Configuring A Loopback Interface On Other Systems For Dsr; Weak And Strong Host Models And Dsr - Coyote Point Systems E350GX Installation And Administration Manual

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
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
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
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
folder.
Connections
Equalizer Installation and Administration Guide
is the DSR-enabled cluster IP. Save your changes to the file.
, which by default is set to 0 ("weak host").
Configuring Direct Server Return (DSR)
directive for the
Listen
Network
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