通常,網橋在開放系統互聯(OSI)參考模型的資料鏈路層(第2層)上運行。網橋將根據傳入幀的媒體訪問控制(MAC)地址對其進行過濾、轉發或泛洪。
橋接是纜線資料機聯機時獲得的預設設定。
在橋接應用中,當運行Cisco IOS®軟體版本12.0.5T1及更高版本時,Cisco uBR900系列電纜接入路由器充當乙太網埠上最多254個裝置的透明網橋。早期版本的Cisco IOS軟體最多支援Cisco uBR900系列路由器的乙太網埠上的三台裝置。
此配置已在運行Cisco IOS軟體版本12.0(7)T的uBR904和運行Cisco IOS軟體版本12.1(2)T的Cisco uBR7223上測試。
如需文件慣例的詳細資訊,請參閱思科技術提示慣例。
本文件沒有特定先決條件。
本檔案中的資訊是根據以下軟體和硬體版本。
執行Cisco IOS軟體版本12.0(7)T的uBR904
執行Cisco IOS軟體版本12.1(2)T的Cisco uBR7223
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)。
uBR900 |
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Current configuration: ! ! No configuration change since last restart !version 12.0 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Router ! ! ! ! ! ! clock timezone - 0 ip subnet-zero no ip routing !--- Router is operating in bridging mode. ! ! ! ! ! interface Ethernet0 ip address 10.1.1.26 255.255.255.0 no ip directed-broadcast no ip route-cache bridge-group 59 bridge-group 59 spanning-disabled ! interface cable-modem0 ip address negotiated no ip directed-broadcast no ip route-cache cable-modem downstream saved channel 453000000 28 1 cable-modem mac-timer t2 60000 bridge-group 59 bridge-group 59 spanning-disabled ! ip default-gateway 10.1.1.10 ip classless no ip http server ! ! line con 0 transport input none line vty 0 4 ! end Router# |
註:上述配置是在開啟電纜數據機電源並進入聯機狀態後獲得的。自出廠預設設定以來沒有配置更改。另請注意,在舊版Cisco IOS中,纜線介面會顯示實際的IP位址,而不是「交涉的IP位址」。
uBR7200 |
Current configuration: ! ! Last configuration change at 16:55:41 UTC Mon Nov 20 2000 ! NVRAM config last updated at 16:55:12 UTC Mon Nov 20 2000 ! version 12.1 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname sniper ! boot system flash ubr7200-ik1s-mz_121-2_T.bin no logging buffered enable password cisco ! no cable qos permission create no cable qos permission update cable qos permission modems ! ! ! ip subnet-zero no ip domain-lookup ! no lane client flush ! ! ! ! interface FastEthernet0/0 no ip address shutdown half-duplex ! interface Ethernet1/0 ip address 172.17.110.139 255.255.255.224 ! interface Ethernet1/1 no ip address shutdown ! interface Ethernet1/2 no ip address shutdown ! interface Ethernet1/3 no ip address shutdown ! interface Ethernet1/4 no ip address shutdown ! interface Ethernet1/5 no ip address shutdown ! interface Ethernet1/6 no ip address shutdown ! interface Ethernet1/7 no ip address shutdown ! interface Cable2/0 ip address 10.10.1.1 255.255.255.0 secondary ip address 10.1.1.10 255.255.255.0 no keepalive cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 451250000 cable upstream 0 frequency 28000000 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown cable dhcp-giaddr policy cable helper-address 172.17.110.136 ! interface Cable3/0 no ip address no keepalive shutdown cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable upstream 0 shutdown cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown ! ip classless ip route 0.0.0.0 0.0.0.0 172.17.110.129 no ip http server ! ! line con 0 exec-timeout 0 0 transport input none line aux 0 line vty 0 exec-timeout 0 0 password cisco login line vty 1 4 password cisco login ! end |
注意: Output Interpreter Tool(僅供註冊客戶使用)支援某些show命令,這允許您檢視show命令輸出的分析。
要確保工作正常,請在Cisco uBR7200上輸入show cable modem命令。這將列出連線到此Cisco uBR7200的電纜數據機的狀態。下面是從上述uBR7200路由器獲得的輸出顯示:
sniper#sh cable modem Interface Prim Online Timing Rec QoS CPE IP address MAC address Sid State Offset Power Cable2/0/U0 11 online 2287 0.25 5 0 10.1.1.25 0050.7366.2223 Cable2/0/U0 12 online 2812 0.25 5 0 10.1.1.28 0001.9659.4415 Cable2/0/U0 13 online 2810 -0.50 5 0 10.1.1.20 0030.96f9.65d9 Cable2/0/U0 14 online 2290 0.50 5 0 10.1.1.26 0050.7366.2221 Cable2/0/U0 15 online 2292 0.25 5 0 10.1.1.30 0050.7366.1fb9 Cable2/0/U0 16 online 2815 0.00 5 0 10.1.1.27 0001.9659.4461
如果狀態未顯示「online」,我們需要對此進行故障排除。在Cisco uBR900上,您可以輸入debug cable-modem mac log verbose。有關故障排除的詳細資訊,請參閱uBR電纜數據機未聯機故障排除。