Alteon Application Switch Operating System Application Guide
Content-Intelligent Server Load Balancing Not Using Layer 7 Content Switching Rules
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Document
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RDWR-ALOS-V2900_AG1302
The GET request does not include the hostname. From the TCP/IP headers, the origin server
knows the requests hostname, port number, and protocol.
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With the extension to HTTP/1.1 to include the HTTP HOST: header, the above request to retrieve
the URL www.radware.com/products/Alteon would look like this:
GET /products/Alteon/ HTTP/1.1
Host: www.radware.com
User-agent: Mozilla/3.0
Accept: text/html, image/gif, image/jpeg
The Host: header carries the hostname used to generate the IP address of the site.
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Based on the Host: header, Alteon forwards the request to servers representing different
customer Web sites.
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The network administrator needs to define a domain name as part of the 128 supported URL
strings.
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Alteon performs string matching. That is, the string "radware.com" or "http://
www.radware.com/” " matches ""http://www.radware.com/".
Virtual Hosting Configuration Overview
The following is the sequence of events for configuring virtual hosting based on HTTP Host: headers:
1. The network administrator defines a domain name as part of the 128 supported URL strings.
Both domain names "www.company-a.com" and "www.company-b.com" resolve to the same IP
address. In this example, the IP address is for a virtual server on Alteon.
2. "www.company-a.com" and "www.company-b.com" are defined as URL strings.
3. Server Group 1 is configured with Servers 1 through 8.
Servers 1 through 4 belong to "www.company-a.com" and Servers 5 through 8 belong to
"www.company-b.com."
4. The network administrator assigns string "www.company-a.com" to Servers 1 through 4 and
string "www.company-b.com" to Servers 5 through 8.
5. Alteon inspects the HTTP host header in requests received from the client.
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If the host header is "www.company-a.com," Alteon directs requests to one of the Servers 1
through 4.
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If the host header is "www.company-b.com," Alteon directs requests to one of the Servers 5
through 8.
Configuring the Host Header for Virtual Hosting
To support virtual hosting, configure Alteon for Host header-based load balancing
1. Before you can configure host header-based SLB, ensure that Alteon has already been
configured for basic SLB:
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Assign an IP address to each of the real servers in the server pool.
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Define an IP interface.
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Define each real server.
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Assign servers to real server groups.
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Define virtual servers and services.
For information on how to configure your network for SLB, see