AIX网络诊断及解决现场实例

作者：lixiaolong  出处：

问题：有两台aix的测试机器，一台做应用，一台做数据库，都在同一个网段下（无双机），其中应用网络没有问题，而数据库这台网络有问题，内网下载只有30几K。 
解决方法：对比法 
由于这两台机器属于同一网段，机型完全一样，可以将两台机器的网络设置进行细致的对比，看看有何差异，然后改之。 

使用netstat -v ent0 | grep -p "Specific Statistics"命令分别查看两台机器 
应用： 
netstat -v ent0 | grep -p "Specific Statistics" 
10/100 Mbps Ethernet PCI Adapter II (1410ff01) Specific Statistics: 
-------------------------------------------------------------------- 
Link Status: Up 
Media Speed Selected: Auto negotiation 
Media Speed Running: 100 Mbps Full Duplex 
Receive Pool Buffer Size: 1024 
Free Receive Pool Buffers: 1024 
No Receive Pool Buffer Errors: 0 
Receive Buffer Too Small Errors: 0 
Entries to transmit timeout routine: 0 
Transmit IPsec packets: 0 
Transmit IPsec packets dropped: 0 
Receive IPsec packets: 0 
Receive IPsec packets dropped: 0 
Inbound IPsec SA offload count: 0 
Transmit Large Send packets: 0 
Transmit Large Send packets dropped: 0 
Packets with Transmit collisions: 
1 collisions: 0           6 collisions: 0          11 collisions: 0 
2 collisions: 0           7 collisions: 0          12 collisions: 0 
3 collisions: 0           8 collisions: 0          13 collisions: 0 
4 collisions: 0           9 collisions: 0          14 collisions: 0 
5 collisions: 0          10 collisions: 0          15 collisions: 0 
数据库： 
netstat -v ent0 | grep -p "Specific Statistics" 
10/100 Mbps Ethernet PCI Adapter II (1410ff01) Specific Statistics: 
-------------------------------------------------------------------- 
Link Status: Up 
Media Speed Selected: 100 Mbps Half Duplex 
Media Speed Running: 100 Mbps Half Duplex 
Receive Pool Buffer Size: 1024 
Free Receive Pool Buffers: 1024 
No Receive Pool Buffer Errors: 0 
Receive Buffer Too Small Errors: 0 
Entries to transmit timeout routine: 0 
Transmit IPsec packets: 0 
Transmit IPsec packets dropped: 0 
Receive IPsec packets: 0 
Receive IPsec packets dropped: 0 
Inbound IPsec SA offload count: 0 
Transmit Large Send packets: 0 
Transmit Large Send packets dropped: 0 
Packets with Transmit collisions: 
1 collisions: 233543413   6 collisions: 0          11 collisions: 0 
2 collisions: 0           7 collisions: 0          12 collisions: 0 
3 collisions: 0           8 collisions: 0          13 collisions: 0 
4 collisions: 0           9 collisions: 0          14 collisions: 0 
5 collisions: 0          10 collisions: 0          15 collisions: 0 

仔细对比发现数据库这台显然是双工模式与应用这台不同，应用的机器是自适应的，运行时是100M全双工模式，而数据库的机器限制为100M半双工模式，现在就是要将数据库这台改成与应用一样 
更改双工模式的命令为smitty chgenet 
但是在此之前要将需要更改的网卡down掉，以及所有经过此网卡的服务停止 
步骤如下： 
ifconfig -a 
输出： 
en0: flags=5e080863,80 
        inet 10.100.10.6 netmask 0xffffff00 broadcast 10.100.10.255 
再输入： 
ifconfig en0 down 
ifconfig en0 detach 
smitty chgennt 
输出： 
                                                      [Entry Fields] 
  Ethernet Adapter                                    ent0 
  Description                                         10/100 Mbps Ethernet PCI Adapter II (1410ff01) 
  Status                                              Available 
  Location                                            1L-08 
  Transmit descriptor queue size                     [512]                                                                       +# 
  Receive descriptor queue size                      [512]                                                                       +# 
  Software transmit queue size                       [8192]                                                                      +# 
  Receive buffer pool size                           [1024]                                                                      +# 
  Media Speed                                         Auto_Negotiation                                                           + 
  IPsec Offload                                       no                                                                         + 
  Enable hardware transmit and receive checksum       yes                                                                        + 
  Enable TCP Large Send Offload                       no                                                                         + 
  Enable Link Polling                                 no                                                                         + 
  Time interval for Link Polling                     [500]                                                                       +# 
  Enable ALTERNATE ETHERNET address                   no                                                                         + 
  ALTERNATE ETHERNET address                         [0x000000000000]                                                            + 
  Apply change to DATABASE only                       no                                                                         + 
更改之后需要重新设置默认网关（原来的会丢失） 
smitty tcpip 
Minimum Configuration & Startup 
输出： 
HOSTNAME                                           [TEST1-CRM-APP-CLS] 
* Internet ADDRESS (dotted decimal)                  [10.100.10.6] 
  Network MASK (dotted decimal)                      [255.255.255.0] 
* Network INTERFACE                                   en0 
  NAMESERVER 
           Internet ADDRESS (dotted decimal)         [] 
           DOMAIN Name                               [] 
  Default Gateway 
       Address (dotted decimal or symbolic name)     [10.100.10.1] 
       Cost                                          [0]                                                                          # 
       Do Active Dead Gateway Detection?              no                                                                         + 
  Your CABLE Type                                     N/A                                                                        + 
  START TCP/IP daemons Now                            no                                                                         + 
最后将网卡启用 
ifconfig en0 up 
问题得到解决！！！！