Radware Alteon, Инструкция по применению

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Alteon Application Switch Operating System Application Guide
Load Balancing Special Services
282
Document ID: RDWR-ALOS-V2900_AG1302
Configuring TFTP Server Load Balancing
The following procedure is an example configuration for TFTP SLB.
To configure TFTP SLB
1. Ensure that Direct Access Mode (DAM) is enabled.
2. Ensure the virtual port for TFTP is set up for the virtual server.
3. To make your configuration changes active, apply your changes.
Lightweight Directory Access Server SLB
As defined in RFC 2251, Lightweight Directory Access Protocol (LDAP) is an application-level protocol
between LDAP clients and servers, which allows clients to retrieve LDAP directory entries via the
Internet. The client sends a protocol operation request to the server and the server responds with a
response. If it is based on TCP, port 389 is used. Once a connection is set up between the client and
server, the client issues operations to the server, and the server sends responses back to the client.
Before LDAP directory operations can be issued, usually a bind operation is first issued in which
authorization is also sent.
LDAP Operations and Server Types
There are two kinds of LDAP operations: read and write. Clients use read operations to browse
directories on servers, and use write operations to modify a directory on a server. There are two
types of LDAP servers: read and write servers. Read servers only conduct read operations, and write
servers perform both read and write operations.
How LDAP SLB Works
An LDAP connection is set up via Layer 4 load balancing and is bound to a read server. After that,
operation frames received by Alteon are checked at Layer 7 to determine if there are any write
operations. The bind and write operation data frames are stored for potential later use. When a write
operation arrives, Alteon disconnects the connection to the read server and re-initiates another
connection with the write server without the client's knowledge. Once the connection is set up with
the write server, all the later requests go to the write server until an unbind request is received by
Alteon. All these operations occur within one TCP connection.
After the reset is sent to the old server, a connection is set up to the new server. Stored data frames
are forwarded to the server. After the write operation is forwarded to the server, the connection is
spliced.
Selectively Resetting a Real Server
If a long-lived LDAP connection exceeds Alteon's maximum session length (32,768 minutes), the
session ages out before the LDAP connection is closed. Alteon may then create another session to
accept the same connection data. To prevent this, Alteon can be configured to send a reset to a real
server whose session has timed out before the LDAP connection is closed.
>> # /cfg/slb/virt 1/service tftp
>> Virtual Server 1 69 tftp Service# apply