交換機(jī)端口錯(cuò)包排查方法

1、wd一、重要性：從網(wǎng)維排查的用戶反應(yīng)網(wǎng)速慢的故障中，相當(dāng)一部分是山于交換機(jī)和交換機(jī)端 口、交換機(jī)端口和用戶路山器端口、交換機(jī)端口和光電轉(zhuǎn)換器端口、交換機(jī)端口 和用戶網(wǎng)卡匹配不當(dāng)，產(chǎn)生錯(cuò)包引起的。該問(wèn)題雖然比較常見(jiàn)，但只要按交換機(jī) 開(kāi)局來(lái)配置，通常能降低故障發(fā)生率，即使還存在端口錯(cuò)包問(wèn)題，也能通過(guò)改端 口速度和雙工狀態(tài)來(lái)徹底解決。二、交換機(jī)端口錯(cuò)包說(shuō)明：以華為交換機(jī)端口為例進(jìn)行說(shuō)明：NJ-A-GJXC-S3026C-1dis int eth 0/1Ethernet0/1 current state : UPIP Sen ding Frames Format is PKTFMT_ETHNT_2,

2、Hardware address is 000f-e21d-bedcDescription: to gujiao_33-192.168.86.161The Maximum Transmit Unit is 1500Media type is twisted pair, loopback not setPort hardware type is 100_BASE_TX100Mbps-speed mode, full-duplex modeLink speed type is force link，link duplex type is force linkFlow-control is not

3、enabledPort-flow-constrain has not been configured completelyThe Maximum Frame Length is 1536Broadcast MAX-ratio: 100%PVID: 10Mdi type: autoPort link-type: hybridTagged VLAN ID : , 99Untagged VLAN ID : , 10, 458Last 300 sec onds in put: 0 packets/sec 11 bytes/secLast 300 sec onds output: 7 packets/s

4、ec 520 bytes/secInput(total): 11864483 packets, 6684922188 bytes66707 broadcasts, 9522 multicastslnput(normal): packets, bytes broadcasts, multicastsInput: 0 in put errors, 0 runts, 0 giants, throttles, 0 CRC0 frame, overruns，0 aborts, 0 ignored, parity errorsOutput(total): 12008069 packets, 5178275

5、457 bytes3638352 broadcasts, 288120 multicasts, 0 pausesOutputfnormal): packets, bytes broadcasts, multicasts, - pausesOutput: 0 output errors, underruns, buffer failureswd0 aborts, 0 deferred, 0 collisions, 0 late collisions0 lost carrier, no carrier如上紅字所示：輸入錯(cuò)誤數(shù)，input errors等于各種重要錯(cuò)誤信息的總和。不同的產(chǎn)品可以根據(jù)

6、具體情況增加其它參數(shù)，或減少不能實(shí)現(xiàn)的參數(shù)。1. Runts: discarded packets that are smaller than the mediums minimum packet size.（Receive Byte Count 64 and NOT CRC Erroror Receive Byte Count 1518 and NOT CRC Erroror Receive Byte Count 1522 and Tag Packet and NOT CRC Error,沒(méi)有vlan tag,數(shù)據(jù)段大于1518字節(jié)，小于最大幀長(zhǎng)度，而且沒(méi)有CRC校驗(yàn)錯(cuò) 誤的幀，和有vlan

7、 tag,數(shù)據(jù)段大于1522字節(jié)，小于最大幀長(zhǎng)度，而且沒(méi)有CRC 校驗(yàn)錯(cuò)誤的幀。）3. Throttles: discarded packets that are in complete frames.（交換機(jī)察覺(jué)緩存或CPU過(guò)載，關(guān)閉接口接收器的情形稱為throttle,是cisco 路由器上的一個(gè)概念，我們的交換機(jī)H前不具備這個(gè)功能，一般應(yīng)該顯示為不支 持。）4. CRC: discarded packets with checksum error.（Receive Packet CRC error,幀長(zhǎng)度在正常范圉（不帶tag,長(zhǎng)度在64到1518 之間，或帶tag,長(zhǎng)度在64到1522

8、之間），而且CRC校驗(yàn)錯(cuò)，如果支持此項(xiàng)， 則不支持奇偶校驗(yàn)錯(cuò)誤項(xiàng)。）5. Frame: discarded packets with frame pad/sequence/alignment error, out of frame etc.（不是整數(shù)字節(jié)，而是多17bit,因此不對(duì)齊，或亂序或空幀，而且CRC校驗(yàn) 錯(cuò)誤，但是不計(jì)入CRC錯(cuò)誤。）6.0verrun: the receiver hardware is unable to hand receiveddata to a hardware buffer because the in put rate exceeds the receiv

