本檔案將提供在Cisco Catalyst 2900 XL/3500 XL或Catalyst 2950系列交換器與執行Cisco IOS®軟體的Catalyst 6500/6000交換器之間的IEEE 802.1Q/交換器間連結(ISL)主幹和第2層(L2)EtherChannel上的組態範例。在本範例中,您還可以使用執行Cisco IOS軟體而不是Catalyst 6500/6000的Catalyst 4500/4000交換器。本文討論在交換機之間配置中繼和通道時要考慮的最重要因素。本文檔還包括配置示例。
在本文中,每台交換器的四個快速乙太網路連線埠都已建立中繼並捆綁到快速EtherChannel(FEC)中。 3500 XL ISL使用中繼協定,2950示例使用802.1Q。
註:Catalyst 2950不支援ISL中繼。改用802.1Q中繼。
本文件沒有特定需求。
若要建立本檔案中的範例,以下交換器已在實驗環境中使用,且組態已清除:
執行Cisco IOS軟體版本12.0(5)WC2的Catalyst 3548 XL交換器
執行Cisco IOS軟體版本12.1(6)EA2c的Catalyst 2950-24交換器
搭載Supervisor Engine II的Catalyst 6509交換器(執行Cisco IOS軟體版本12.1(11b)E)
本文中的資訊是根據特定實驗室環境內的裝置所建立。文中使用到的所有裝置皆從已清除(預設)的組態來啟動。如果您的網路正在作用,請確保您已瞭解任何指令可能造成的影響。
如需文件慣例的詳細資訊,請參閱思科技術提示慣例。
裝置之間的中繼可以靜態配置,也可以使用動態中繼協定(DTP)配置。DTP允許連線的兩台裝置在實際建立中繼連線之前協商中繼設定。可配置的Cisco IOS軟體交換機埠(中繼)模式包括:動態(埠協商接入或中繼模式)、中繼(無條件將埠設定為中繼)和接入(非中繼接入埠)。 靜態(非DTP協商)中繼的兩端最常用的模式組合設定是trunk-trunk。對於動態(DTP協商)中繼,通常的設定是動態 — 動態。其他組合可能產生有效的結果,但不在本文檔的討論範圍之內。支援埠聚合協定(PAgP)的交換機和非PagP裝置之間的中繼連線需要開啟中繼模式。
注意:大多數Cisco路由器和某些Catalyst交換機不支援DTP並且需要靜態中繼配置。例如,Catalyst XL系列、Catalyst 2948G-L3、Catalyst 4908G-L3、Catalyst 8500系列、2/3/4/7xxx系列Cisco路由器等不支援DTP且需要靜態中繼配置。
802.1Q中繼會將4位元組的802.1Q標籤欄位插入到通過中繼傳送的幀中,該幀包含VLAN資訊。802.1Q標籤會插入到通過中繼傳輸的每個幀中,但本地VLAN上傳輸的幀除外,這些幀會以未標籤的方式傳送。大多數情況下,本徵VLAN必須在主幹的兩端都匹配,除非有特定的異常配置要求(不在本檔案的範圍之內)。如果本徵VLAN不匹配,交換機將記錄思科發現協定(CDP)消息,說明不匹配。雖然不是災難性的,但此設定實際上會導致兩個不同的本徵VLAN合併到一個更大的第2層廣播域(VLAN)中。 這兩個VLAN試圖為此類橋接的本徵VLAN計算一個通用生成樹協定(STP)拓撲,這有可能最終超過支援的最大STP直徑。
注意:當鄰居或第三方裝置要求標籤所有VLAN時,會出現特殊情況。如果發生這種情況,您可以實施一種變通方法建立虛擬VLAN並將其設定為本地VLAN。這將標籤所有其他必要的VLAN,並且它們會將流量通過中繼傳輸到鄰居或第三方裝置。在Cisco IOS軟體版本12.1.11bEX、12.1.13E及更高版本中,運行Cisco IOS軟體的Catalyst 6500支援標籤所有VLAN流量(包括本徵VLAN)的802.1Q中繼選項。在全域性配置模式下發出vlan dot1q tag native命令。在執行Cisco IOS軟體的Catalyst 4500/4000上,vlan dot1q tag native命令首先在Cisco IOS軟體版本12.2(18)EW中匯入。
交換機之間的Gigabit EtherChannel(GEC)和FEC也可使用PAgP進行靜態或動態配置。PAgP允許連線的兩台裝置在實際形成通道之前協商設定。PAgP通道模式包括:desirable(連線埠主動發起通道交涉)、auto(預設情況下,連線埠不會發起交涉,但會回應另一端啟動的交涉嘗試)和on(無條件地將連線埠設定為通道且不會交換PAgP訊框)。在支援PAgP的交換機與非PAgP裝置之間的連線需要on模式才能形成通道。
靜態(非PAgP協商)通道的兩端最常用的模式組合是開啟模式。對於動態(PAgP-negotiated)通道,通常的設定是desirable-desirable或desirable-auto。已配置為理想模式的連線埠在通道開始之前執行通道協商和驗證,並在通道運行期間繼續驗證通道。由於PAgP提供了額外的保護,如果連線的兩台交換機都支援PAgP,則通常建議採用這種設定。
注意:PAgP存在一些有意為之的配置限制。協商通道的埠必須具有相同的速度、雙工、中繼封裝和VLAN設定。此外,鏈路間的通道負載均衡演算法可以在某些平台上配置。
注意:一旦EtherChannel啟動,它就會被視為一個唯一的STP埠。因此,要在設定非協商通道時避免STP不一致,請按照以下步驟操作:
關閉通道的所有埠以在兩端進行配置。
在兩端執行配置。
重新啟用所有埠。
在連線埠開啟時嘗試設定此類通道可能會導致臨時STP不一致和/或回圈。這些步驟僅在未使用PAgP時適用。
Catalyst 2900 XL/3500 XL
Catalyst 2900 XL/3500 XL系列交換器不支援DTP和PAgP,因此需要靜態主幹和通道設定。有關更多資訊,請參閱上述說明。Catalyst 2900 XL/3500 XL系列交換器目前支援ISL和802.1Q中繼封裝。如需詳細資訊,請參閱以下檔案:
Cisco IOS軟體版本11.2(8)SA4和更新版本支援ISL,而Cisco IOS軟體版本11.2(8)SA5和更新版本支援802.1Q。
使用執行Cisco IOS軟體版本11.2(8)SA1或11.2(8)SA2的Catalyst 2900 XL,每台交換器允許四個EtherChannel(連線埠群組),且每個群組的連線埠數不受限制。通道中鏈路間的負載均衡始終基於目標地址。不支援交換式連線埠分析器(SPAN)和連線埠安全功能。
