服务器上下行流量不对称，上行速度慢
2014/12/17 14:00:45点击：
问题描述
客户一台服务器通过10G网卡连接在CE6850交换机的10G电口下，该服务器从同局域网内其他服务器上通过windows文件共享下载文件速度可达100MB/s，但是上传文件速度只有110KB/s，上传速度无法接受。
处理过程
1. 排查交换机告警，该端口无告警。
2. 查看交换机接口状态，无错包：
10GE1/0/14 current state : UP (ifindex: 18)
Line protocol current state : UP
Description:
Switch Port, PVID : 1, TPID : 8100(Hex), The Maximum Frame Length is 9216
Internet protocol processing : disabled
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 3400-a305-2fe1
Port Mode: COMMON COPPER, Port Split: -
Speed: 1000, Loopback: NONE
Duplex: FULL, Negotiation: ENABLE
Mdi: AUTO, Flow-control: DISABLE
Last physical up time : 2014-12-06 10:25:37
Last physical down time : 2014-12-06 10:21:26
Current system time: 2014-12-06 10:32:57
Statistics last cleared:2014-12-06 10:06:21
Last 300 seconds input rate: 3460 bits/sec, 5 packets/sec
Last 300 seconds output rate: 180702 bits/sec, 26 packets/sec
Input peak rate 416731819 bits/sec, Record time: 2014-12-06 10:06:54
Output peak rate 2056954 bits/sec, Record time: 2014-12-06 10:06:54
Input : 3078271056 bytes, 1105836 packets
Output: 54742374 bytes, 523252 packets
Input:
Unicast: 915499, Multicast: 62
Broadcast: 715, Jumbo: 189560
Discard: 0, Frames: 0
Pause: 0
Total Error: 0
CRC: 0, Giants: 0
Jabbers: 0, Fragments: 0
Runts: 0, DropEvents: 0
Alignments: 0, Symbols: 0
Ignoreds: 0
Output:
Unicast: 503837, Multicast: 3135
Broadcast: 15899, Jumbo: 381
Discard: 0, Buffers Purged: 0
Pause: 0
Input bandwidth utilization threshold : 90.00%
Output bandwidth utilization threshold: 90.00%
Last 300 seconds input utility rate: 1.80%
Last 300 seconds output utility rate: 0.06%
3. 更换其他端口，问题依旧。
4. 该端口抓包发现，报文都是巨型帧，且几乎所有报文都一直在重传。
5. 查看服务器网卡配置，发现有一个功能是开启的：Long Send Offload.
2. 查看交换机接口状态，无错包：
10GE1/0/14 current state : UP (ifindex: 18)
Line protocol current state : UP
Description:
Switch Port, PVID : 1, TPID : 8100(Hex), The Maximum Frame Length is 9216
Internet protocol processing : disabled
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 3400-a305-2fe1
Port Mode: COMMON COPPER, Port Split: -
Speed: 1000, Loopback: NONE
Duplex: FULL, Negotiation: ENABLE
Mdi: AUTO, Flow-control: DISABLE
Last physical up time : 2014-12-06 10:25:37
Last physical down time : 2014-12-06 10:21:26
Current system time: 2014-12-06 10:32:57
Statistics last cleared:2014-12-06 10:06:21
Last 300 seconds input rate: 3460 bits/sec, 5 packets/sec
Last 300 seconds output rate: 180702 bits/sec, 26 packets/sec
Input peak rate 416731819 bits/sec, Record time: 2014-12-06 10:06:54
Output peak rate 2056954 bits/sec, Record time: 2014-12-06 10:06:54
Input : 3078271056 bytes, 1105836 packets
Output: 54742374 bytes, 523252 packets
Input:
Unicast: 915499, Multicast: 62
Broadcast: 715, Jumbo: 189560
Discard: 0, Frames: 0
Pause: 0
Total Error: 0
CRC: 0, Giants: 0
Jabbers: 0, Fragments: 0
Runts: 0, DropEvents: 0
Alignments: 0, Symbols: 0
Ignoreds: 0
Output:
Unicast: 503837, Multicast: 3135
Broadcast: 15899, Jumbo: 381
Discard: 0, Buffers Purged: 0
Pause: 0
Input bandwidth utilization threshold : 90.00%
Output bandwidth utilization threshold: 90.00%
Last 300 seconds input utility rate: 1.80%
Last 300 seconds output utility rate: 0.06%
3. 更换其他端口，问题依旧。
4. 该端口抓包发现，报文都是巨型帧，且几乎所有报文都一直在重传。
5. 查看服务器网卡配置，发现有一个功能是开启的：Long Send Offload.
根因
服务器上的LSO特性是将巨型帧的封帧工作交给底层网卡，部分服务器在Windows 7 64位专业版上该功能有时会有问题。
解决方案
在服务器上关闭LSO特性。
建议与总结
网络融合，会有越来越多的网络问题出在服务器侧，需要在定位时从多个方向入手，进行排查。
- 上一篇：S5700交换机下面用户获取IP地址比较慢 2014/12/17
- 下一篇：S3300 web登录后只能执行ping和tracert操作 2014/12/17