Configuring Direct Server Return (DSR)
Equalizer Installation and Administration Guide
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lo:dsr Link encap:Local Loopback
inet addr:
cluster-ip
Mask:255.255.255.255
UP LOOPBACK RUNNING MTU:16436 Metric:1
3. To configure an Apache 2.0 server for DSR, edit the server configuration file to add a
Listen
directive for the
cluster IP (on many systems, the configuration file is found at
/usr/local/etc/apache/httpd.conf
). Look for the
first line beginning with the Listen directive, and add another line that looks like this:
Listen
cluster-ip
Where
cluster-ip
is the DSR-enabled cluster IP. Save your changes to the file.
4. Reboot the Apache server:
# apachectl restart
You should now be able to send client requests to the cluster IP and port, and get responses directly from the Apache
server running on Linux. Remember that static routes on your servers may be necessary, depending on your network
configuration.
Configuring a Loopback Interface on Other Systems for DSR
The commands and interfaces used to configure a loopback interface vary slightly between operating systems, and
sometimes between versions of the same operating system. Check the documentation for your server operating
system for instructions on how to configure a loopback interface. For example, on some BSD systems, the command
used in Step 1 in the previous section would be slightly different, as shown below:
# ifconfig lo0
cluster-ip
netmask
cluster-netmask
alias
Notice that in this case, the netmask used matches the netmask used to configure the cluster on Equalizer, instead of
255.255.255.255 as in the Linux system example.
Weak and Strong Host Models and DSR
Network interfaces on non-routing systems use either the “weak host” or “strong host” models for packet
transmission and reception (these models are defined in RFC1122). In the “strong host” model, a system that is not
acting as a router cannot send or receive any packets on a given interface unless the destination/source IP in the
packet is assigned to the interface. In the “weak host” model, this restriction does not apply.
In order for DSR to work, the “weak host” model must be enabled on the server’s loopback interface, as well as the
interface on which requests are received from Equalizer.
Most Linux and Unix systems default to the “weak host” model on all network interfaces, so no additional
configuration is usually necessary. For example, on FreeBSD and NetBSD, this behavior is controlled by the setting
of
sysctl net.inet.ip.check_interface
, which by default is set to 0 (“weak host”).
Windows XP and Windows 2003 use the “weak host” model on all IPv4 interfaces and the “strong host” model on
all IPv6 interfaces, and this is not configurable.
Windows Vista and Windows 2008 support “strong host” by default on all interfaces, but this is configurable for
individual interfaces. Use the following command to list interface status:
netsh interface [ ipv4 | ipv6 ] show interface
The following three command are an example of changing the mode to “weak host” for the LAN and loopback
interfaces:
netsh interface ipv4 set interface "Local Area Connection" weakhostreceive=enabled
netsh interface ipv4 set interface "Loopback" weakhostreceive=enabled
netsh interface ipv4 set interface "Loopback" weakhostsend=enabled
The interface names used in quotes above must match the interface names that appear in the Windows
Network
Connections
folder.
Содержание E350GX
Страница 18: ...Chapter Preface 18 Equalizer Installation and Administration Guide ...
Страница 38: ...Chapter 1 Equalizer Overview 38 Equalizer Installation and Administration Guide ...
Страница 50: ...Chapter 2 Installing and Configuring Equalizer Hardware 50 Equalizer Installation and Administration Guide ...
Страница 62: ...Chapter 3 Using the Administration Interface 62 Equalizer Installation and Administration Guide ...
Страница 80: ...Chapter 4 Equalizer Network Configuration 80 Equalizer Installation and Administration Guide ...
Страница 110: ...Chapter 5 Configuring Equalizer Operation 110 Equalizer Installation and Administration Guide ...
Страница 208: ...Chapter 7 Monitoring Equalizer Operation 208 Equalizer Installation and Administration Guide ...
Страница 240: ...Chapter 8 Using Match Rules 238 Equalizer Installation and Administration Guide ...
Страница 258: ...Chapter 9 Administering GeoClusters 254 Equalizer Installation and Administration Guide Envoy Configuration Worksheet ...
Страница 262: ...Appendix A Server Agent Probes 258 Equalizer Installation and Administration Guide ...
Страница 274: ...Appendix B Timeout Configuration 270 Equalizer Installation and Administration Guide ...
Страница 280: ...Appendix D Regular Expression Format 276 Equalizer Installation and Administration Guide ...
Страница 296: ...Appendix E Using Certificates in HTTPS Clusters 292 Equalizer Installation and Administration Guide ...
Страница 310: ...Appendix F Equalizer VLB 306 Equalizer Installation and Administration Guide ...
Страница 318: ...Appendix G Troubleshooting 314 Equalizer Installation and Administration Guide ...