethernet Management Port 2-8
3 Installing the PxM Application Switch Module
Installing I/O Modules 3-1
Removing I/O Modules 3-2
4 Managing the Switch
Using the Command-Line Interface 4-2
Abbreviated Syntax and Command Completion 4-2
Syntax Symbols 4-2
Line-Editing Keys 4-3
Specifying Text Values 4-3
Command History 4-4
Prompt Text 4-4
Configuring Management Access 4-4
Changing the Default Passwords 4-5
Creating Accounts 4-6
Managing the PxM 4-7
Configuring VLANs 4-8
Configuring SNMP 4-9
Configuring DNS Client Services 4-10
Using Secure Shell 2 (SSH2) 4-11
Enabling SSH2 for Inbound Switch Access 4-12
Using SCP2 from an External SSH2 Client 4-13
SSH2 Client Functions on the Switch 4-14
Utilities 4-15
Showing CPU Load 4-15
Checking Basic Connectivity 4-15
Logging 4-16

Px Series Application Switch Installation and Configuration Guide v
Configuring a Startup Banner Message 4-17
Starting the GlobalPx Content Director Agent 4-17
Example Configuration 4-18
5 Configuring Servers and Services
Configuring Real Servers 5-1
Configuring Server Groups 5-2
Configuring Virtual Services 5-3
Layer 4 Port-based Load Balancing 5-4
Layer 7 Virtual Services 5-4
Configuring Traffic Tagging 5-5
Configuration Example 5-6
6 Choosing Policies, Persistence Modes, and NAT
Scheduling Policies 6-1
Persistence Modes 6-2
UDP Flow Persistence 6-3
Client IP Persistence Mode 6-3
Cookie Persistence Modes 6-5
SSL Session Identifier Persistence 6-13
NAT Modes 6-14
Full-NAT Mode 6-14
Server-only Half-NAT Mode 6-15
Configuration Example 6-17
7 URL Switching
Domain and URL Switching 7-1
Domain Switching 7-2
URL Switching 7-4
Configuring URL Switching 7-4
Creating Domain and URL Switching Rules 7-8
Modifying Existing URL Rules and Domains 7-9

vi Px Series Application Switch Installation and Configuration Guide
Configuration Example 7-9
8 Configuring Redundancy
Using VRRP with the SummitPx1 8-1
Adding and Configuring VRRPs 8-2
Using VRRP in Existing Redundant Networks 8-3
VRRP Automatic Synchronization 8-4
Configuring Redundancy for the PxM 8-6
Using ESRP with the PxM 8-6
Configuring the PxM for Multiple VLANs 8-7
Configuring a Default Gateway 8-8
9 Health Checks
Overview 9-1
Server Startup Pacing 9-2
Health Checking Procedure 9-3
Configuring Health Checks 9-4
Types of Health Checks 9-4
Timers and Counters 9-4
10 Monitoring the Switch
Showing Traffic Statistics 10-1
Showing Configuration Details 10-3
Configuration Displays 10-4
Status Displays 10-5
Managing and Troubleshooting Operation 10-7
Index
Index of Commands

Px Series Application Switch Installation and Configuration Guide vii
Preface
This preface provides an overview of this guide, describes guide conventions, and lists
other publications that may be useful.
Introduction
This guide provides the required information to configure the Extreme Networks Px
series application switches, SummitPx1TM and PxMTM.
This guide is intended for use by network administrators who are responsible for
installing and setting up network equipment. It assumes a basic working knowledge of:
•Local area networks (LANs)
•Ethernet concepts
•Ethernet switching and bridging concepts
•Routing concepts
•Internet Protocol (IP) concepts, including connection initiation process
•Network Address Translation (NAT)
If the information in the release notes shipped with your switch differs from the
information in this guide, follow the release notes.

viii Px Series Application Switch Installation and Configuration Guide
Preface
Conventions
Table 1 and Table 2 list conventions that are used throughout this guide.
Table 1: Notice Icons
Icon Notice Type Alerts you to...
Note Important features or instructions.
Caution Risk of personal injury, system damage, or loss of data.
Warning Risk of severe personal injury.
Table 2: Text Conventions
Convention Description
Screen displays This typeface indicates command syntax, or represents information
as it appears on the screen.
The words “enter”
and “type” When you see the word “enter” in this guide, you must type something, and then press the Return or Enter key. Do not press
the Return or Enter key when an instruction simply says “type.”
[Key] names Key names are written with brackets, such as [Return] or [Esc].
If you must press two or more keys simultaneously, the key names
are linked with a plus sign (+). Example:
Press [Ctrl]+[Alt]+[Del].
Words in italicized type Italics emphasize a point or denote new terms at the place where
they are defined in the text.

