IP Routing Features

 

 

 

 

 

 

UDP Broadcast Forwarding

Table 7-5.

Example of a UDP Packet-Forwarding Environment

 

 

 

 

 

 

 

Interface

IP

 

Subnet

Forwarding

UDP

Notes

 

Address

 

Mask

Address

Port

 

VLAN 1

15.75.10.1

255.255.255.0

15.75.11.43

1188

Unicast address for forwarding inbound UDP packets with

 

 

 

 

 

 

UDP port 1188 to a specific device on VLAN 2.

 

 

 

 

15.75.11.255

1812

Broadcast address for forwarding inbound UDP packets

 

 

 

 

 

 

with UDP port 1812 to any device in the 15.75.11.0 network.

 

 

 

 

15.75.12.255

1813

Broadcast address for forwarding inbound UDP packets

 

 

 

 

 

 

with UDP port 1813 to any device in the 15.75.12.0 network.

VLAN 2

15.75.11.1

255.255.255.0

None

N/A

Destination VLAN for UDP 1188 broadcasts from clients on

 

 

 

 

 

 

VLAN 1. The device identified in the unicast forwarding

 

 

 

 

 

 

address configured in VLAN 1 must be on this VLAN.

 

 

 

 

 

 

Also the destination VLAN for UDP 1812 from clients on

 

 

 

 

 

 

VLAN 1.

VLAN 3

15.75.12.1

255.255.255.0

None

N/A

Destination VLAN for UDP 1813 broadcasts from clients on

 

 

 

 

 

 

VLAN 1.

 

 

 

 

 

 

 

 

 

 

 

N o t e

 

 

If an IP server or subnet entry is invalid, a switch will not try to forward UDP

packets to the configured device or subnet address.

Subnet Masking for UDP Forwarding Addresses

The subnet mask for a UDP forwarding address is the same as the mask applied to the subnet on which the inbound UDP broadcast packet is received. To forward inbound UDP broadcast packets as limited broadcasts to other subnets, use the broadcast address that covers the subnet you want to reach. For example, if VLAN 1 has an IP address of 15.75.10.1/24 (15.75.10.1 255.255.255.0), then you can configure the following unicast and limited broadcast addresses for UDP packet forwarding to subnet 15.75.11.0:

Forwarding Destination Type

IP Address

 

 

UDP Unicast to a Single Device in the 15.75.11.0 Subnet

15.75.11.X

UDP Broadcast to Subnet 15.75.11.0

15.75.11.255

 

 

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