在執行Cisco IOS軟體版本11.2(8)SA3或更新版本的Catalyst 2900 XL、執行Cisco IOS軟體版本11.2(8)SA6或更新版本的Catalyst 3500 XL和Catalyst 2950上,通道中連結間的負載平衡可以設定為基於來源或目的地MAC位址。Source是預設值。基於源的轉發允許一個FEC(埠組)中最多八個埠。 基於目標的轉發允許每個埠組有無限的埠。每台交換機最多可以配置12個埠組,並且可以混合使用基於源/目標的組。不支援SPAN和埠安全。
Catalyst 2950
Catalyst 2950交換機僅支援802.1Q中繼,不支援ISL中繼。Catalyst 2950交換器支援DTP和PAgP動態中繼和通道交涉(使用Cisco IOS軟體版本12.1版本),以及靜態模式(僅使用Cisco IOS軟體版本12.0版本)。EtherChannel負載平衡可以使用源MAC或目標MAC地址轉發。您可以通過發出port-channel load-balance 全域性配置命令來配置負載平衡方法。這些交換機最多支援每個通道八個交換機埠。
執行Cisco IOS軟體的Catalyst 6500
執行Cisco IOS軟體的Catalyst 6500交換器支援L2(交換器連線埠)和第3層(L3)(路由連線埠)EtherChannel組態。Catalyst 6500/6000系列交換器最多支援64個EtherChannel(使用Cisco IOS軟體版本12.1(2)E和更新版本時為256個)。 您可以形成EtherChannel,在Catalyst 6000系列交換器中的任何模組上最多具有八個相容設定的LAN連線埠,但配備數位功能卡(DFC)的模組(例如WS-X6816等)除外,目前這些模組僅允許使用同一DFC模組上的連線埠來建立L2通道。但是,可以在不同的配備DFC的模組之間配置L3通道。Catalyst 6500/6000 Cisco IOS軟體版本12.1(11b)EX和更新版本已移除此限制。本文檔配置二層EtherChannel。
執行Cisco IOS軟體的Catalyst 6500/6000允許您發出port-channel load-balance 全域組態命令,設定EtherChannel負載平衡,以使用任何來源、目的地和來源 — 目的地組合中的MAC位址、IP位址或第4層(L4)連線埠資訊。預設設定為在源IP地址和目標IP地址之間使用雜湊函式。
Catalyst 6500/6000交換機支援ISL和802.1Q中繼封裝以及DTP。有關埠功能的詳細資訊,請發出show interface interface_id capabilities命令。
執行Cisco IOS軟體的Catalyst 4000
執行Cisco IOS軟體(搭載Supervisor Engine III和IV)的Catalyst 4000交換器支援L2(交換器連線埠)和L3(路由連線埠)EtherChannel組態。Catalyst 4000系列交換器最多支援64個EtherChannel。您可以形成EtherChannel,在任何模組上,以及在Catalyst 4000系列交換機中的模組上,配置最多八個相容的乙太網介面。每個EtherChannel中的所有介面都必須為相同的速度,並且必須全部配置為L2或L3介面。
執行Cisco IOS軟體的Catalyst 4000允許您設定EtherChannel負載平衡,透過發出port-channel load-balance 全域組態命令,在任何來源、目的地和來源 — 目的地組合中使用MAC位址、IP位址或L4連線埠資訊。預設設定為在源IP地址和目標IP地址之間使用雜湊函式。
運行Cisco IOS軟體的Catalyst 4000支援ISL和802.1Q中繼封裝和DTP。ISL在某些模組上不可用。如需此類模組的完整清單,請參閱設定第2層乙太網路介面的瞭解VLAN中繼一節。在未來的軟體版本中,通過發出show interface capabilities命令可獲得有關埠功能的詳細資訊。目前此命令不可用。
本節提供用於設定本文件中所述功能的資訊。
注意:要查詢有關本文檔中使用的命令的其他資訊,請使用命令查詢工具 (僅限註冊客戶)。
此配置使用以下網路設定:
Catalyst 3524 XL |
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!--- Catalyst 3500 XL does not support DTP/PAgP. !--- First, shut down the secondary ports involved in the channel !--- and then enable them back when the configuration is complete on both switches. Cat3500XL#show run Building configuration... Current configuration: ! version 12.0 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Cat3500XL ip subnet-zero ! interface FastEthernet0/1 ! !--- Output suppressed. ! interface FastEthernet0/17 port group 1 !--- Assigned port to port channel 1. switchport trunk encapsulation isl !--- Configured the port to use the trunking encapsulation ISL. switchport mode trunk !--- Configured the port to be in trunking mode. ! interface FastEthernet0/18 !