324 lines
5.7 KiB
HTML
324 lines
5.7 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>Better manage your TCP/IP resources</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.60"><LINK
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REL="HOME"
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TITLE="Securing and Optimizing Linux"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Linux General Optimization"
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HREF="gen-optim.html"><LINK
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REL="PREVIOUS"
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TITLE="Tuning IDE Hard Disk Performance"
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HREF="chap6sec74.html"><LINK
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REL="NEXT"
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TITLE="Configuring and Building a Secure, Optimized Kernel"
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HREF="secopt-kernel.html"></HEAD
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><BODY
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CLASS="section"
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BGCOLOR="#FFFFFF"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Securing and Optimizing Linux: RedHat Edition -A Hands on Guide</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="chap6sec74.html"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 6. Linux General Optimization</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="secopt-kernel.html"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="section"
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><H1
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CLASS="section"
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><A
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NAME="AEN4895"
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>6.13. Better manage your <SPAN
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CLASS="acronym"
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>TCP/IP</SPAN
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> resources</A
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></H1
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><P
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> This hack just make the time default values for <SPAN
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CLASS="acronym"
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>TCP/IP</SPAN
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> connection lower so that more connections can be handled by time on your TCP/IP protocol. The following
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will decrease the amount of time your Linux box will try take to finish closing a connection and the amount of time before it will kill a stale connection.
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This will also turn off some <SPAN
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CLASS="acronym"
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>IP</SPAN
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> extensions that aren't needed.
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The default setup for the <SPAN
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CLASS="acronym"
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>TCP/IP</SPAN
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> parameters we'll change under Red Hat Linux are:
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<P
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></P
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><UL
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><LI
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><P
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> For the tcp_fin_timeout <TT
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CLASS="literal"
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>180</TT
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>
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</P
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></LI
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><LI
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><P
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> For the tcp_keepalive_time <TT
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CLASS="literal"
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>7200</TT
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>
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</P
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></LI
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><LI
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><P
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> For the tcp_window_scaling <TT
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CLASS="literal"
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>1</TT
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>
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</P
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></LI
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><LI
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><P
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> For the tcp_sack <TT
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CLASS="literal"
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>1</TT
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>
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</P
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></LI
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><LI
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><P
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> For the tcp_timestamps <TT
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CLASS="literal"
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>1</TT
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>
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</P
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></LI
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></UL
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>
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</P
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><P
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> To adjust the new <SPAN
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CLASS="acronym"
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>TCP/IP</SPAN
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> values, type the following commands on your terminal:
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<DIV
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CLASS="mediaobject"
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><P
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><IMG
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SRC="images/Version6.1.gif"
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ALT=""
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></IMG
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></P
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></DIV
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>
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /#<B
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CLASS="command"
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>echo</B
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> 30 >/proc/sys/net/ipv4/tcp_fin_timeout
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[root@deep] /#<B
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CLASS="command"
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>echo</B
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> 1800 >/proc/sys/net/ipv4/tcp_keepalive_time
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[root@deep] /#<B
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CLASS="command"
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>echo</B
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> 0 >/proc/sys/net/ipv4/tcp_window_scaling
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[root@deep] /#<B
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CLASS="command"
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>echo</B
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> 0 >/proc/sys/net/ipv4/tcp_sack
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[root@deep] /#<B
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CLASS="command"
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>echo</B
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> 0 >/proc/sys/net/ipv4/tcp_timestamps
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</PRE
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></TD
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></TR
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></TABLE
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>
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Execute the above commands and put them in your <TT
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CLASS="filename"
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>/etc/rc.d/rc.local</TT
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> file so you don't need to type them again each time your system reboots.
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</P
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><P
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> <DIV
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CLASS="mediaobject"
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><P
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><IMG
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SRC="images/Version6.2.gif"
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ALT="Version 6.2 only"
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></IMG
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></P
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></DIV
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>
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Edit the <TT
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CLASS="filename"
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>/etc/sysctl.conf</TT
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> file and add the following lines:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="programlisting"
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> # Decrease the time default value for tcp_fin_timeout connection
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net.ipv4.tcp_fin_timeout = 30
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# Decrease the time default value for tcp_keepalive_time connection
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net.ipv4.tcp_keepalive_time = 1800
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# Turn off the tcp_window_scaling
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net.ipv4.tcp_window_scaling = 0
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# Turn off the tcp_sack
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net.ipv4.tcp_sack = 0
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# Turn off the tcp_timestamps
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net.ipv4.tcp_timestamps = 0
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</PRE
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></TD
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></TR
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></TABLE
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>
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You must restart your network for the change to take effect. The command to manually restart the network is the following:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# /etc/rc.d/init.d/network <B
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CLASS="command"
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>restart</B
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>
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</PRE
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></TD
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></TR
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></TABLE
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>
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<P
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CLASS="literallayout"
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><TT
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CLASS="computeroutput"
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> Setting network parameters [ OK ]
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Bringing up interface lo [ OK ]
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Bringing up interface eth0 [ OK ]
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Bringing up interface eth1 [ OK ]
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</TT
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></P
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>
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</P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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WIDTH="100%"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="chap6sec74.html"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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>Home</A
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></TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="secopt-kernel.html"
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>Next</A
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
|
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>Tuning <SPAN
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CLASS="acronym"
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>IDE</SPAN
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> Hard Disk Performance</TD
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|
><TD
|
|
WIDTH="34%"
|
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ALIGN="center"
|
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VALIGN="top"
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><A
|
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HREF="gen-optim.html"
|
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>Up</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>Configuring and Building a Secure, Optimized Kernel</TD
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></TR
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> |