Px Series Application Switch Installation and Configuration Guide ix
Related Publications
Related Publications
The publications related to this one are:
•ExtremeWare Software User Guide
•Px Series Application Switch Release Notes
Documentation for Extreme products is available on the World Wide Web at the
following location:
•http://www.extremenetworks.com

xPx Series Application Switch Installation and Configuration Guide
Preface

Px Series Application Switch Installation and Configuration Guide 1-1
1Server Load Balancing Concepts
The Px series application switch marks the next step in server load balancing. Using a
revolutionary hardware design, the Px series application switch is designed to help
website administrators achieve levels of availability and scalability never before
possible.
This chapter contains the following sections:
•Purpose of Server Load Balancing on page 1-1
•Load Balancing Modes on page 1-3
•Port Rewrite on page 1-6
•Getting Started on Load Balancing Configuration on page 1-6
Purpose of Server Load Balancing
An application switch increases website availability by allowing for web servers to fail
(or be shut down for maintenance) without a website outage. It also improves the
response times of the website and increases the traffic-handling capacity of the website
by allowing multiple servers to be used together as a single site.

1-2 Px Series Application Switch Installation and Configuration Guide
The Px series application switch can examine actual user requests, rather than simply
forwarding the requests to the servers. You can use the powerful array of tools provided
by the Px series application switch to scale websites by:
•Creating special purpose servers
•Making better use of web caches
•Allowing movement of web content without extensive re-linking of the site
Terms
The Px series application switch creates a level of abstraction between the real servers
and the Internet, by configuring a virtual IP (VIP) address and port on the application
switch. The VIP has a globally-reachable public IP address, and corresponds to the DNS
entry for the website. All traffic for the website is sent to the application switch, which
applies policies to decide how to forward the traffic to a real server.
Figure 1-1 shows several Internet users all connecting to the website www.busy.com.
Figure 1-1: Conceptual view of server load balancing
WS_012
Real Server 1
10.1.1.3
Virtual Server
www.busy.com
64.10.10.100
Real Server 2
10.1.1.4
Real Server 3
10.1.1.5
235.19.10.1
101.1.35.2
64.64.6.4
193.16.1.36
Internet clients

Px Series Application Switch Installation and Configuration Guide 1-3
Load Balancing Modes
In this document, the Internet users are referred to as clients, because they are clients of
the application switch. The website, which is actually an address inside the application
switch, is also called a virtual IP address, or VIP. Because the Px series application switch
uses the unique combination of IP address and source port, the VIP is referred to as a
virtual service.
Load Balancing Modes
The Px series application switch can perform packet redirection for load balancing in
two different ways:
•Layer 4 load balancing
•Layer 7 load balancing
Layer 4 Load Balancing
In layer 4 mode, the application switch decides which server should receive a given
user request using server selection policies. It selects a server without looking at the
content of the request. The following server selection policies are supported by the Px
series application switch:
•Round robin
•Weighted round robin
•Least connections
•Weighted least connections
For more information on policies, see Chapter 6.
The application switch can balance almost any traffic using network address translation
(NAT) at layer 4. The application switch rewrites the destination IP address of the
request to point to the real server selected to handle the request, and sets the source IP
address of the request to point to one of the internal IP addresses of the Px series
application switch. When the server responds to the request, the application switch
rewrites the response so that it appears to originate from its VIP address, and forwards
the response to the client.
Figure 1-2 illustrates a single client-server transaction using layer 4.

1-4 Px Series Application Switch Installation and Configuration Guide
Figure 1-2: Single client-server transaction using layer 4
As soon as the first request from the client is received at the application switch, the
application switch uses the server-selection policy configured for the VIP to select the
server and immediately sends out the NAT-ed request to the real server. The client and
server continue the connection establishment protocol using the application switch in
the middle, NAT-ing the traffic. After the connection is established, an HTTP request is
sent and the server responds.
Layer 7 Load Balancing and Content Analysis
To make server-selection decisions based on cookies or the URL being requested by the
client, the application switch must actually look inside the client request. Because this
data request is only sent out after a connection is established, the Px series application
switch must first act as a proxy for the server by acting as the endpoint of the TCP/IP
connection from the client. This process is called layer 7 load balancing.
The Px series application switch delays the establishment of a connection to a server
until the first 1500 bytes of actual data (the HTTP request) is received from the client.
The application switch then takes the content being requested, along with the domain to
which the request pertains, and applies policy rules. Based on the outcome of the policy
decision, the application switch establishes a TCP connection with the real server
WS_013
Client Real Server
SYN
SYN/ACK
ACK
DATA
(http request)
1

