Edge-Core ECS4620-28F - Figure 440: Virtual Interfaces and Layer 3 Routing; IP Routing and Switching

Chapter 17 | General IP Routing
IP Routing and Switching
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Each VLAN represents a virtual interface to Layer 3. You just need to provide the
network address for each virtual interface, and the traffic between different
subnetworks will be routed by Layer 3 switching.
Figure 440: 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):
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Based on the Layer 3 destination address
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Replacing destination/source MAC addresses for each hop
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Incrementing the hop count
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Decrementing the time-to-live
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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
VLAN 1
VLAN 2
Inter-subnet traffic (Layer 3 switching)
Routing
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Tagged or Untagged Tagged or Untagged
Tagged or Untagged Tagged or Untagged
Intra-subnet traffic (Layer 2 switching)