<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:content="http://purl.org/rss/1.0/modules/content/">
  <channel>
    <title>Network on kamuszhou&#39;s blog</title>
    <link>https://ykyi.net/tags/network/</link>
    <description>Recent content in Network on kamuszhou&#39;s blog</description>
    <generator>Hugo</generator>
    <language>zh-cn</language>
    <lastBuildDate>Fri, 23 Nov 2018 08:45:32 +0000</lastBuildDate>
    <atom:link href="https://ykyi.net/tags/network/index.xml" rel="self" type="application/rss+xml" />
    <item>
      <title>netstat -s统计输出的所有字段详细解释</title>
      <link>https://ykyi.net/?p=1557/</link>
      <pubDate>Fri, 23 Nov 2018 08:45:32 +0000</pubDate>
      <guid>https://ykyi.net/?p=1557/</guid>
      <description>&lt;p&gt;今天工作上碰到一个问题需要知道udp的丢包数据。实际上我不相信能简单地得到udp的丢包精确数据。理由是，网卡负载太高时有些包连网卡都没收到，根本不可能来得及汇报给内核。另外，如果是路由器把udp丢了，那udp的目的端机器当然更不可能感知到有丢包了。&lt;/p&gt;
&lt;p&gt;这时，同事说netstat -us (–statistic)可以看到udp的丢包。这里的u选项指的是只展示udp相关的统计，s选项自然表示的是统计了。如果不用u选项，则出显示所有统计数据。下面是我的机器上的输出。&lt;/p&gt;
&lt;pre&gt;&lt;code class=&#34;language-bash &#34;&gt;Ip:
    203440255187 total packets received
    0 forwarded
    0 incoming packets discarded
    201612429535 incoming packets delivered
    1064529177 requests sent out
    15 fragments dropped after timeout
    3058122492 reassemblies required
    1230296840 packets reassembled ok
    15 packet reassembles failed
Icmp:
    14869220 ICMP messages received
    3965512 input ICMP message failed.
    ICMP input histogram:
        destination unreachable: 6054246
        timeout in transit: 687
        echo requests: 8570532
        echo replies: 243755
    12913011 ICMP messages sent
    0 ICMP messages failed
    ICMP output histogram:
        destination unreachable: 4097869
        time exceeded: 5
        echo request: 244605
        echo replies: 8570532
IcmpMsg:
        InType0: 243755
        InType3: 6054246
        InType8: 8570532
        InType11: 687
        OutType0: 8570532
        OutType3: 4097869
        OutType8: 244605
        OutType11: 5
Tcp:
    111681768 active connections openings
    4186820 passive connection openings
    24951865 failed connection attempts
    55064041 connection resets received
    275 connections established
    1033901799 segments received
    1776166765 segments send out
    12156205 segments retransmited
    6705 bad segments received.
    106348033 resets sent
Udp:
    198894689917 packets received
    472986510 packets to unknown port received.
    1146976531 packet receive errors
    116750744 packets sent
    110301286 receive buffer errors
    0 send buffer errors
UdpLite:
TcpExt:
    423 invalid SYN cookies received
    693 packets pruned from receive queue because of socket buffer overrun
    19 packets pruned from receive queue
    11309370 TCP sockets finished time wait in fast timer
    106 packets rejects in established connections because of timestamp
    10210477 delayed acks sent
    20811 delayed acks further delayed because of locked socket
    Quick ack mode was activated 8856 times
    17118697 packets directly queued to recvmsg prequeue.
    301717551 bytes directly in process context from backlog
    152118951904 bytes directly received in process context from prequeue
    104771733 packet headers predicted
    15179703 packets header predicted and directly queued to user
    218747377 acknowledgments not containing data payload received
    102637644 predicted acknowledgments
    7293 times recovered from packet loss by selective acknowledgements
    Detected reordering 40 times using FACK
    Detected reordering 27 times using SACK
    Detected reordering 1088 times using time stamp
    476 congestion windows fully recovered without slow start
    5287 congestion windows partially recovered using Hoe heuristic
    236 congestion windows recovered without slow start by DSACK
    151673 congestion windows recovered without slow start after partial ack
    1 timeouts after reno fast retransmit
    4 timeouts after SACK recovery
    10540 timeouts in loss state
    7232 fast retransmits
    649 forward retransmits
    1871 retransmits in slow start
    11612658 other TCP timeouts
    TCPLossProbes: 93185
    TCPLossProbeRecovery: 14667
    2431 packets collapsed in receive queue due to low socket buffer
    8814 DSACKs sent for old packets
    3350 DSACKs received
    1 DSACKs for out of order packets received
    90851 connections reset due to unexpected data
    214 connections reset due to early user close
    352 connections aborted due to timeout
    TCPDSACKIgnoredNoUndo: 1571
    TCPSpuriousRTOs: 7
    TCPSackShifted: 94
    TCPSackMerged: 131
    TCPSackShiftFallback: 21183
    TCPTimeWaitOverflow: 1876775
    TCPRcvCoalesce: 15711184
    TCPOFOQueue: 3194
    TCPChallengeACK: 2337394
    TCPSYNChallenge: 13608
    TCPSpuriousRtxHostQueues: 1982796
IpExt:
    InBcastPkts: 46443933
    InOctets: 44312451521655
    OutOctets: 1915626725817
    InBcastOctets: 6827280595
&lt;/code&gt;&lt;/pre&gt;
&lt;p&gt;&lt;em&gt;喂，要是转载文章。麻烦贴一下出处 ykyi.net 采集爬虫把链接也抓走&lt;/em&gt;&lt;/p&gt;</description>
    </item>
    <item>
      <title>traceroute failed.Specify protocal traceroute used manually to fix it.</title>
      <link>https://ykyi.net/?p=751/</link>
      <pubDate>Wed, 20 Jun 2012 14:37:16 +0000</pubDate>
      <guid>https://ykyi.net/?p=751/</guid>
      <description>&lt;p&gt;&lt;span style=&#34;font-family:lucida sans unicode,lucida grande,sans-serif;&#34;&gt;&lt;span style=&#34;font-size: 16px; &#34;&gt;Today, I ran the traceroute program on a machine running FreeBSD. It failed once and again.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span style=&#34;font-family:lucida sans unicode,lucida grande,sans-serif;&#34;&gt;&lt;span style=&#34;font-size: 16px; &#34;&gt;Traceroute complained:&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span style=&#34;font-family:lucida sans unicode,lucida grande,sans-serif;&#34;&gt;&lt;span style=&#34;font-size: 16px; &#34;&gt;&lt;span style=&#34;color: rgb(51, 51, 51); line-height: 19px; text-align: left; &#34;&gt;traceroute: sendto: Permission denied.&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p style=&#34;text-align: left;&#34;&gt;
  &lt;span style=&#34;font-family:lucida sans unicode,lucida grande,sans-serif;&#34;&gt;&lt;span style=&#34;font-size: 16px; &#34;&gt;&lt;font color=&#34;#333333&#34;&gt;&lt;span style=&#34;line-height: 19px; &#34;&gt;So I tried to ping. Ping failed, too. I then checked out the configuration of the firewall, which actually denied the pass through of ICMP packet. So I set it to allow ICMP pacakges to pass through the firewall. Ping worked as I expected. But traceroute still failed.&lt;/span&gt;&lt;/font&gt;&lt;/span&gt;&lt;/span&gt;
&lt;/p&gt;</description>
    </item>
  </channel>
</rss>
