Table of Contents
Advertisement
UDP-Based DNS Health Checks
Web OS 10.0 supports UDP-based health checks along with TCP health checks, and performs
load-balancing based on TCP and UDP protocols.
DNS servers can be based on both TCP and UDP protocols. With UDP-based DNS health
checks enabled, you can send TCP-based queries to one real server group and UDP-based que-
ries to another real server group.
The health check may be performed by sending a UDP-based query (for example, for
www.nortelnetworks.com), and watching for the server's reply. The domain name to be que-
ried may be modified by specifying the content command if you need to change the
domain name.
Configuring the Switch for UDP-based Health Checks
Configure the switch to verify if the DNS server is alive.
1.
Select the real server group.
>> # /cfg/slb/group 1
2.
Set the health check type to UDP for the real server group.
>> # Real server group 1# health udpdns
3.
Set the content to domain name.
>> # Real server group 1# content <filename>|//<host><filename>|none
4.
Apply and save your configuration.
>> # Real server group 1# apply
>> # Real server group 1# save
N
OTE
query from a dummy host and watching for the server's reply. The reply, even though negative
(for example, "Server not found" since the query is from a dummy host), serves the purpose of
a health check, nonetheless.
212777-A, February 2002
–
If no host name is configured, the health check is performed by sending a UDP-based
Web OS 10.0 Application Guide
Chapter 10: Health Checking
n
233
Advertisement
Table of Contents
