Bridge Overview
293
Figure 106
Filter (not forward)
■
Suppose that Workstation A sends an Ethernet frame to Workstation C, and
the bridge does not find the correlation between the MAC address of
Workstation C and the port in the bridging address table, what will the bridge
do? The bridge will forward this frame destined to an unknown MAC address
to all ports except the one on which it is received. In this case, the bridge
actually plays the role of a hub to make sure the continuous information
transmission, as shown in the following figure:
Figure 107
No matched MAC address is found in the bridging table
Eliminating loop
As shown in the following figure, both bridges X and Y are connected with
Ethernet segment 1. Once detecting a broadcasting frame, both bridges will send
it to all ports except the source port on which the frame is detected. That is, both
bridges X and Y will forward this broadcast frame.
No forwarding
Bridge
Ethernet segment 1
Bridge port 1
Bridge port 2
Ethernet segment 2
00e0.fcaa.aaaa 00e0.fcbb.bbbb
Source address Destination address
Bridging table
MAC address
00e0.fcbb. bbbb
00e0.fccc . cccc
00e0.fcdd.dddd
00e0.fcaa.aaaa
Port
1
1
2
2
Workstation A
Workstation B
Workstation C
Workstation D
00e0.fcaa.aaaa
00e0.fcbb.bbbb
00e0.fcdd.dddd
Bridge
Ethernet segment 1
Bridge port 1
Bridge port 2
00e0.fccc.cccc
00e0.fcdd.dddd
Ethernet segment 2
00e0.fcaa.aaaa
00e0.fcbb.bbbb
00e0.fcaa.aaaa 00e0.fccc.cccc
Source address Destination address
Bridging table
MAC address
00e0.fcaa.aaaa
Port
1
1
00e0.fcbb.bbbb
Содержание 3036
Страница 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299 ...
Страница 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721 ...
Страница 6: ...2 ABOUT THIS GUIDE ...
Страница 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface ...
Страница 8: ...4 ...
Страница 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION ...
Страница 34: ...30 ...
Страница 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT ...
Страница 88: ...84 CHAPTER 5 CONFIGURING NETWORK MANAGEMENT RouterA interface ethernet 0 RouterA Ethernet0 rmon promiscuous ...
Страница 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS ...
Страница 110: ...106 ...
Страница 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW ...
Страница 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE ...
Страница 168: ...164 ...
Страница 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT ...
Страница 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1 ...
Страница 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25 ...
Страница 292: ...288 CHAPTER 18 CONFIGURING HDLC Enable HDLC packet debugging debugging hdlc packet interface type number ...
Страница 320: ...316 ...
Страница 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS ...
Страница 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION ...
Страница 374: ...370 CHAPTER 23 CONFIGURING IP COUNT ...
Страница 406: ...402 CHAPTER 25 CONFIGURING DLSW ...
Страница 408: ...404 ...
Страница 452: ...448 CHAPTER 29 CONFIGURING OSPF ...
Страница 482: ...478 CHAPTER 30 CONFIGURING BGP ...
Страница 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY ...
Страница 502: ...498 ...
Страница 508: ...504 CHAPTER 33 IP MULTICAST ...
Страница 514: ...510 CHAPTER 34 CONFIGURING IGMP ...
Страница 526: ...522 CHAPTER 36 CONFIGURING PIM SM ...
Страница 528: ...524 ...
Страница 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY ...
Страница 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL ...
Страница 590: ...586 CHAPTER 40 CONFIGURING IPSEC ...
Страница 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE ...
Страница 600: ...596 ...
Страница 638: ...634 CHAPTER 43 CONFIGURING L2TP ...
Страница 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
Страница 650: ...646 ...
Страница 666: ...662 ...
Страница 670: ...666 CHAPTER 47 QOS OVERVIEW ...
Страница 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT ...
Страница 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE ...
Страница 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem ...
Страница 708: ...704 ...
Страница 762: ...758 CHAPTER 52 CONFIGURING MODEM ...