Extreme Networks Px Series - Page 66

6-8 Px Series Application Switch Installation and Configuration Guide
# Additional information may be useful during debugging
print start_html('Cookie Tester');
if (!$ExistingHostCookie) {
print "No cookie named $SLBCookie existed<br>\n";
print "It was set to the local host address of $HostIPAddr<br>\n";
}
elsif ($ExistingHostCookie ne $HostIPAddr) {
print "The cookie named $SLBCookie was set for host
$ExistingHostCookie<br>\n";
print "It was reset to the local host address of $HostIPAddr<br>\n";
}
else {
print "The cookie named $SLBCookie was correctly set to
$ExistingHostCookie<br>\n";
print "No action was taken<br>\n";
}
print end_html;
Hashed Cookie Persistence
Using hashed cookie persistence, unique information about the client is placed in the
cookie. When the application switch examines the cookie, it performs a mathematical
hash of the unique contents of the cookie. The mathematical hash operation always
renders the same numeric value for the cookie. In other words, a given cookie is always
forwarded to the same server until the size of the server pool changes.
Figure 6-3 illustrates hashed cookie persistence.