--- Repeated the trunk and channel configuration. port group 1 switchport trunk encapsulation isl switchport mode trunk ! interface FastEthernet0/19 !--- Repeated the trunk and channel configuration. Port group 1 switchport trunk encapsulation isl switchport mode trunk ! interface FastEthernet0/20 !--- Repeated the trunk and channel configuration. Port group 1 switchport trunk encapsulation isl switchport mode trunk ! interface FastEthernet0/21 ! !--- Output suppressed. ! interface FastEthernet0/48 ! interface GigabitEthernet0/1 ! interface GigabitEthernet0/2 ! interface VLAN1 ip address 10.10.10.1 255.255.255.0 no ip directed-broadcast no ip route-cache ! line con 0 transport input none stopbits 1 line vty 0 4 login |
Catalyst 6500(Cisco IOS軟體) |
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!--- Catalyst 3500 XL does not support DTP/PAgP. !--- First, shut down the secondary ports involved in the channel, !--- and then enable them back when the configuration is complete on both switches. Cat6500#show run Building configuration... Current configuration : 3999 bytes ! version 12.1 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Cat6500 ! boot bootldr bootflash:c6msfc2-boot-mz.121-8b.E9 ! redundancy main-cpu auto-sync standard ip subnet-zero ! ! no mls ip multicast aggregate no mls ip multicast non-rpf cef mls qos statistics-export interval 300 mls qos statistics-export delimiter | ! interface Port-channel1 !--- This interface will be created and configured automatically. !--- You do not need to input this part of the configuration. switchport switchport trunk encapsulation isl switchport mode trunk no ip address ! interface GigabitEthernet1/1 no ip address shutdown ! !--- Output suppressed. ! interface FastEthernet4/2 switchport !--- Setting the interface as an L2 port, as by default the port is a routed port. !--- Note: Catalyst 4500/4000 that runs Cisco IOS Software defaults to the L2 port. switchport trunk encapsulation dot1q !--- Setting the trunk encapsulation to dot1q. switchport mode trunk !--- Configured port to be in trunking mode. no ip address channel-group 1 mode on !--- Configured the port to participate in port channel 1 with channel mode on. ! Interface FastEthernet4/3 !--- Repeated the trunk and channel configuration. switchport switchport trunk encapsulation isl switchport mode trunk no ip address channel-group 1 mode on ! interface FastEthernet4/4 !--- Repeated the trunk and channel configuration. switchport switchport trunk encapsulation isl switchport mode trunk no ip address channel-group 1 mode on ! interface FastEthernet4/5 !--- Repeated the trunk and channel configuration. switchport switchport trunk encapsulation isl switchport mode trunk no ip address channel-group 1 mode on ! interface FastEthernet4/6 no ip address shutdown ! ! interface VLAN 1 ip address 10.10.10.2 255.255.255.0 ! ip classless no ip http server ! line con 0 line vty 0 4 ! end Cat6500# |
