Chapter 17
| General IP Routing
IP Routing and Switching
– 636 –
Figure 422: Virtual Interfaces and Layer 3 Routing
IP Routing and Switching
IP Switching (or packet forwarding) encompasses tasks required to forward packets
for both Layer 2 and Layer 3, as well as traditional routing. These functions include:
◆
Layer 2 forwarding (switching) based on the Layer 2 destination MAC address
◆
Layer 3 forwarding (routing):
■
Based on the Layer 3 destination address
■
Replacing destination/source MAC addresses for each hop
■
Incrementing the hop count
■
Decrementing the time-to-live
■
Verifying and recalculating the Layer 3 checksum
If the destination node is on the same subnetwork as the source network, then the
packet can be transmitted directly without the help of a router. However, if the MAC
address is not yet known to the switch, an Address Resolution Protocol (ARP)
packet with the destination IP address is broadcast to get the destination MAC
address from the destination node. The IP packet can then be sent directly with the
destination MAC address.
VLA
N
1
VLA
N
2
I
nter
-
subnet traff
i
c (Layer 3 sw
i
tch
i
ng)
Rout
i
ng
Unt
Untagged
Unt
Untagged
Tagged or Untagged
Tagged or Untagged
Tagged or Untagged
Tagged or Untagged
I
ntra
-
subnet traff
i
c (Layer 2 sw
i
tch
i
ng)
Содержание GTL-2881
Страница 30: ...Figures 30 Figure 450 Showing RIP Peer Information 669 Figure 451 Resetting RIP Statistics 670 ...
Страница 34: ...Section I Getting Started 34 ...
Страница 48: ...Section II Web Configuration 48 Unicast Routing on page 651 ...
Страница 151: ...Chapter 4 Interface Configuration VLAN Trunking 151 Figure 69 Configuring VLAN Trunking ...
Страница 152: ...Chapter 4 Interface Configuration VLAN Trunking 152 ...
Страница 229: ...Chapter 8 Congestion Control Automatic Traffic Control 229 Figure 135 Configuring ATC Interface Attributes ...
Страница 230: ...Chapter 8 Congestion Control Automatic Traffic Control 230 ...
Страница 596: ...Chapter 14 Multicast Filtering Multicast VLAN Registration for IPv6 596 ...
Страница 620: ...Chapter 15 IP Configuration Setting the Switch s IP Address IP Version 6 620 ...
Страница 670: ...Chapter 18 Unicast Routing Configuring the Routing Information Protocol 670 Figure 451 Resetting RIP Statistics ...
Страница 672: ...Section III Appendices 672 ...
Страница 678: ...Appendix A Software Specifications Management Information Bases 678 ...
Страница 688: ...Appendix C License Statement GPL Code Statement Notification of Compliance 688 ...
Страница 696: ...Glossary 696 ...
Страница 706: ...GTL 2881 GTL 2882 E112016 ST R01 ...