MTU協(xié)商不一致導(dǎo)致線路周期性丟包一、網(wǎng)絡(luò)拓撲情況，二、網(wǎng)絡(luò)大致情況說明：該網(wǎng)絡(luò)采用思科4507交換機作為該單位網(wǎng)絡(luò)核心交換機設(shè)備，因前期施工和后期成本等問題，導(dǎo)致該網(wǎng)絡(luò)到互聯(lián)網(wǎng)和到上級集團公司的專線接入均在一臺接入交換機原3560上，該設(shè)備和其他接入交換機一樣，上行鏈路均采用trunk方式和思科4507連接，由于對端返程路由等配置（對端接入設(shè)備的下一跳思科4507，不是接入交換機3560）問題、此臺3560接入交換機工作于透明模式。到分公司的網(wǎng)絡(luò)通過4507連接的一臺3507路由器連接。三、問題說明 因該單位網(wǎng)絡(luò)改造等原因，特用H3C的匯聚交換機5500替換原接入3650交換機所在網(wǎng)絡(luò)位置（如紅色圓圈表示），配置均采取和原接入交換機思科3560一致，該設(shè)備配置量只有上行接口trunk封裝、用戶vlan、管理地址（）、指向核心設(shè)備4507的默認(rèn)路由等。User Access VerificationPassword: 3550-bgenPassword: 3550-bg#show runBuilding configuration.Current configuration : 5028 bytes!version 12.2no service padservice timestamps debug uptimeservice timestamps log uptimeservice password-encryption!hostname 3550-bg!enable secret 5 $1$TEZy$Z3dYM7Yz6p4tR4pfzj9O6.enable password 7 094F471A1A0A!username ciscono aaa new-modelsystem mtu routing 1500ip subnet-zeroip routing!no file verify autospanning-tree mode pvstspanning-tree extend system-id!vlan internal allocation policy ascending!interface FastEthernet0/1 description internet switchport access vlan 2 switchport mode access!interface FastEthernet0/2 description guangyuwang switchport access vlan 2 switchport mode access!interface FastEthernet0/3 switchport access vlan 2 switchport mode access!interface FastEthernet0/4 switchport access vlan 2 switchport mode access!interface FastEthernet0/5 switchport access vlan 3 switchport mode access!interface FastEthernet0/6 description shipinhuiyi switchport access vlan 3 switchport mode access!interface FastEthernet0/7 description BG-shebeibu switchport access vlan 2 switchport mode access!interface FastEthernet0/8 description BG-chedui switchport access vlan 2 switchport mode access!interface FastEthernet0/9 switchport access vlan 2 switchport mode access!interface FastEthernet0/10 switchport access vlan 2 switchport mode access!interface FastEthernet0/11 switchport access vlan 2 switchport mode access!interface FastEthernet0/12 switchport access vlan 2 switchport mode access!interface FastEthernet0/13 switchport access vlan 2 switchport mode access!interface FastEthernet0/14 switchport access vlan 2 switchport mode access!interface FastEthernet0/15 switchport access vlan 2 switchport mode access!interface FastEthernet0/16 switchport access vlan 2 switchport mode access!interface FastEthernet0/17 switchport access vlan 2 switchport mode access!interface FastEthernet0/18 switchport access vlan 2 switchport mode access!interface FastEthernet0/19 switchport access vlan 2 switchport mode access!interface FastEthernet0/20 switchport access vlan 2 switchport mode access!interface FastEthernet0/21 switchport access vlan 2 switchport mode access! interface FastEthernet0/22 switchport access vlan 2 switchport mode access!interface FastEthernet0/23 switchport access vlan 2 switchport mode access!interface FastEthernet0/24 switchport access vlan 2 switchport mode access!interface FastEthernet0/25 switchport access vlan 2 switchport mode access!interface FastEthernet0/26 switchport access vlan 2 switchport mode access!interface FastEthernet0/27 switchport access vlan 2 switchport mode access!interface FastEthernet0/28 switchport access vlan 2 switchport mode access!interface FastEthernet0/29 switchport access vlan 2 switchport mode access!interface FastEthernet0/30 switchport access vlan 2 switchport mode access!interface FastEthernet0/31 switchport access vlan 2 switchport mode access!interface FastEthernet0/32 switchport access vlan 2 switchport mode access!interface FastEthernet0/33 switchport access vlan 2 switchport mode access!interface FastEthernet0/34 switchport access vlan 2 switchport mode access!interface FastEthernet0/35 switchport access vlan 2 switchport mode access!interface FastEthernet0/36 switchport access vlan 2 switchport mode access!interface FastEthernet0/37 switchport access vlan 2 switchport mode access speed 100 duplex full!interface FastEthernet0/38 switchport access vlan 2 switchport mode access!interface FastEthernet0/39 switchport access vlan 2 switchport mode access speed 100 duplex full!interface FastEthernet0/40 switchport access vlan 2 switchport mode access!interface FastEthernet0/41 switchport access vlan 2 switchport mode access speed 100 duplex full!interface FastEthernet0/42 switchport access vlan 2 switchport mode access!interface FastEthernet0/43 switchport access vlan 2 switchport mode access!interface FastEthernet0/44 