本節提供用於設定本文件中所述功能的資訊。
注意:要查詢有關本文檔中使用的命令的其他資訊,請使用命令查詢工具 (僅限註冊客戶)。
此配置使用以下網路設定:
Catalyst 2950 |
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!--- Catalyst 2950 with Cisco IOS Software Release 12.1 supports PAgP. !--- There is no need to shut down the ports as both Catalyst 2950 and 6500 can negotiate !--- channeling in desirable mode. Cat2950#show run Building configuration... Current configuration : 1380 bytes ! version 12.1 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Cat2950 ! ip subnet-zero no ip finger ! interface Port-channel1 switchport mode trunk ! interface FastEthernet0/1 ! interface FastEthernet0/2 switchport mode trunk !--- Configured port to be in trunking mode. channel-group 1 mode desirable !--- Configured port to participate in PAgP-negotiated port channel 1. ! interface FastEthernet0/3 !--- Repeated trunk and channel configuration. switchport mode trunk channel-group 1 mode desirable ! interface FastEthernet0/4 !--- Repeated trunk and channel configuration. switchport mode trunk channel-group 1 mode desirable ! interface FastEthernet0/5 !--- Repeated trunk and channel configuration. switchport mode trunk channel-group 1 mode desirable ! interface FastEthernet0/6 ! !--- Output suppressed. ! interface FastEthernet0/25 ! interface FastEthernet0/26 ! interface VLAN1 ip address 10.10.10.1 255.255.255.0 no ip route-cache ! ip http server ! line con 0 transport input none line vty 5 15 ! end Cat2950# |
Catalyst 6500(Cisco IOS軟體) |
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!--- Catalyst 2950 with Cisco IOS Software Release 12.1 supports PAgP. !--- There is no need to shut down the ports as both Catalyst 2950 and 6500 can negotiate !--- channeling in desirable mode. Cat6500#show run Building configuration... Current configuration : 3999 bytes ! version 12.1 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Cat6500 ! boot bootldr bootflash:c6msfc2-boot-mz.121-8b.E9 ! redundancy main-CPU auto-sync standard ip subnet-zero ! ! no mls ip multicast aggregate no mls ip multicast non-rpf cef mls qos statistics-export interval 300 mls qos statistics-export delimiter | ! interface Port-channel1 !--- This interface will be created and configured automatically. !--- You do not need to input this part of the configuration. switchport switchport trunk encapsulation dot1q switchport mode trunk no ip address ! interface GigabitEthernet1/1 no ip address shutdown ! !--- Output suppressed. ! interface FastEthernet4/2 switchport !