Sun Microsystems 1.0, Руководство пользователя

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28 SunFDDI/P 1.0 Adapter User’s Guide—May 1997
4
3. Use
ndd —set
to modify the current value of the TCP high water marks
(
tcp_xmit_hiwat
and
tcp_recv_hiwat
).
For optimum performance over FDDI connections, the TCP high water
marks should both be set to 32 Kbytes.
4. Use
ndd —get
(the default) to check the current value of the UDP high
water marks (
udp_xmit_hiwat
and
udp_recv_hiwat
).
5. Use
ndd —set
to modify the current value of the UDP high water marks
(
udp_xmit_hiwat
and
udp_recv_hiwat
).
For optimum performance over FDDI connections, the UDP high water
marks should both be set to 32 Kbytes.
▼
To Tune the Low Water Mark
By default, the low water mark is set to 2 Kbytes. Provided the high water
mark is also tuned, increasing the low water mark can improve the
performance slightly. The low water mark must never be set higher than the
high water mark. Use
ndd(1M)
to change the TCP and UDP low water marks:
1. Log in as root or become superuser.
# ndd —set /dev/tcp tcp_xmit_hiwat 32768
# ndd —set /dev/tcp tcp_recv_hiwat 32768
# ndd —get /dev/udp udp_xmit_hiwat
8192
# ndd —get /dev/udp udp_recv_hiwat
8192
# ndd —set /dev/udp udp_xmit_hiwat 32768
# ndd —set /dev/udp udp_recv_hiwat 32768