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 
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！！！