--- Setting the interface as an L2 port, as by default the port is a routed port. !--- Note: Catalyst 4500/4000 that runs Cisco IOS Software defaults to the L2 port. switchport trunk encapsulation dot1q !--- Setting the trunk encapsulation to dot1q. switchport mode trunk !--- Configured port to be in trunking mode. No ip address channel-group 1 mode desirable !--- Configured port to participate in port channel 1 with channel mode desirable. ! Interface FastEthernet4/3 !--- Repeated trunk and channel configuration. switchport switchport trunk encapsulation dot1q switchport mode trunk no ip address channel-group 1 mode desirable ! interface FastEthernet4/4 !--- Repeated trunk and channel configuration. switchport switchport trunk encapsulation dot1q switchport mode trunk no ip address channel-group 1 mode desirable ! interface FastEthernet4/5 !--- Repeated trunk and channel configuration. switchport switchport trunk encapsulation dot1q switchport mode trunk no ip address channel-group 1 mode desirable ! interface FastEthernet4/6 no ip address shutdown ! ! interface VLAN 1 ip address 10.10.10.2 255.255.255.0 ! ip classless no ip http server ! ! line con 0 line vty 0 4 ! end Cat6500# |
使用本節內容,確認您的組態是否正常運作。
輸出直譯器工具 (僅供已註冊客戶使用)(OIT)支援某些show命令。使用OIT檢視show命令輸出的分析。
Cat3500XL#show cdp neighbor Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater Device ID Local Intrfce Holdtme Capability Platform Port ID Cat3500XL Fas 0/20 136 R S I Catalyst 6Fas 4/5 Cat3500XL Fas 0/19 136 R S I Catalyst 6Fas 4/4 Cat3500XL Fas 0/18 136 R S I Catalyst 6Fas 4/3 Cat3500XL Fas 0/17 136 R S I Catalyst 6Fas 4/2 Cat3500XL# Cat3500XL#show port group Group Interface Transmit Distribution ----- --------------------- --------------------- 1 FastEthernet0/18 source address 1 FastEthernet0/17 source address 1 FastEthernet0/20 source address 1 FastEthernet0/19 source address Cat3500XL# Cat3500XL#show etherchannel summary Flags: d - default D - down I - in use Group Ports ----- ----- 1 Fa0/18(I) Fa0/17(Id) Fa0/20(I) Fa0/19(I) Cat3500XL#
註:如果您有八埠EtherChannel,則如果執行低於Cisco IOS軟體版本12.0(5)WC5的Cisco IOS軟體版本,發出show etherchannel summary命令可能會使交換器崩潰。
Cat3500XL#show interfaces fastethernet0/17 switchport Name: Fa0/17 Switchport: Enabled Administrative mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: isl Operational Trunking Encapsulation: isl Negotiation of Trunking: Disabled Access Mode VLAN: 0 ((Inactive)) Trunking Native Mode VLAN: 1 (default) Trunking VLANs Enabled: ALL Trunking VLANs Active: 1,2 Pruning VLANs Enabled: 2-1001 Priority for untagged frames: 0 Override vlan tag priority: FALSE Voice VLAN: none Appliance trust: none Cat3500XL#