9、ersability to handle the data.（由于接口輸入速率超過(guò)接受方處理能力，導(dǎo)致丟包，由于我們的交換機(jī)一般 是線速轉(zhuǎn)發(fā)，這項(xiàng)一般應(yīng)該為0,只有部分交換機(jī)對(duì)上傳CPU或三層線速轉(zhuǎn)發(fā)的 幀有接口帶寬限制，或是通過(guò)ACL實(shí)現(xiàn)的帶寬限制，因此被丟棄的幀，訃入此 項(xiàng)。）7.Aborts: Input abnormal frames that are discarded.（除其他錯(cuò)誤之外，產(chǎn)品認(rèn)為有必要統(tǒng)計(jì)的錯(cuò)誤，例如前導(dǎo)碼異常的幀，計(jì)入 此項(xiàng)。）8.lg no red: packets t hat are discarded because the in terface hardw

10、are does not have eno ugh in ter nal buffers.（Packetignored,山于接口內(nèi)部buffer滿，丟棄的幀，與由于主系統(tǒng)緩存空 wd間缺乏，導(dǎo)致的丟棄幀不同。線速轉(zhuǎn)發(fā)的幀，在多接口滿帶寬輸入，單接口輸出 等情況下，山于輸出接口的帶寬不足，數(shù)據(jù)幀將內(nèi)部緩存占滿，導(dǎo)致從接口輸入 的幀在進(jìn)入內(nèi)部緩存之前被丟棄，以及進(jìn)入內(nèi)部緩存的幀超時(shí)無(wú)法輸岀，計(jì)入此 項(xiàng)，上傳到CPU的幀，曲于CPU處理能力限制，toCPU的緩存滿，導(dǎo)致被丟棄,也計(jì)入此項(xiàng)。）9.Parity: Frames with parity error（Receive Packet parit

11、y error,如果支持此項(xiàng)，則不支持CRC錯(cuò)誤項(xiàng)。）輸入丟棄數(shù)/輸入錯(cuò)誤數(shù)，output errors等于各種重要錯(cuò)誤信息的總和。不同的 產(chǎn)品可以根據(jù)具體情況增加其它參數(shù)，或減少不能實(shí)現(xiàn)的參數(shù)。1Underruns: There are no data in the output queue（Transmit under run,與Overrun相反，輸出接口的緩存從輸出隊(duì)列中取以 太網(wǎng)幀時(shí)，沒(méi)有幀，是一種非常少見(jiàn)的硬件異常。有的交換機(jī)就沒(méi)有單獨(dú)的接口 輸出緩存，與接口輸出隊(duì)列是同一塊緩存。）2. Buffer failures: Hardware does not have eno ugh

12、 in ter nal buffers （內(nèi)部緩存滿，如果輸出隊(duì)列滿，輸出的以太網(wǎng)幀將在內(nèi)部緩存中暫時(shí)存儲(chǔ)，山 于內(nèi)部緩存滿，導(dǎo)致幀丟棄。由于交換機(jī)對(duì)線速轉(zhuǎn)發(fā)的數(shù)據(jù)幀發(fā)生的這種異常， 認(rèn)為只是到達(dá)內(nèi)部緩存而沒(méi)有到達(dá)出接口，是個(gè)輸入幀，因此計(jì)入Input IgnoredError,只有從CPU發(fā)出的幀，山于內(nèi)部緩存滿，導(dǎo)致幀丟棄，計(jì)入此項(xiàng)。）3. Aborts: Output abnormal frames that are discarded（在半雙工模式下，由于沖突檢測(cè)，延遲發(fā)送超過(guò)15次的幀，被丟棄，計(jì)入 此項(xiàng)。除其他錯(cuò)誤之外，產(chǎn)品認(rèn)為有必要統(tǒng)訃的錯(cuò)誤，例如添加前導(dǎo)碼異常的幀, 也計(jì)入此項(xiàng)

13、）4. Deferred: The packets could not be sent out for collision under half-duplex mode （半雙工模式下，由于檢測(cè)到載波正在被聲明，當(dāng)時(shí)沒(méi)有發(fā)出的包，延時(shí)一次, 計(jì)數(shù)加一。）5. Collisions: Statistic of collision detection under half-duplex mode.（半雙工模式下，在以太網(wǎng)幀數(shù)據(jù)部分的前64字節(jié)進(jìn)入線路前，由于檢測(cè)到?jīng)_ 突，當(dāng)時(shí)沒(méi)有發(fā)出的包。）6丄ate collisions: Statistic of collision with GE port