switchport access vlan 2 switchport mode access!interface FastEthernet0/45 switchport access vlan 2 switchport mode access!interface FastEthernet0/46 switchport access vlan 2 switchport mode access!interface FastEthernet0/47 switchport access vlan 2 switchport mode access!interface FastEthernet0/48 description HS-BG switchport trunk encapsulation dot1q switchport trunk allowed vlan 2,3 switchport mode trunk!interface GigabitEthernet0/1 description HS-BG switchport trunk encapsulation isl switchport mode trunk!interface GigabitEthernet0/2 switchport mode dynamic desirable!interface GigabitEthernet0/3 switchport mode dynamic desirable!interface GigabitEthernet0/4 switchport mode dynamic desirable!interface Vlan1 description guanli ip address !ip classlessip http server!control-plane!line con 0line vty 0 4 password 7 094F471A1A0A loginline vty 5 15 login!monitor session 1 source interface Fa0/1end3550-bg#核心交換機思科4507配置：該設(shè)備配置量為用戶網(wǎng)關(guān)、vlan配置、到集團公司、互聯(lián)網(wǎng)、分公司的靜態(tài)路由配置。Password: 4507-misenPassword: 4507-mis#show runBuilding configuration.Current configuration : 16281 bytes!version 12.2no service padservice timestamps debug uptimeservice timestamps log uptimeservice password-encryptionservice compress-configno service dhcp!hostname 4507-mis!enable password 7 110A1016141D!username ciscoip subnet-zero!spanning-tree mode pvstspanning-tree extend system-idpower redundancy-mode redundant!redundancy mode rpr!interface GigabitEthernet1/1!interface GigabitEthernet1/2!interface GigabitEthernet2/1!interface GigabitEthernet2/2!interface GigabitEthernet3/1 description HS-JK switchport trunk encapsulation isl switchport mode trunk! interface GigabitEthernet3/2 description HS-TX switchport trunk encapsulation isl switchport mode trunk!interface GigabitEthernet3/3 description HS-BG switchport trunk allowed vlan 2 switchport trunk allowed vlan add 3 switchport trunk encapsulation dot1q switchport mode trunk!interface GigabitEthernet3/4 description HS-SM-1 switchport trunk encapsulation isl switchport mode trunk!interface GigabitEthernet3/5 description HS-SM-2 switchport access vlan 3 switchport trunk encapsulation isl switchport mode access!interface GigabitEthernet3/6 switchport access vlan 4 switchport mode access!interface GigabitEthernet4/1 switchport access vlan 4 switchport mode access ip access-group 1 in!interface GigabitEthernet4/2 switchport access vlan 4 switchport mode access!interface GigabitEthernet4/3 switchport access vlan 4 switchport mode access!interface GigabitEthernet4/4 switchport access vlan 4 switchport mode access!interface GigabitEthernet4/5 switchport access vlan 4 switchport mode access!interface GigabitEthernet4/6 switchport access vlan 4 switchport mode access!interface GigabitEthernet5/1!interface GigabitEthernet5/2!interface GigabitEthernet5/3!interface GigabitEthernet5/4!interface GigabitEthernet5/5!interface GigabitEthernet5/6 switchport access vlan 4 switchport mode access!interface FastEthernet6/1 description SM switchport access vlan 3 switchport mode access!interface FastEthernet6/2 description sis switchport access vlan 3!interface FastEthernet6/3 switchport access vlan 3!interface FastEthernet6/4 description HS-BG switchport trunk encapsulation isl switchport mode trunk!interface FastEthernet6/5 switchport access vlan 4!interface FastEthernet6/6 switchport access vlan 4!interface FastEthernet6/7 description 346-2 switchport access vlan 4!interface FastEthernet6/8 switchport access vlan 4!interface FastEthernet6/9 switchport access vlan 4!interface FastEthernet6/10 switchport access vlan 4 speed 100 duplex full!interface FastEthernet6/11 description oa-server switchport access vlan 2!interface FastEthernet6/12 switchport access vlan 4!interface FastEthernet6/13 switchport access vlan 4!interface FastEthernet6/14 switchport access vlan 4!interface FastEthernet6/15 switchport access vlan 4!interface FastEthernet6/16 switchport access vlan 4!interface FastEthernet6/17 switchport access vlan 4!interface FastEthernet6/18 switchport access vlan 4!interface FastEthernet6/19 switchport access vlan 4!interface FastEthernet6/20 switchport access vlan 4!interface FastEthernet6/21 switchport access vlan 4!interface FastEthernet6/22 switchport access vlan 4!interface FastEthernet6/23 switchport access vlan 4!interface FastEthernet6/24 switchport access vlan 4!interface FastEthernet6/25 switchport access vlan 4!interface FastEthernet6/26 switchport access vlan 4!interface