config load-balance persistence
Use this command to configure persistence rules.
Persistence rules identify traffic that should not be load balanced, but instead forwarded to the same backend server that has seen requests from that source before. Typically, you configure persistence rules to support server transactions that depend on an established client-server session, like e-commerce transactions or SIP voice calls.
The system maintains persistence session tables to map client traffic to backend servers based on the session attribute specified by the persistence rule.
The persistence table is evaluated before load balancing rules. If the packets received by the ADC match an entry in the persistence session table, the packets are forwarded to the server that established the connection, and load balancing rules are not applicable.
Most persistence rule types have a timeout. When the time that has elapsed since the system last received a request from the client IP address is greater than the timeout, the system does not use the mapping table to forward the request. Instead, it again selects the server using the method specified in the virtual server configuration. Hash-based rule types have a timeout built into the hash algorithm. For other types, you can specify the timeout.
Table 9 describes the predefined persistence rules. You can get started with these commonly used persistence methods or create custom objects.
| Predefined | Description |
|---|---|
|
LB_PERSIS_SIP |
Persistence based on source IP address or subnet. |
|
LB_PERSIS_CONSISTENT_SIP |
Persistence based on a hash of source IP address. |
|
LB_PERSIS_HASH_SRC_ADDR_PORT |
Persistence based on a hash that includes source IP address and port. |
|
LB_PERSIS_HASH_COOKIE |
Persistence based on a hash of a session cookie provided by the backend server. |
| LB_PERSIS_RDP_COOKIE | Persistence based on RDP cookie sent by RDP clients in the initial connection request. |
|
LB_PERSIS_SSL_SESS_ID |
Persistence based on the SSL session ID. |
| LB_PERSIS_SIP_CALL_ID |
Persistence based on the SIP call ID. |
Before you begin:
- You must have a good understanding and knowledge of the applications that require persistent sessions and the methods that can be used to identify application sessions.
- You must have read-write permission for load balancing settings.
After you have configured a persistence rule, you can select it in the virtual server configuration.
Syntax
config load-balance persistence
edit <name>
set type {consistent-hash-ip | embedded-cookie | hash-cookie | hash-http-header | hash-http-request | hash-source-address-port | insert-cookie | persistent-cookie | radius-attribute | rdp-cookie | rewrite-cookie | source-address | ssl-session-id}
set timeout <integer>
set keyword <string>
set match-across-servers {enable|disable}
set ipv4-maskbits <integer>
set ipv6-maskbits <integer>
set override-connection-limit {enable|disable}
set radius-attribute-relation {AND|OR}
config radius-attribute
edit <No.>
set type {1-user-name | 4-nas-ip-address | 5-nas-port | 6-service-type | 7-framed-protocol | 8-framed-ip-address | 9-framed-ip-netmask | 12-framed-mtu | 13-framed-compression | 14-login-ip-host | 19-callback-number | 24-state | 26-vendor-specific | 30-called-station-id | 31-calling-station-id | 32-nas-identifier | 33-proxy-state | 34-login-lat-service | 35-login-lat-node | 36-login-lat-group | 60-chap-challenge | 61-nas-port-type | 62-port-limit | 63-login-lat-port}
set vendor-id <integer>
set vendor-type <integer>
next
end
next
end
|
type |
Specify the persistence type:
After you have specified the type, the CLI commands are constrained to the ones that are applicable to the specified type, not all of the settings described in this table. |
|
timeout |
Timeout for an inactive persistence session table entry. The default is 300 seconds. The valid range is 1-86,400. When the time that has elapsed since the system last received a request from the client IP is greater than the timeout, the system does not use the mapping table to forward the request. Instead, it again selects the server using the method specified in the virtual server configuration. |
|
keyword |
A value found in an HTTP header or cookie. |
|
match-across-servers |
An option for radius-attribute and source-address persistence methods. Enable so clients continue to access the same backend server through different virtual servers for the duration of a session. |
|
ipv4-maskbits |
Number of bits in a subnet mask to specify a network segment that should following the persistence rule. For example, if IPv4 maskbits is set to 24, and the backend server A responds to a client with the source IP 192.168.1.100, server A also responds to all clients from subnet 192.168.1.0/24. |
|
ipv6-maskbits |
Number of bits in a subnet mask to specify a network segment that should following the persistence rule. |
|
override-connection-limit |
An option for radius-attribute only. Disabled by default. If the real server connection limit is reached and this option is enabled, the new connection will neither persist to the new server nor go to another node. |
|
radius-attribute-relation |
An option for radius-attribute only. The relation when multiple radius attributes are configured. AND—All of the specified radius attributes must be the same in the hash table to be persistent. OR—Search the first radius attribute in the hash table for persistence if the first radius attribute exists. If not, search the following radius attributes in sequence. |
|
config radius-attribute |
|
|
type |
Radius attribute type. |
|
vendor-id |
An option for radius attribute type 26-vendor-specific only. The number specifies vendor id. 0 means the entire attribute will be used as a persistence input. |
|
vendor-type |
An option for radius attribute type 26-vendor-specific only. The number specifies vendor type. 0 means the entire attribute will be used as a persistence input. |