DELL S50V User Manual

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IPv4 Addressing
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address of VLAN 101. If UDP helper is configured and the packet matches the specified UDP port, then 
the system changes the address to the configured IP broadcast address and floods the packet on VLAN 
101.
Packet 2 is sent from host on VLAN 101. It has a broadcast MAC address and a destination IP address of 
1.1.1.255. In this case, it is flooded on VLAN 101 in its original condition as the forwarding process is 
Layer 2.
Figure 21-15.  UDP helper with Subnet Broadcast Addresses
UDP Helper with Configured Broadcast Addresses
Incoming packets with a destination IP address matching the configured broadcast address of any interface 
are forwarded to the matching interfaces.
VLAN 100 and 101. If UDP helper is enabled and the UDP port number matches, the packet is flooded on 
both VLANs with an unchanged destination address.
Packet 2 is sent from a host on VLAN 101. It has broadcast MAC address and a destination IP address that 
matches the configured broadcast address on VLAN 101. In this case, Packet 2 is flooded on VLAN 101 
with the destination address unchanged because the forwarding process is Layer 2. If UDP helper is 
enabled, the packet is flooded on VLAN 100 as well.
Figure 21-16.  UDP Helper with Configured Broadcast Addresses
    TLV 1
Chassis ID
Preamble
Start Frame
  Delimiter
 Destination MAC
(01:80:C2:00:00:0E)
     Source MAC
Ethernet Type
    (0x88CC)
LLDPDU
Padding
FCS
 TLV 2
Port ID
         TLV 3
Port Description
       TLV 4
System Name
            TLV 5
System Description
            TLV 6
System Capabilities
            TLV 7
Management Addr
         TLV 0
End of LLDPDU
                TLV 127
Organizationally Specific
Packet 1
Destination Address:
1.1.255.255
1/1
Ingress interface
IP Address: 2.1.1.1/24
UDP helper enabled
1/2
1/3
VLAN 100
IP address: 1.1.0.1/24
Subnet broadcast address: 1.1.0.255
Configured broadcast address: 
1.1.255.255
Hosts on VLAN 100: 1.1.0.2, 1.1.0.3, 1.1.0.4
VLAN 101
IP address: 1.11.1/24
Subnet broadcast address: 1.1.1.255
Configured broadcast address: 
1.1.255.255
Hosts on VLAN 100: 1.1.1.2, 1.1.1.3, 1.1.1.4
fnC0048mp
Packet 2
Switched Packet
Destination Address:
1.1.255.255