14、sendingpackets less than 512 bytes and 10/1 OOM port less than 64 bytes.（半雙工模式下，在以太網(wǎng)幀數(shù)據(jù)部分的前64字節(jié)進(jìn)入線路后，由于檢測(cè)到?jīng)_ 突，當(dāng)時(shí)沒(méi)有發(fā)出的包。）7. Lost carrier: Statistic of losing the carrier.（載波丟失，一般適用于串行WAN接口，發(fā)送過(guò)程中，每丟失一個(gè)載波，此 計(jì)數(shù)加一，對(duì)于交換機(jī)，通常是由于線路中斷造成。）8. No carrier: Statistic of no carrier.（無(wú)載波，一般適用于串行WAN接口，當(dāng)試圖發(fā)送幀時(shí)，如果沒(méi)有載波出

15、現(xiàn)，此計(jì)數(shù)加一，對(duì)于交換機(jī)，通常是由于線路中斷造成。）如果“input errors”和“output errors”非“0”并且數(shù)字在增長(zhǎng)，通常情況下可能存 wd在端口匹配問(wèn)題，必須進(jìn)行端口狀態(tài)調(diào)整。其它廠商，cisc。和中興的二層交換機(jī)錯(cuò)包類(lèi)型相似，可以類(lèi)推。三、錯(cuò)包問(wèn)題排查方法下面分別說(shuō)下中興、華為和CISCO二層交換機(jī)排查常用命令。1.中興交換機(jī)端口排查方法，以Z2826S為例進(jìn)行說(shuō)明；交換機(jī)端口原來(lái)配置,show runwdReceivedFramesReceived Bytes CrcError InMACRcvErr Fragme nts Frames64BytesFrames1

16、28_255Bytes : 7180773Frames512_1023Bytes : 4738336OversizeFrames : 0Frames256_511 Bytes: 2203985Framesl 024_UpBytes: 29192629SendllnicastFrames : 127249246 SendNonellnicastFrames: 1892514 SendBroadcastFrames : 1035165Sen d BytesSen dFrames:4270894316:129141760SendMulticastFrames : 857349SendSingleCo

17、llision : 0SendLateCollision : 0SendCollision: 0OutPause: 0SendMultiCollision: 0SendExcessCollision : 0SendDefferTrans: 0set port 1 description To_702set port 1 auto disableset port 1 speed 10set port 1 pvid 541set port 1 macaddress on 1set port 1 unit-statistics enable交換機(jī)端口原來(lái)數(shù)據(jù)包統(tǒng)計(jì)NJ-A-CFDS-Z2826S_2

18、(1#7F)(cfg)#sh port 1 statisticsPortld: 1 PortName:128998658 ReceivedBroadcastFrames: 1815:741746864 ReceivedMulticastFrames: 0:4934296 InPause: 0:0Jabber: 2:6447228 UndersizeFrames : 0:1232457 Frames65_127Bytes : 84450478可以看到端口有大量“CrcErr。嚴(yán)錯(cuò)包，并且多次查看端口信息，可以看到錯(cuò)包在 增長(zhǎng)，該用戶當(dāng)前的上網(wǎng)速度肯定會(huì)慢，需要整改更改端口匹配模式，改成端口自適應(yīng)

19、，主動(dòng)宣告10Mset port 1 auto enableset port 1 speedadvertise speedlO fullDuplex更改后端口配置set port 1 description To_702set port 1 pvid 541set port 1 speedadvertise speedlO FullDuplexset port 1 macaddress on 1set port 1 unit-statistics enable清除原端口 1 數(shù)據(jù)包統(tǒng)計(jì)，NJ-A-CFDS-Z2826S_2(1#7F)(cfg)#clear port 1 statistics,

20、再多次查看端口狀態(tài)NJACFDSZ2826S_2(1#7F)(cfg)#sh port 1 statisticsPortld: 1 PortName:ReceivedFrames : 2377 ReceivedBroadcastFrames: 0Received Bytes: 174972ReceivedMulticastFrames: 0CrcError: 0In Pause: 0wdInMACRcvErr : 0 Fragments: 0Frames64Bytes : 4 Framesl28_255Bytes: 2Frames512_1023Bytes : 0 OversizeFrames

