H3C Technologies H3C S10500 Series Switches - Manual (Page 13)

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3. The source edge device forwards the encapsulated packet out of the EVI link to the destination
edge device across the IP transport network.
4. The destination edge device removes the headers of the original Ethernet frame, looks up the
destination MAC address in the MAC address table, and sends the frame out of the matching
outgoing interface.
Figure 5 Layer 2 forwarding between sites
Multicast flow
The EVI implementation of the device does not support multicast forwarding between sites based on the
multicast forwarding table.
By default, the device does not forward multicast traffic to remote sites.
To forward traffic destined for a multicast MAC address to remote sites, you must enable selective flood
for the address.
Flooding flow
An edge device handles flooding by frame type, as follows:
• Broadcast frame—Floods the frame to all interfaces in the VLAN where the frame has been
received, including internal interfaces and EVI-Link interfaces.
• Multicast or destination-unknown unicast frame—Floods the frame to all internal interfaces in the
VLAN where the frame has been received. The edge device typically does not forward
destination-unknown frames to other sites. If a site-to-site flooding is desirable for a special MAC
address, use the selective flood feature (see "
Selective flood ").
To flood a frame to remote sites, an EVI edge device must replicate the frame, encapsulate each replica
in one unicast frame for each destination site, and send the unicast frames to the remote edge devices.
Transport network
EVI
Site 1
EVI
Site 2
MAC1
EVI MAC Table
VLAN MAC Interface
200 MAC1
200 MAC3
200 MAC2
EVI-Link0
GE1/0/1
EVI-Link0
MAC Table
VLAN MAC Interface
200 MAC1 GE1/0/1
200 MAC3 EVI-Link0
200 MAC2 GE1/0/2
Host A
MAC2
Host B
MAC3
Host C
GE1/0/1 Switch A Switch B
a
b
c
d
e