Cat6500#show interfaces fastethernet 4/2 capabilities FastEthernet4/2 Model: WS-X6248-RJ-45 Type: 10/100BaseTX Speed: 10,100,auto Duplex: half,full Trunk encap. type: 802.1Q,ISL Trunk mode: on,off,desirable,nonegotiate Channel: yes Broadcast suppression: percentage(0-100) Flowcontrol: rx-(off,on),tx-(none) Fast Start: yes QOS scheduling: rx-(1q4t), TX(2q2t) CoS rewrite: yes ToS rewrite: yes Inline power: no SPAN: source/destination Cat6500# Cat6500#show cdp neighbors Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater Device ID Local Intrfce Holdtme Capability Platform Port ID Cat6500 Fas 4/5 135 T S WS-C3548-XFas 0/20 Cat6500 Fas 4/4 135 T S WS-C3548-XFas 0/19 Cat6500 Fas 4/3 134 T S WS-C3548-XFas 0/18 Cat6500 Fas 4/2 134 T S WS-C3548-XFas 0/17 Cat6500# Cat6500#show interfaces port-channel 1 etherchannel Age of the Port-channel = 01d:07h:30m:43s Logical slot/port = 14/1 Number of ports = 4 GC = 0x00010001 HotStandBy port = null Port state = Port-channel Ag-Inuse Ports in the Port-channel: Index Load Port EC state ------+------+------+------------ 0 11 Fa4/2 on 1 22 Fa4/3 on 2 44 Fa4/4 on 3 88 Fa4/5 on Time since last port bundled: 01d:06h:51m:22s Fa4/5 Time since last port Un-bundled: 01d:06h:52m:30s Fa4/5 Cat6500# Cat6500#show etherchannel ? <1-269> Channel group number brief Brief information detail Detail information load-balance Load-balance/frame-distribution scheme among ports in port-channel port Port information port-channel Port-channel information summary One-line summary per channel-group Cat6500#show etherchannel summary Flags: D - down P - in port-channel I - stand-alone s - suspended R - Layer3 S - Layer2 U - port-channel in use Group Port-channel Ports -----+------------+----------------------------------------------------------- 1 Po1(SU) Fa4/2(P) Fa4/3(P) Fa4/4(P) Fa4/5(P) Cat6500# Cat6500#show etherchannel port-channel Channel-group listing: ----------------------- Group: 1 ---------- Port-channels in the group: ---------------------- Port-channel: Po1 ------------ Age of the Port-channel = 01d:07h:35m:28s Logical slot/port = 14/1 Number of ports = 4 GC = 0x00010001 HotStandBy port = null Port state = Port-channel Ag-Inuse Ports in the Port-channel: Index Load Port EC state ------+------+------+------------ 0 11 Fa4/2 on 1 22 Fa4/3 on 2 44 Fa4/4 on 3 88 Fa4/5 on Time since last port bundled: 01d:06h:56m:08s Fa4/5 Time since last port UN-bundled: 01d:06h:57m:15s Fa4/5 Cat6500#show interfaces port-channel 1 switchport Name: Po1 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: isl Operational Trunking Encapsulation: isl Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative private-vlan host-association: none Administrative private-vlan mapping: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Cat6500#