21、 : 0 SendUnicastFrames : 4293 SendNonellnicastFrames: 6 SendBroadcastFrames : 4 SendSingleCollision : 0 SendLateCollision : 0 SendCollision: 0OutPause: 0Jabber: 0UndersizeFrames: 0Frames65_127Bytes : 2371Frames256_511 Bytes: 0Framesl 024_UpBytes: 0SendBytes: 6461573SendFrames: 4299SendMulticastFrame

22、s : 2SendMultiCollision: 0SendExcessCollision : 0Sen dDefferTra ns可以發(fā)現(xiàn)用戶端口CrcError一直為“OS此時(shí)用戶上網(wǎng)才是正常的?？偨Y(jié)，只要2826端口有“CrcErro嚴(yán)錯(cuò)誤，一定要進(jìn)行排查，直到“CrcErro嚴(yán) 錯(cuò)誤為“0”O(jiān)2.華為二層交換機(jī)端口錯(cuò)包排查方法，以S2403H-EI為例進(jìn)行說(shuō)明 交換機(jī)端口原來(lái)配置S2403EIdis cu int eth 0/1interface Ethernet0/1description to_101speed 10duplex fullbroadcast-suppression

23、5mac-address maxmac-count 1port access vlan 456 交換機(jī)端口原來(lái)數(shù)據(jù)包統(tǒng)訃S2403EI-2dis int eth 0/1Ethernet0/1 current state : UPIP Sending Frames Format is PKTFMT_ETHNT_2, Hardware address is 000f-e22a-45fcDescription: to_101The Maximum Transmit Unit is 1500Media type is twisted pair, loopback not setPort hardwar

24、e type is 100_BASE_TX10Mbps-speed mode, full-duplex modeLink speed type is force link，link duplex type is autonegotiationFlow-control is not enabledPort-flow-c on strai n has not bee n con figured completelyThe Maximum Frame Length is 1518Broadcast MAX-ratio: 5%PVID: 456wdMdi type: normalMAX mao add

25、ress Lear ning count: 1Port link-type: accessTagged VLAN ID : noneUntagged VLAN ID : 456Last 300 sec onds in put: 29 packets/sec 5729 bytes/secLast 300 seconds output: 22 packets/sec 3705 bytes/secInput(total): 33659824 packets, 8999990068 bytes16038 broadcasts, 175 multicastsIn put (n ormal): 33659

26、823 packets, bytes16038 broadcasts, 175 multicastsInput: 1102 input errors, 0 runts, 0 giants, throttles, 112 CRC0 frame, overruns，0 aborts, 2637 ignored， parity errorsOutput(total): 36569492 packets, bytes1404710 broadcasts, 5025215 multicasts, 0 pausesOutput(normal): 36569492 packets, bytes1404710

27、 broadcasts, 5025215 multicasts, pausesOutput: 0 output errors, underruns, buffer failures19947 aborts, 0 deferred, 0 collisions, 0 late collisions lost carrier, no carrier端口有1102個(gè)“input errors”，說(shuō)明端口匹配有問(wèn)題，需要進(jìn)行排查。 更改端口匹配模式，改成端口指定10M, duplex自適應(yīng)duplex auto更改后端口配置interface Ethernet0/1description to_101s

28、peed 10broadcast-suppression 5mac-address maxmac-count 1port access vlan 456 清除原端口 1數(shù)據(jù)包統(tǒng)汁，再多次查看端口狀態(tài)，需要從“#”模式退到“”模 式S2403EIquit reset counters int eth 0/1S2403EIdis int eth 0/1Ethernet0/1 current state : UPIP Sending Frames Format is PKTFMT_ETHNT_2, Hardware address is000f-e22a-45fcDescription: to_10

29、1wdThe Maximum Transmit Unit is 1500Media type is twisted pair, loopback not setPort hardware type is 100_BASE_TX10Mbps-speed mode, full-duplex modeLink speed type is force link, link duplex type is autonegotiation Flow-control is not enabledPort-flow-constrain has not been configured completelyThe

30、Maximum Frame Length is 1518Broadcast MAX-ratio: 5%PVID: 456Mdi type: normalMAX macaddress Learning count: 1Port link-type: accessTagged VLAN ID : noneUntagged VLAN ID : 456Last 300 sec onds in put: 28 packets/sec 5804 bytes/secLast 300 sec onds output: 27 packets/sec 4880 bytes/secInput(total): 336

