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Cisco CSS 11000 Series Content Services Switches

Virtual Web Hosting Application Guide

Document ID: 3835

Updated: Jan 31, 2006

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Introduction

Due to the number of ISPs that provide web hosting services to their customers, there is a need to support hundreds to thousands of virtual web sites on relatively few web servers. Virtual Web Hosting Applications extend past the ISP and into the market place. Some Web Vendors use Domain Names as search engines or to categorize the streaming media.

The basic concept is that the web-hoster has a few machines, typically from two to ten, that mirror the content. Each machine has hundreds to thousands of sites on it. The servers determine which site is requested based on the IP address, port, or Domain Name. When you try to load balance such a site, the load balancer must be able to configure with many services and virtual IP addresses or Domain Names.

Cisco has developed a solution for the need to provide this type of service. The Virtual Web Hosting Software allows the web hoster to configure a service with either a range of IP addresses or a range of ports. A content rule with either a range of VIPs or a list of Domain Names is configured to map to the servers. A content rule with a range or a list can map to a server without a range. This allows a many-to-one mapping.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document is not restricted to specific software and hardware versions.

Conventions

For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Configuration

When you configure the VIP and service ranges, Cisco recommends that you stay within the subnet that you use. The CSS does not arp for IP addresses that are not on the subnet of the circuit.

For example, if you configure the circuit for 10.10.10.1/24 and configure the VIP range as 10.10.10.2 range 400, the CSS does not arp for any of the addresses beyond 10.10.10.254.

However, if you configure the circuit for 10.10.10.1/24 and configure the VIP range as 10.10.10.2 range 200, the CSS does arp for all addresses in the range.

For large VIP ranges, Cisco recommends that you have the upstream router advertise a route through the CSS to the VIP subnets in order to prevent arp storms and excessive failover times with redundancy.

This diagram provides an example:

v_webhost_app_3835.gif

Configure the CSS with four content rules, one for each VIP range, and four services for each server in order to prevent issues with network numbers and subnet broadcast numbers (0 and 255).

In order to prevent issues with arp storms, it is best to configure the upstream router to route all of the VIP addresses to the CSS. If you configure the VIP ranges on the same subnet as the circuit, the CSS does arp for them. Also, when you have a large number of VIPs, it takes a long period of time for redundancy to take effect.

The CSS can be configured to advertise the routes to the VIPs.

Note: You can only configure local services with ranges and add to content rules with ranges.

  1. Configure the service.

    config
    
    service web1
    
    ip address 10.0.0.1 range 50
    
    or
    
    port 40000 range 50
    
    (the range can be from 2 to 65535)
    
    protocol tcp
    
    keepalive type http
    
    keepalive method get
    
    keepalive uri "/index.html"
    
    (the keepalive will be sent to the first IP or port in the range)
    
    active
  2. Configure the rule with the use of a VIP range.

    config
    
    owner virtual_sites
    
    content virtual_rule
    
    vip address 200.200.200.1 range 50
    
    port 80
    
    protocol tcp
    
    add service web1
    
    add service web2
    
    active
  3. Configure DQLs.

    Note:  Cisco does not recommend the configuration of more than 1,000 domain names.

    config
    
    dql my_domains
    
    domain www.customer1.com index 1 description "aaa company"
    
    domain www.customer2.com index 2
    
    domain www.customer3.com index 3
    
    domain www.customer4.com index 4
    
    domain www.customer5.com index 5
    
    domain www.customer6.com index 6
    
    domain www.customer7.com index 7
    
    domain www.customer8.com index 8
    
    domain www.customer9.com index 9
    
    domain www.customer10.com index 10
    
    domain www.customer11.com index 11
    
    domain www.customer12.com index 12
    
    domain www.customer13.com index 13
    
    domain www.customer14.com index 14
    
    domain www.customer15.com index 15
    
    domain www.customer16.com index 16
    
    domain www.customer17.com index 17
    
    domain www.customer18.com index 18
    
    domain www.customer19.com index 19
    
    domain www.customer20.com index 20
    
    domain www.customer21.com index 21
    
    domain www.customer22.com index 22
    
    domain www.customer23.com index 23
    
    domain www.customer24.com index 24
    
    domain www.customer25.com index 25
    
    domain www.customer26.com index 26
    
    domain www.customer27.com index 27
    
    domain www.customer28.com index 28
    
    domain www.customer29.com index 29
    
    domain www.customer30.com index 30
    
    domain www.customer31.com index 31
    
    domain www.customer32.com index 32
    
    domain www.customer33.com index 33
    
    domain www.customer34.com index 34
    
    domain www.customer35.com index 35
    
    domain www.customer36.com index 36
    
    domain www.customer37.com index 37
    
    domain www.customer38.com index 38
    
    domain www.customer39.com index 39
    
    domain www.customer40.com index 40
    
    domain www.customer41.com index 41
    
    domain www.customer42.com index 42
    
    domain www.customer43.com index 43
    
    domain www.customer44.com index 44
    
    domain www.customer45.com index 45
    
    domain www.customer46.com index 46
    
    domain www.customer47.com index 47
    
    domain www.customer48.com index 48
    
    domain www.customer49.com index 49
    
    domain www.customer50.com index 50
  4. Configure a rule with the use of the DQL.

    config
    
    owner virtual_sites
    
    content virtual_rule
    
    dql my_domains
    
    vip address 200.200.200.200
    
    port 80
    
    protocol tcp
    
    add service web1
    
    add service web2
    
    active

Related Information

Updated: Jan 31, 2006
Document ID: 3835