服務器(qì)上(shàng)下行(xíng)流量不對稱，上(shàng)行(xíng)速度慢
2014/12/17 14:00:45點擊：
問題描述
客戶一台服務器(qì)通(tōng)過10G網卡連接在CE6850交換機的10G電(diàn)口下，該服務器(qì)從同局域網內(nèi)其他服務器(qì)上(shàng)通(tōng)過windows文件共享下載文件速度可(kě)達100MB/s，但(dàn)是上(shàng)傳文件速度隻有(yǒu)110KB/s，上(shàng)傳速度無法接受。
處理(lǐ)過程
1. 排查交換機告警，該端口無告警。
2. 查看交換機接口狀态，無錯包：
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. 更換其他端口，問題依舊(jiù)。
4. 該端口抓包發現，報文都是巨型幀，且幾乎所有(yǒu)報文都一直在重傳。
5. 查看服務器(qì)網卡配置，發現有(yǒu)一個(gè)功能是開(kāi)啓的：Long Send Offload.
2. 查看交換機接口狀态，無錯包：
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. 更換其他端口，問題依舊(jiù)。
4. 該端口抓包發現，報文都是巨型幀，且幾乎所有(yǒu)報文都一直在重傳。
5. 查看服務器(qì)網卡配置，發現有(yǒu)一個(gè)功能是開(kāi)啓的：Long Send Offload.
根因
服務器(qì)上(shàng)的LSO特性是将巨型幀的封幀工作(zuò)交給底層網卡，部分服務器(qì)在Windows 7 64位專業版上(shàng)該功能有(yǒu)時(shí)會(huì)有(yǒu)問題。
解決方案
在服務器(qì)上(shàng)關閉LSO特性。
建議與總結
網絡融合，會(huì)有(yǒu)越來(lái)越多(duō)的網絡問題出在服務器(qì)側，需要在定位時(shí)從多(duō)個(gè)方向入手，進行(xíng)排查。
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