Px Series Application Switch Installation and Configuration Guide 1-5
Load Balancing Modes
chosen to process the request, using a source IP address that is part of a proxy pool
inside the application switch.
After a connection is established between the application switch and the real server, the
application switch forwards the buffered data to the server. The server sends any
response to the application switch. The application switch translates the IP source
address and port numbers appropriately, along with the TCP sequence and
acknowledgment numbers, and then forwards the data to the real client on the Internet.
Return traffic from the real server does not require content analysis, and is simply
rewritten by the NAT engine.
Figure 3 illustrates the sequence used to establish a layer 7 request.
Figure 1-3: Establishing a layer 7 request

1-6 Px Series Application Switch Installation and Configuration Guide
Port Rewrite
When a request is sent by a client to a VIP service, the request contains the well-known
port number for the requested application. For example, the well-known port number
for HTTP is port 80.
You can configure the application switch to rewrite the port, configuring a server group
to use a specific port, other than the well-known port number for the application. Port
rewrite is useful in instances where multiple domains are configured on the same server
(or all servers in the same server group) and each domain has its own server process.
By giving each domain its own port number, each server process can be configured to
listen for requests at its own port.
Getting Started on Load Balancing Configuration
To successfully configure the Px series application switch to perform load balancing
operations, you must consider the following:
•Do you want to use full NAT or server-only NAT mode? For more information on
NAT, see Chapter 6.
•Do you want to use IP address history? For more information on IP address history,
see Chapter 6.
•What server selection policies do you want to use? For more information on
selection policies, see Chapter 6.
•If URL switching is going to be implemented, what DNS domains and patterns will
be used? For more information on URL switching, see Chapter 7.
•If cookies will be used, what cookie mode will be selected, and are the cookies
configured properly on the web servers? For more information on cookies, see
Chapter 6.
After these decisions have been made, follow these steps to configure load balancing:
1Configure the system IP and related information. For more information, see
Chapter 4.
2Configure the appropriate global parameters such as NAT mode, proxy-IPs, and
stickiness options. For more information, see Chapter 6.
3Configure the servers and virtual services:

Px Series Application Switch Installation and Configuration Guide 1-7
Getting Started on Load Balancing Configuration
aConfigure the real servers that will be load balanced.
bCreate groups of servers, and put the real servers into them.
cCreate a virtual service.
—If the virtual service is layer 4, assign a server group to it.
—If the virtual service is layer 7, create the appropriate domains and pattern-rules,
and assign server groups to the pattern-rules.
For more information, see Chapter 5.

1-8 Px Series Application Switch Installation and Configuration Guide

Px Series Application Switch Installation and Configuration Guide 2-1
2Installing the SummitPx1
Application Switch
This chapter describes how to install the SummitPx1 configuration of the Px series
application switch. It contains the following sections:
•Overview of the SummitPx1 Application Switch on page 2-1
•Determining the Location on page 2-4
•Installing the SummitPx1 Application Switch on page 2-4
•Setting Up Console Communication on page 2-6
•Powering On the SummitPx1 on page2-5
Overview of the SummitPx1 Application Switch
SummitPx1 Front View
Figure 2-1 shows the Px series application switch front view.
Figure 2-1: SummitPx1 application switch front view
SPx1_front
Unit status
LEDs Network Interface port Ethernet Management
LEDs and port
Serial
Management
ports

2-2 Px Series Application Switch Installation and Configuration Guide
Table 2-1 describes the LED behavior on the SummitPx1.
The front panel of the SummitPx1 has four ports:
•Gigabit Interface Connector (GBIC)
The Network Interface port is a Gigabit Interface Connector (GBIC) used to connect
the application switch to your local network.
•100BASE-Tx Ethernet Management (RJ-45)
The Ethernet Management port (RJ-45 connector) is a 10/100 Mbps Ethernet
connection used for out-of-band management.
•Console (serial RJ-45)
The console port (serial RJ-45 connector) is used to connect a terminal for local
out-of-band management. The console operates at 9600 baud, 8 data bits, no parity,
one stop bit (8-N-1) with no hardware flow control.
Use the included DB-9 adapter to connect the console to a PC serial port, using a
straight (1-8, 1-8) cable, such as a standard category 3 or category 5 Ethernet cable.
The pinouts for the DB-9 adapter are shown in Table 2-2 on page 2-3.
If you are wiring the console port to a console server, you must use a null modem
cable (1-8, 8-1).
•AUX (serial RJ-45)
The AUX port (RJ-45 connector) has the same pin-outs as the console port. The AUX
port is used for remote out-of-band management.
Table 2-1: Px series application switch LEDs
LED Color Indicates
Link Green
Yellow flashing
The 1000Base-T link is operational.
There is activity on this link.
Management Green flashing
■Slow
■Fast
Red
The Px series application switch is operating normally.
Power On Self Test (POST) in progress.
The Px series application switch has failed its POST.
Power Green
Red
The Px series application switch is powered up.
The Px series application switch is indicating a power or
temperature problem.