Passing information to HTTP backend servers in IPv4-IPv6 mixed-mode load balancing

Passing information to HTTP backend servers in IPv4-IPv6 mixed-mode load balancing -

Consider this scenario - you expose your web services to customers using IPv6 IPv6 VIP (Virtual IP) on NetScaler. In the backend servers are IPv4 and IPv6 hosts mixture serving the same content to end users. NetScaler allows you to link combination of IPv6 and IPv4 servers to the same virtual server. When demand reaches NetScaler, he decided to use one of IPv4 or IPv6 servers related to it based on the load balancing algorithm selected

For the purposes of this blog, the following configuration was used :.

• VIP (IPv6) - 02 :: 11
• IPv4 Server - 10.102.216.6
• IPv6 Server - 02 :: 6
• IPv4 SNIP - 10.102 .216.15
• IPv6 SNIP - 02 :: 15

for such a scenario works correctly, ensure that the IP information transported by an HTTP header is aligned with the type of server demand will. If the request goes to IPv4 servers, HTTP headers must carry IPv4 addresses and ditto for IPv6 servers. If an IPv4 server obtains an IPv6 address in a header where it awaits the IPv4 address, the server rejects the request.

NetScaler provides the mechanism to change existing "host" header in HTTP packets or insert new headers with IP information. There are two methods:

1. IP6 set ns -map

With this command you can create a mapping between the IPv6 address and IPv4 address. Whenever the NetScaler load balancing application server to IPv6, IPv6 information in the host header is retained. But whenever the NetScaler load balancing application server in IPv4, mapped IP is inserted into the Host header. This ensures that the IPv4 server processes the request without error

Example :. Set ns ip6 02 :: 11 -map 10.10.10.11

When the request is load balanced server to IPv6:

When the request is load balanced to the IPv4 server:

2. set lb vserver [-insertVserverIPPort []]

insertVserverIPPort three possible values ​​- OFF, and VIPADDR V6TOV4MAPPING. The default is OFF.

When VIPADDR is used, NetScaler inserts the VIP IPv6 with the new "vipHeader"
When V6TOV4MAPPING, NetScaler inserts IPv6 VIP for queries to IPv6 and mapped IPv4 IP servers for requests to IPv4 servers with the new "vipHeader

:. Set Example lb vserver VS6 -insertVserverIPPort V6TOV4MAPPING" vip-header64 "

This will add the" vip-header64 "for HTTP packets

.

Where the application is load balanced on the IPv4 server:

When the request is load balanced on the IPv6 server:

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