問題：有兩台aix的測試機器，一台做應用，一台做數據庫，都在同一個網段下（無雙機），其中應用網絡沒有問題，而數據庫這台網絡有問題，內網下載只有30幾K。
解決方法：對比法
由於這兩台機器屬於同一網段，機型完全一樣，可以將兩台機器的網絡設置進行細致的對比，看看有何差異，然後改之。
使用netstat -v ent0 | grep -p "Specific Statistics"命令分別查看兩台機器
應用：
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
數據庫：
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
仔細對比發現數據庫這台顯然是雙工模式與應用這台不同，應用的機器是自適應的，運行時是100M全雙工模式，而數據庫的機器限制為100M半雙工模式，現在就是要將數據庫這台改成與應用一樣
更改雙工模式的命令為smitty chgenet
但是在此之前要將需要更改的網卡down掉，以及所有經過此網卡的服務停止
步驟如下：
ifconfig -a
輸出：
en0: flags=5e080863,80
;
inet 10.100.10.6 netmask 0xffffff00 broadcast 10.100.10.255
再輸入：
ifconfig en0 down
ifconfig en0 detach
smitty chgennt
輸出：
[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
更改之後需要重新設置默認網關（原來的會丟失）
smitty tcpip
Minimum Configuration & Startup
輸出：
[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
最後將網卡啟用
ifconfig en0 up
問題得到解決！