使用本節內容,確認您的組態是否正常運作。
輸出直譯器工具 (僅供已註冊客戶使用)(OIT)支援某些show命令。使用OIT檢視show命令輸出的分析。
Cat2950#show cdp neighbors Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater Device ID Local Intrfce Holdtme Capability Platform Port ID Cat2950 Fas 0/4 120 R S I Catalyst 6Fas 4/4 Cat2950 Fas 0/5 120 R S I Catalyst 6Fas 4/5 Cat2950 Fas 0/3 120 R S I Catalyst 6Fas 4/3 Cat2950 Fas 0/2 120 R S I Catalyst 6Fas 4/2 Cat2950# Cat2950#show etherchannel port-channel Channel-group listing: ----------------------- Group: 1 ---------- Port-channels in the group: ---------------------- Port-channel: Po1 ------------ Age of the Port-channel = 01d:08h:27m:08s Logical slot/port = 1/0 Number of ports = 4 GC = 0x00010001 HotStandBy port = null Port state = Port-channel Ag-Inuse Ports in the Port-channel: Index Load Port EC state ------+------+------+------------ 0 00 Fa0/2 desirable-SL 0 00 Fa0/3 desirable-SL 0 00 Fa0/4 desirable-SL 0 00 Fa0/5 desirable-SL Time since last port bundled: 00d:00h:07m:17s Fa0/5 Time since last port UN-bundled: 01d:08h:10m:06s Fa0/5 Cat2950# Cat2950#show etherchannel load-balance Source MAC address Cat2950# Cat2950#show interfaces port-channel 1 switchport Name: Po1 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Protected: false Voice VLAN: none (Inactive) Appliance trust: none Cat2950#
Cat6500#show etherchannel port-channel Channel-group listing: ----------------------- Group: 1 ---------- Port-channels in the group: ---------------------- Port-channel: Po1 ------------ Age of the Port-channel = 01d:08h:25m:07s Logical slot/port = 14/1 Number of ports = 4 GC = 0x00010001 HotStandBy port = null Port state = Port-channel Ag-Inuse Ports in the Port-channel: Index Load Port EC state ------+------+------+------------ 1 11 Fa4/2 desirable-SL 3 22 Fa4/3 desirable-SL 0 44 Fa4/4 desirable-SL 2 88 Fa4/5 desirable-SL Time since last port bundled: 00d:00h:09m:53s Fa4/3 Time since last port UN-bundled: 00d:00h:09m:56s Fa4/5 Cat6500#
使用本節內容,對組態進行疑難排解。
可能導致問題的原因之一是:
兩台交換器之間所連線的連線埠上存在本徵VLAN組態不相符的情況。
檢驗兩台交換機上的本徵VLAN配置。在CatOS交換器上發出show trunk命令,以便檢視本地VLAN設定。在XL交換器上發出show interface interface_id switchport 命令,以便檢視本地VLAN設定。如果兩台交換器之間的本徵VLAN不匹配,請使用相同的本徵VLAN配置交換器。發出switchport trunk native vlan 介面組態指令,變更XL交換器上的原生VLAN。發出set vlan 指令,變更CatOS交換器上的原生VLAN。
XL交換機不支援DTP幀。
CatOS交換機通過中繼鏈路傳送DTP幀,但XL交換機不支援DTP幀。XL交換器不支援DTP。為了避免此問題,請將CatOS交換機埠狀態設定為no negotiate。發出set trunk mod/port nonegotiate dot1q 命令,將dot1q中繼模式的中繼模式設定為nonegotiate。
XL交換器上存在封裝不相符。
在XL交換機上,檢驗中繼封裝是否設定為dot1q。發出show interface interface_id switchport 命令以檢視目前設定。發出switchport trunk encapsulation dot1q 介面組態命令,將封裝變更為dot1q。
早期版本的CatOS不支援dot1q中繼。
交換機中使用的CatOS早期版本不支援dot1q中繼。將交換機的CatOS升級到同時支援dot1q中繼和ISL中繼的更高版本。