H3C Technologies H3C S12500 Series Switches - Manual (Page 215)

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The following process describes how a packet is transmitted from Host A1 to Host B2:
• Host A1 sends out the packet.
• Layer 2 Switch A adds VLAN 11 to the packet and forwards the single-tagged packet to Layer 3
Switch C.
• Layer 3 Switch C receives the packet on GigabitEthernet 3/0/1, adds VLAN 100 to the packet as
the outer VLAN tag, and forwards the double-tagged packet to VLAN-interface 100, which is the
gateway of Host A1.
• VLAN-interface 100 removes the two layers of VLAN tags of the packet and forwards the packet to
the gateway of Host B2, which is VLAN-interface 200.
• VLAN-interface 200 searches the ARP table for the VLAN ID (VLAN 12) mapped to Host B2, adds
outer VLAN tag 200 and inner VLAN tag 12 to the packet, and forwards the double-tagged packet
to the access port GigabitEthernet 3/0/2.
• Port GigabitEthernet 3/0/2 removes the default VLAN tag (VLAN 200) of the packet and forwards
the packet tagged with VLAN 12 to Layer 2 Switch B.
• Layer 2 Switch B forwards the packet to Host B2 in VLAN 12.
Configuration procedure
1. Configure hosts:
{
Configure Host A1's IP address as 1.1.1.1/24, Host B1's IP address as 1.1.1.2/24, Host C1's IP
address as 1.1.1.3/24, and their gateway IP address as 1.1.1.11/24.
{
Configure Host A2's IP address as 2.1.1.1/24, Host B2's IP address as 2.1.1.2/24, Host C2's IP
address as 2.1.1.3/24, and their gateway IP address as 2.1.1.11/24.
2. Configure Layer 2 Switch A:
# Assign GigabitEthernet 1/0/1 to VLAN 11.
<L2_SwitchA> system-view
[L2_SwitchA] vlan 11
[L2_SwitchA-vlan11] port GigabitEthernet 1/0/1
[L2_SwitchA-vlan11] quit
# Assign GigabitEthernet 1/0/2 to VLAN 12.
[L2_SwitchA] vlan 12
[L2_SwitchA-vlan12] port GigabitEthernet 1/0/2
[L2_SwitchA-vlan12] quit
# Assign GigabitEthernet 1/0/3 to VLAN 13.
[L2_SwitchA] vlan 13
[L2_SwitchA-vlan13] port GigabitEthernet 1/0/3
[L2_SwitchA-vlan13] quit
# Configure GigabitEthernet 1/0/7 as a trunk port and assign the port to VLANs 11 through 13.
[L2_SwitchA] interface GigabitEthernet 1/0/7
[L2_SwitchA-GigabitEthernet1/0/7] port link-type trunk
[L2_SwitchA-GigabitEthernet1/0/7] port trunk permit vlan 11 to 13
3. Configure Layer 2 Switch B in the same way Layer 2 Switch A is configured.
4. Configure Layer 3 Switch C:
# Assign GigabitEthernet 3/0/1 to VLAN 100 and enable QinQ on the interface to tag the
received packets with the PVID.
[L3_SwitchC] vlan 100