HP-UX の TCP/IP チューニング・パラメータ

TCP のチューニング・パラメータは、ndd コマンドで取得できます。

> ndd -h supported /dev/tcp
SUPPORTED ndd tunable parameters on HP-UX:

IP:
    ip_def_ttl            -  Controls the default TTL in the IP header
    ip_forward_directed_broadcasts -  Controls subnet broadcasts packets
    ip_forward_src_routed -  Controls forwarding of source routed packets
    ip_forwarding         -  Controls how IP hosts forward packets
    ip_fragment_timeout   -  Controls how long IP fragments are kept
    ip_icmp_return_data_bytes -  Maximum number of data bytes in ICMP
    ip_ill_status         -  Displays a report of all physical interfaces
    ip_ipif_status        -  Displays a report of all logical interfaces
    ip_ire_hash           -  Displays all routing table entries, in the order
                               searched when resolving an address
    ip_ire_status         -  Displays all routing table entries
    ip_ire_cleanup_interval  - Timeout interval for purging routing entries
    ip_ire_flush_interval    - Routing entries deleted after this interval
    ip_ire_gw_probe_interval - Probe interval for Dead Gateway Detection
    ip_ire_pathmtu_interval  - Controls the probe interval for PMTU
    ip_ire_redirect_interval - Controls 'Redirect' routing table entries
    ip_pmtu_strategy      -  Controls the Path MTU Discovery strategy
    ip_reass_mem_limit    -  Maximum number of bytes for IP reassembly
    ip_send_redirects     -  Sends ICMP 'Redirect' packets
    ip_send_source_quench -  Sends ICMP 'Source Quench' packets
    ip_strong_es_model    -  Controls support for 'Strong End-System Model'
    ip_udp_status         -  Reports IP level UDP fanout table

TCP:
    tcp_conn_request_max     -  Max number of outstanding connection request
    tcp_ignore_path_mtu      -  Disable setting MSS from ICMP 'Frag Needed'
    tcp_ip_abort_cinterval   -  R2 during connection establishment
    tcp_ip_abort_interval    -  R2 for established connection
    tcp_ip_notify_cinterval  -  R1 during connection establishment
    tcp_ip_notify_interval   -  R1 for established connection
    tcp_ip_ttl               -  TTL value inserted into IP header
    tcp_keepalive_detached_interval - Send keepalive probes for detached TCP
    tcp_keepalive_interval   -  Interval for sending keepalive probes
    tcp_largest_anon_port    -  Largest anonymous port number to use
    tcp_recv_hiwater_def     -  Maximum receive window size
    tcp_recv_hiwater_lfp     -  Maximum receive window size for fast links
    tcp_recv_hiwater_lnp     -  Maximum receive window size for slow links
    tcp_rexmit_interval_initial - Initial value for round trip time-out
    tcp_rexmit_interval_initial_lnp - tcp_rexmit_interval_initial for LNP
    tcp_rexmit_interval_max  -  Upper limit for computed round trip timeout
    tcp_rexmit_interval_min  -  Lower limit for computed round trip timeout
    tcp_sth_rcv_hiwat        -  Sets the flow control high water mark
    tcp_sth_rcv_lowat        -  Sets the flow control low water mark
    tcp_syn_rcvd_max         -  Controls the SYN attack defense of TCP
    tcp_status               -  Get netstat-like TCP instances information
    tcp_time_wait_interval   -  How long stream persists in TIME_WAIT
    tcp_xmit_hiwater_def     -  The amount of unsent data that triggers
                                  TCP flow control
    tcp_xmit_hiwater_lfp     -  The amount of unsent data that triggers
                                  TCP flow control for fast links
    tcp_xmit_hiwater_lnp     -  The amount of unsent data that triggers
                                  TCP flow control for slow links
    tcp_xmit_lowater_def     -  The amount of unsent data that relieves
                                  TCP flow control
    tcp_xmit_lowater_lfp     -  The amount of unsent data that relieves
                                  TCP flow control for fast links
    tcp_xmit_lowater_lnp     -  The amount of unsent data that relieves
                                  TCP flow control for slow links

UDP:
    udp_def_ttl              -  Default TTL inserted into IP header
    udp_largest_anon_port    -  Largest anonymous port number to use
    udp_status               -  Get UDP instances information.

RAWIP:
    rawip_def_ttl            -  Default TTL inserted into IP header

ARP:
    arp_cache_report         -  Displays the ARP cache
    arp_cleanup_interval     -  Controls how long ARP entries stay in the
                                  ARP cache

> ndd /dev/tcp  tcp_time_wait_interval
60000

> ndd -set /dev/tcp  tcp_time_wait_interval 1000

チューニング・パラメータ一覧表

以下に機能別のチューニング・パラメータを列挙します。
時間間隔の単位はミリ秒で、サイズの単位はバイトです。

パラメータ	意　　　　　　　味	既定値	設定可能値
tcp_conn_request_max	接続確立時の接続中のキュー最大サイズ	20	[1,-]
tcp_ignore_path_mtu	ICMP からの MSS を無視する	0	0/1
tcp_ip_abort_cinterval	接続時、RESET を送信するまでの時間	75000	[1000,-]
tcp_ip_abort_interval	接続完了後、RESET を送信するまでの時間	600000	[500,-]
tcp_ip_notify_cinterval	アクティブ・オープン時ルートを決めるまでの時間	10000	[1000,-]
tcp_ip_notify_interval	接続確立時ルートを決めるまでの時間	10000	[500,-]
tcp_ip_ttl	IP ヘッダに設定する TTL(生存時間)	64	[1,255]
tcp_keepalive_ detached_interval	デタッチしてから接続断までの時間	10000	[10000, 10243600000]
tcp_keepalive_interval	接続が維持されているか検査する時間間隔	7200000	[10000, 10243600000]
tcp_largest_anon_port	短命ポート番号最大値	65535	[1024,65535]
tcp_recv_hiwater_def	受信ウインドウサイズ最大値	32768	[4096,-]
tcp_recv_hiwater_lfp	受信ウインドウサイズ最大値(fat)	65536	[4096,-]
tcp_recv_hiwater_lnp	受信ウインドウサイズ最大値(narrow)	8192	[4096,-]
tcp_rexmit_interval_initial	最初の再送までの待時間	500	[1,20000]
tcp_rexmit_interval_initial_lnp	LNP の最初の再送までの待時間	1500	[1,20000]
tcp_rexmit_interval_max	再送待ち時間の最大値	60000	[1,7200000]
tcp_rexmit_interval_min	再送待ち時間の最小値	500	[1,7200000]
tcp_sth_rcv_hiwat	フロー制御ウインドウサイズ最大値	0	[0,128000]
tcp_sth_rcv_lowat	フロー制御ウインドウサイズ最小値	0	[0,128000]
tcp_syn_rcvd_max	再送待ち時間の最小値	500	[1,10000]
tcp_status	netstat -an のような情報を得る	-	-
tcp_time_wait_interval	TIME_WAIT で待つ時間	60000	[1000,600000]
tcp_xmit_hiwater_def	送信ウインドウサイズ	32768	[4096,-]
tcp_xmit_hiwater_lfp	高速送信ウインドウサイズ	65536	[4096,-]
tcp_xmit_hiwater_lnp	低速送信ウインドウサイズ	8192	[4096,-]