Figure 8-4: Border Router, Internal router Networks and subnets Subnet 192.168.2.X Borde Subnet Router Internal 192.168.1X ISP Network Router Corporate 60xXX Network 192168xX Subnet 192.168.3.x Internal routers connect different subnets in a network n this case the three subnets are boxed in red 192168.1.X,192.1682x,and192.168.3X 8-16
8-16 Figure 8-4: Border Router, Internal Router, Networks, and Subnets Figure 8-4: Border Router, Internal Router, Netw orks, and Subnets ISP Network 60.x.x.x Subnet 192.168.2.x Subnet 192.168.3.x Subnet Internal 192.168.1.x Router Border Router Corporate Network 192.168.x.x Internal routers connect different subnets in a network. In this case, the three subnets are boxed in red: 192.168.1.x, 192.168.2.x, and 192.168.3.x
Figure 8-5: Multiprotocol Routing Site B Site A uniX Ethernet Old IPX SNA Edge Mainframe Server LAn 1 NetWare SPX Router Z Server TCP/ Multiprotocol Router TCP/ The Internet Ethenet Ethernet LAN 2 Lan 3 P Real routers must handle multiple WW Server nternet and transport layer architectures TCP/IP IPX/SPX SNA etc We will only look at TCP/P routing 8-17
8-17 Figure 8-5: Multiprotocol Routing Multiprotocol Router X TCP/ IP TCP/ IP IPX/ SPX SNA WWW Server Edge Router Z Site A Site B Mainframe Internal Router Y Ethernet LAN 1 Ethernet LAN 2 Ethernet Lan 3 The Internet Old NetWare Server UNIX Server Figure 8-5: Multiprotocol Routing Real routers must handle multiple internet and transport layer architectures— TCP/IP, IPX/SPX, SNA, etc. We will only look at TCP/IP routing
Page 351 Test Your understanding 2
• Page 351 • Test Your understanding • 2
I Figure 8-6: Ethernet Switching versus IP Routing Ethernet Switching Switch ,,,,,,,, Destination address is E5-BB-47-21-D3-56 Ethernet switches are arranged in a hierarchy Mitch 2 So there is only one possible path between hosts witch 3 So only one row can match an Ethernet address Finding this row is very simple and fast So Ethernet switching Is inexpensive per frame handled. Switch 1 OIL ElaTIon Switch A144-D5-1F-AA4C B2CD135B-E4-65 5c32D-553B-A94F B6-9 E5BB47-21-356 A144-D5-1F-AA4C Switch 1, Port 2 B2-CD-13-5B-E4-65 Switch 1. Port 7 One correct row 8-19
8-19 Figure 8-6: Ethernet Switching Versus IP Routing A1-44-D5-1F-AA-4C Switch 1, Port 2 B2-CD-13-5B-E4-65 Switch 1, Port 7 Port 7 on Switch 2 to Port 4 on Switch 3 Port 5 on Switch 1 to Port 3 on Switch 2 Switch 2 Switch 1 Switching Table Switch 1 Port Station 2 A1-44-D5-1F-AA-4C 7 B2-CD-13-5B-E4-65 5 C3-2D-55-3B-A9-4F 5 D4-47-55-C4-B6-9F 5 E5-BB-47-21-D3-56 Ethernet Switching Destination address is E5-BB-47-21-D3-56. Ethernet switches are arranged in a hierarchy. So there is only one possible path between hosts. So only one row can match an Ethernet address. Finding this row is very simple and fast. So Ethernet switching is inexpensive per frame handled. One Correct Row
Figure 8-6: Ethernet Switching Versus IP Routing Routing Interface IP Routing Router B Packet to 60. 3.47. 129 Interface 2 Routing Table for Router A Network 60.xxX Matches IP Address Next-Hop Route Range Metric Router Router c _1603Xx Network 2128.171x 360.347X 9286 BBCB 60.3XX 10.5.3X Host 5128.171.17.X2 Local 60.347.X Because of multiple alternative routes in router meshes routers may have several rows that match an IP address Routers must find all matches and then select the best one This is slow and therefore expensive compared to switching 8-20
8-20 Figure 8-6: Ethernet Switching Versus IP Routing Network 60.x.x.x Packet to 60.3.47.129 Router B Router C Interface 1 Interface 2 Network 60.x.x.x IP Routing Network 60.3.x.x Route 1 2 3 4 5 6 IP Address Range 60.3.x.x 128.171.x.x 60.3.47.x 10.5.3.x 128.171.17.x 10.4.3.x Metric 9 2 8 6 2 2 Router A Routing Table for Router A Host 60.3.45.129 Next-Hop Router B B C B Local C Routing Matches Host 60.3.47.x Because of multiple alternative routes in router meshes, routers may have several rows that match an IP address. Routers must find All matches and then select the BEST ONE. This is slow and therefore expensive compared to switching