31、72483 packets, 9002467028 bytes16038 broadcasts, 175 multicastsInput(normal): 33672482 packets, bytes16038 broadcasts, 175 multicastsIn put: 0 in put errors, 0 run ts, 0 gian ts, throttles, 0 CRC0 frame, - overruns，0 aborts, 0 ignored, parity errors Output(total): 36580860 packets, bytes1404792 broa

32、dcasts, 5025466 multicasts, 0 pausesOutput(normal): 36580860 packets, bytes1404792 broadcasts, 5025466 multicasts, pausesOutput: 0 output errors, underruns, buffer failures0 aborts, 0 deferred, 0 collisions, 0 late collisions lost carrier, no carrier如果再多次查看端口狀態(tài)，看到“input errors為“0”，此時(shí)用戶上網(wǎng)速度才正常。3. CIS

33、CO二層交換機(jī)端口錯(cuò)包排查方法，以C2950為例進(jìn)行說(shuō)明 交換機(jī)端口原來(lái)配置2950#sh ru int fa0/3interface FastEthernet0/3description testswitchport access vlan 100no ip addressduplex fullspeed 100end 交換機(jī)端口原來(lái)數(shù)據(jù)包統(tǒng)汁，wd2950#sh intfa0/3FastEthernet0/3 is up，line protocol is up (connected)Hardware is Fast Ethernet, address is 000d.bd98.1c43 (

34、bia 000d.bd9&1c43) Description: testMTU 1500 bytes, BW 100000 Kbit, DLY 1000 usee,reliability 255/255, txload 1/255, rxload 1/255Encapsulation ARPA, loopback not setKeepalive set (10 sec)Full-duplex, 100Mb/sin put flow-c ontrol is off, output flow-c on trol is offARP type: ARPA, ARP Timeout 04:00:00

35、Last in put n ever, output 00:00:01, output hang n everLast clean ng of show interface counters 21w6dIn put queue: 0/75/0/0 (size/max/drops/f lushes); Total output drops: 0 Queueing strategy: fifoOutput queue :0/40 (size/max)5 minute in put rate 0 bits/sec, 0 packets/sec5 minute ouxtput rate 0 bits/

36、sec, 0 packets/sec330574221 packets input, 78353246 bytes, 0 no buffer Received 372 broadcasts, 0 runts, 0 giants, 0 throttles 3540 input errors, 3540 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause in put0 in put packets with dribble condition detected307917156 packets output, 1

37、76359999 bytes, 0 underruns0 output errors, 0 collisions，0 interface resets0 babbles, 0 late collision，0 deferred0 lost carrier, 0 no carrier, 0 PAUSE output0 output buffer failures, 0 output buffers swapped out端口有3540個(gè)“input errors”，說(shuō)明端口匹配有問(wèn)鼠 需要進(jìn)行排查。 更改端口匹配模式，改成端口雙工狀態(tài)duplex自適應(yīng)duplex auto更改后端口配置2950

38、#sh ru int fa0/3interface FastEthernet0/3description test switchport access vlan 100 no ip address speed 100 end 清除原端口1數(shù)據(jù)包統(tǒng)計(jì)，再多次查看端口狀態(tài)2950#clear counters fa0/3Clear show interface counters on this interface confirm回車(chē)確認(rèn) sw4-idc#sh int faO/3FastEthernet0/3 is up； line protocol is up (connected)Hardwar

39、e is Fast Ethernet, address is 000d.bd98.1c43 (bia 000d.bd98.1c43) Description: HeHai-SyslogServer-218.104.84.114_5#B03wdMTU 1500 bytes, BW 100000 Kbit, DLY 1000 usee,wd2826(cfg)#show run#查看設(shè)備配置文件#2826(cfg)#sh port 1 statistics 2826(cfg)#set port 1 auto enable#查看端口數(shù)據(jù)統(tǒng)訃信息#改成端口自適應(yīng)#2826(cfg)#clear port

40、 1 statistics2.華為二層交換機(jī)常用命令 S2403EIdis cu int eth 0/1 S2403EIdis int eth 0/1 S2403EIint eth 0/1Speed 10duplex auto#清除原端口 1數(shù)據(jù)包統(tǒng)訃reliability 255/255, txload 1/255, rxload 1/255Encapsulation ARPA, loopback not setKeepalive set (10 sec)Full-duplex, 100Mb/sin put flow-c on trol is off, output flow-c on trol is offARP type: ARPA, ARP Timeout 04:00:00Last in put n ever, output 00:00:01, output hang n ever