AIX网络诊断及解决现场实例

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<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64BIT,CHECKSUM_OFFLOAD,PSEG,CHAIN>
        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：
                                                        [Entry Fields]
* HOSTNAME                                           [TEST1-CRM-DB-CLS]
* Internet ADDRESS (dotted decimal)                  [10.100.10.8]
  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！！！！