getnstcpparamResult Structure Definition

The getnstcpparamResult structure defines the return type for getnstcpparam API.

Syntax



Members

rc

If the method succeeds, rc is 0 else rc > 0. Values above 0x8000 indicate Warnings.

message

If the method succeeds, message is NULL else message contains Error/Warning message.

nstcpparamList

List of nstcpparams


nstcpparam Structure Definition

The nstcpparam structure defines the actual return type values for getnstcpparam API.

Syntax



Members

ws

Enable or disable window scaling.

wsval

Factor used to calculate the new window size. This argument is needed only when the window scaling is enabled.

sack

Enable or disable Selective ACKnowledgement (SACK).

learnvsvrmss

Enable or disable maximum segment size (MSS) learning for virtual servers.

maxburst

Maximum number of TCP segments allowed in a burst.

initialcwnd

Initial maximum upper limit on the number of TCP packets that can be outstanding on the TCP link to the server.

recvbuffsize

TCP Receive buffer size
NOTE: This attribute is deprecated.
This option is deprecated in favour of -buffersize

delayedack

Timeout for TCP delayed ACK, in milliseconds.

downstaterst

Flag to switch on RST on down services.

nagle

Enable or disable the Nagle algorithm on TCP connections.

limitedpersist

Limit the number of persist (zero window) probes.

oooqsize

Maximum size of out-of-order packets queue. A value of 0 means no limit.

ackonpush

Immediate ACK on PUSH packet

maxpktpermss

Maximum packets per MSS

pktperretx

Maximum packets per retransmission

minrto

Minimum retransmission timeout, in milliseconds, specified in 10-millisecond increments (value must yield a whole number if divided by 10).

slowstartincr

TCP slowstart increment factor

maxdynserverprobes

Maximum number of probes that Citrix ADC can send out in 10 milliseconds, to dynamically learn a service. Citrix ADC probes for the existence of the origin in case of wildcard virtual server or services.

synholdfastgiveup

Maximum threshold. After crossing this threshold number of outstanding probes for origin, the Citrix ADC reduces the number of connection retries for probe connections.

maxsynholdperprobe

Limit the number of client connections (SYN) waiting for status of single probe. Any new SYN packets will be dropped.

maxsynhold

Limit the number of client connections (SYN) waiting for status of probe system wide. Any new SYN packets will be dropped.

msslearninterval

Duration, in seconds, to sample the Maximum Segment Size (MSS) of the services. The Citrix ADC determines the best MSS to set for the virtual server based on this sampling. The argument to enable maximum segment size (MSS) for virtual servers must be enabled.

msslearndelay

Frequency, in seconds, at which the virtual servers learn the Maximum segment size (MSS) from the services. The argument to enable maximum segment size (MSS) for virtual servers must be enabled.

maxtimewaitconn

Maximum number of connections to hold in the TCP TIME_WAIT state on a packet engine. New connections entering TIME_WAIT state are proactively cleaned up.

kaprobeupdatelastactivity

Update last activity for KA probes
NOTE: This attribute is deprecated.
This option has been moved tcpProfile

maxsynackretx

When 'syncookie' is disabled in the TCP profile that is bound to the virtual server or service, and the number of TCP SYN+ACK retransmission by Citrix ADC for that virtual server or service crosses this threshold, the Citrix ADC responds by using the TCP SYN-Cookie mechanism.

synattackdetection

Detect TCP SYN packet flood and send an SNMP trap.

connflushifnomem

Flush an existing connection if no memory can be obtained for new connection. HALF_CLOSED_AND_IDLE: Flush a connection that is closed by us but not by peer, or failing that, a connection that is past configured idle time. New connection fails if no such connection can be found. FIFO: If no half-closed or idle connection can be found, flush the oldest non-management connection, even if it is active. New connection fails if the oldest few connections are management connections. Note: If you enable this setting, you should also consider lowering the zombie timeout and half-close timeout, while setting the Citrix ADC timeout. See Also: connFlushThres argument below.

connflushthres

Flush an existing connection (as configured through -connFlushIfNoMem FIFO) if the system has more than specified number of connections, and a new connection is to be established. Note: This value may be rounded down to be a whole multiple of the number of packet engines running.

mptcpconcloseonpassivesf

Accept DATA_FIN/FAST_CLOSE on passive subflow

mptcpchecksum

Use MPTCP DSS checksum

mptcpsftimeout

The timeout value in seconds for idle mptcp subflows. If this timeout is not set, idle subflows are cleared after cltTimeout of vserver

mptcpsfreplacetimeout

The minimum idle time value in seconds for idle mptcp subflows after which the sublow is replaced by new incoming subflow if maximum subflow limit is reached. The priority for replacement is given to those subflow without any transaction

mptcpmaxsf

Maximum number of subflow connections supported in established state per mptcp connection.

mptcpmaxpendingsf

Maximum number of subflow connections supported in pending join state per mptcp connection.

mptcppendingjointhreshold

Maximum system level pending join connections allowed.

mptcprtostoswitchsf

Number of RTO's at subflow level, after which MPCTP should start using other subflow.

mptcpusebackupondss

When enabled, if NS receives a DSS on a backup subflow, NS will start using that subflow to send data. And if disabled, NS will continue to transmit on current chosen subflow. In case there is some error on a subflow (like RTO's/RST etc.) then NS can choose a backup subflow irrespective of this tunable.

tcpmaxretries

Number of RTO's after which a connection should be freed.

mptcpimmediatesfcloseonfin

Allow subflows to close immediately on FIN before the DATA_FIN exchange is completed at mptcp level.

mptcpclosemptcpsessiononlastsfclose

Allow to send DATA FIN or FAST CLOSE on mptcp connection while sending FIN or RST on the last subflow.

mptcpsendsfresetoption

Allow MPTCP subflows to send TCP RST Reason (MP_TCPRST) Option while sending TCP RST.

mptcpfastcloseoption

Allow to select option ACK or RESET to force the closure of an MPTCP connection abruptly.

mptcpreliableaddaddr

If enabled, Citrix ADC retransmits MPTCP ADD-ADDR option if echo response is not received within the timeout interval. The retransmission is attempted only once.

tcpfastopencookietimeout

Timeout in seconds after which a new TFO Key is computed for generating TFO Cookie. If zero, the same key is used always. If timeout is less than 120seconds, NS defaults to 120seconds timeout.

builtin

Flag to determine if the tcp param is built-in or not

autosyncookietimeout

Timeout for the server to function in syncookie mode after the synattack. This is valid if TCP syncookie is disabled on the profile and server acts in non syncookie mode by default.

tcpfintimeout

The amount of time in seconds, after which a TCP connnection in the TCP TIME-WAIT state is flushed.

compacttcpoptionnoop

If enabled, non-negotiated TCP options are removed from the received packet while proxying it. By default, non-negotiated TCP options would be replaced by NOPs in the proxied packets. This option is not applicable for Citrix ADC generated packets.

delinkclientserveronrst

If enabled, Delink client and server connection, when there is outstanding data to be sent to the other side.

rfc5961chlgacklimit

Limits number of Challenge ACK sent per second, as recommended in RFC 5961(Improving TCP's Robustness to Blind In-Window Attacks)

enhancedisngeneration

If enabled, increase the ISN variation in SYN-ACKs sent by the NetScaler

sendresetreasoncode

If enabled, Sends reset reason code will be sent by the NetScaler

_nextgenapiresource


See Also