FastEthernet6/27 switchport access vlan 4!interface FastEthernet6/28 switchport access vlan 2!interface FastEthernet6/29 switchport access vlan 4!interface FastEthernet6/30 description beiyong-3 switchport access vlan 3!interface FastEthernet6/31 switchport access vlan 3!interface FastEthernet6/32 switchport access vlan 3!interface FastEthernet6/33 switchport access vlan 3!interface FastEthernet6/34 switchport access vlan 4!interface FastEthernet6/35 switchport access vlan 3!interface FastEthernet6/36 switchport access vlan 3!interface FastEthernet6/37 switchport access vlan 3!interface FastEthernet6/38 switchport access vlan 3!interface FastEthernet6/39 switchport access vlan 3!interface FastEthernet6/40 switchport access vlan 3!interface FastEthernet6/41 switchport access vlan 3!interface FastEthernet6/42 switchport access vlan 3!interface FastEthernet6/43 switchport access vlan 3!interface FastEthernet6/44 switchport access vlan 3!interface FastEthernet6/45 description tuoliu switchport access vlan 3!interface FastEthernet6/46 description tuoliu switchport access vlan 3!interface FastEthernet6/47 description tuoliu switchport access vlan 3!interface FastEthernet6/48 description X346-1 switchport access vlan 4!interface FastEthernet7/1 switchport access vlan 3!interface FastEthernet7/2 switchport access vlan 3!interface FastEthernet7/3 switchport access vlan 3!interface FastEthernet7/4 switchport access vlan 3! interface FastEthernet7/5 switchport access vlan 3!interface FastEthernet7/6 switchport access vlan 3!interface FastEthernet7/7 switchport access vlan 3!interface FastEthernet7/8 switchport access vlan 3!interface FastEthernet7/9 switchport access vlan 3!interface FastEthernet7/10 switchport access vlan 3!interface FastEthernet7/11 switchport access vlan 3!interface FastEthernet7/12 switchport access vlan 3!interface FastEthernet7/13 switchport access vlan 3!interface FastEthernet7/14 switchport access vlan 3!interface FastEthernet7/15 switchport access vlan 3!interface FastEthernet7/16 switchport access vlan 3!interface FastEthernet7/17 switchport access vlan 3! interface FastEthernet7/18 switchport access vlan 3!interface FastEthernet7/19 switchport access vlan 3!interface FastEthernet7/20 switchport access vlan 3!interface FastEthernet7/21 switchport access vlan 3!interface FastEthernet7/22 switchport access vlan 3!interface FastEthernet7/23 switchport access vlan 3!interface FastEthernet7/24 switchport access vlan 3!interface FastEthernet7/25 switchport access vlan 3!interface FastEthernet7/26 switchport access vlan 3!interface FastEthernet7/27 switchport access vlan 3!interface FastEthernet7/28 switchport access vlan 3!interface FastEthernet7/29 switchport access vlan 3!interface FastEthernet7/30 switchport access vlan 3! interface FastEthernet7/31 switchport access vlan 3!interface FastEthernet7/32 switchport access vlan 3!interface FastEthernet7/33 switchport access vlan 3!interface FastEthernet7/34 switchport access vlan 3!interface FastEthernet7/35 switchport access vlan 3!interface FastEthernet7/36 switchport access vlan 3!interface FastEthernet7/37 switchport access vlan 3!interface FastEthernet7/38 switchport access vlan 3!interface FastEthernet7/39 switchport access vlan 3!interface FastEthernet7/40 switchport access vlan 3!interface FastEthernet7/41 switchport access vlan 3!interface FastEthernet7/42 switchport access vlan 3!interface FastEthernet7/43 switchport access vlan 3! interface FastEthernet7/44 switchport access vlan 3!interface FastEthernet7/45 switchport access vlan 3!interface FastEthernet7/46 switchport access vlan 3!interface FastEthernet7/47 switchport access vlan 3!interface FastEthernet7/48 switchport access vlan 3!interface Vlan1 description guanli ip address !interface Vlan2 description bangong ip address 54 !interface Vlan3 description shengchan ip address !interface Vlan4 description fuwuqi ip address 54 24!interface Vlan10 description shipinjiankong ip address 54 !ip route ip route ip route 53ip route 53ip route 53ip route ip route ip route ip route ip route ip route ip http server!snmp-server community dldc RWsnmp-server enable traps snmp authentication linkdown linkup coldstart warmstartsnmp-server enable traps ttysnmp-server enable traps vtpsnmp-server enable traps vlancreatesnmp-server enable traps vlandeletesnmp-server enable traps stpxsnmp-server enable traps port-securitysnmp-server enable traps configsnmp-server enable traps entitysnmp-se