Internet address is 1.1.0.1/24
IP UDP-Broadcast address is 1.1.255.255
MTU 1554 bytes, IP MTU 1500 bytes
LineSpeed auto
ARP type: ARPA, ARP Timeout 04:00:00
Last clearing of "show interface" counters 00:07:44
Queueing strategy: fifo
Input Statistics:
0 packets, 0 bytes
Time since last interface status change: 00:07:44
Configurations Using UDP Helper
When you enable UDP helper and the destination IP address of an incoming packet is a broadcast address, Dell Networking OS suppresses
the destination address of the packet.
The following sections describe various configurations that employ UDP helper to direct broadcasts.
•
UDP Helper with Broadcast-All Addresses
•
UDP Helper with Subnet Broadcast Addresses
•
UDP Helper with Configured Broadcast Addresses
•
UDP Helper with No Configured Broadcast Addresses
UDP Helper with Broadcast-All Addresses
When the destination IP address of an incoming packet is the IP broadcast address, Dell Networking OS rewrites the address to match the
configured broadcast address.
In the following illustration:
1
Packet 1 is dropped at ingress if you did not configure UDP helper address.
2
If you enable UDP helper (using the
ip udp-helper udp-port
command), and the UDP destination port of the packet matches
the UDP port configured, the system changes the destination address to the configured broadcast 1.1.255.255 and routes the packet
to VLANs 100 and 101. If you do not configure an IP broadcast address (using the
ip udp-broadcast-address
command) on
VLANs 100 or 101, the packet is forwarded using the original destination IP address 255.255.255.255.
Packet 2, sent from a host on VLAN 101 has a broadcast MAC address and IP address. In this case:
1
It is flooded on VLAN 101 without changing the destination address because the forwarding process is Layer 2.
2
If you enabled UDP helper, the system changes the destination IP address to the configured broadcast address 1.1.255.255 and
forwards the packet to VLAN 100.
3
Packet 2 is also forwarded to the ingress interface with an unchanged destination address because it does not have broadcast
address configured.
IPv4 Routing
447
Содержание S4048T-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 11 2 1 ...
Страница 148: ...Figure 10 BFD Three Way Handshake State Changes 148 Bidirectional Forwarding Detection BFD ...
Страница 251: ...Dell Control Plane Policing CoPP 251 ...
Страница 363: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 363 ...
Страница 511: ...Figure 64 Inspecting the LAG Configuration Link Aggregation Control Protocol LACP 511 ...
Страница 512: ...Figure 65 Inspecting Configuration of LAG 10 on ALPHA 512 Link Aggregation Control Protocol LACP ...
Страница 515: ...Figure 67 Inspecting a LAG Port on BRAVO Using the show interface Command Link Aggregation Control Protocol LACP 515 ...
Страница 516: ...Figure 68 Inspecting LAG 10 Using the show interfaces port channel Command 516 Link Aggregation Control Protocol LACP ...
Страница 558: ...Figure 84 Configuring Interfaces for MSDP 558 Multicast Source Discovery Protocol MSDP ...
Страница 559: ...Figure 85 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 559 ...
Страница 560: ...Figure 86 Configuring PIM in Multiple Routing Domains 560 Multicast Source Discovery Protocol MSDP ...
Страница 564: ...Figure 88 MSDP Default Peer Scenario 2 564 Multicast Source Discovery Protocol MSDP ...
Страница 565: ...Figure 89 MSDP Default Peer Scenario 3 Multicast Source Discovery Protocol MSDP 565 ...
Страница 729: ...protocol spanning tree pvst no disable vlan 300 bridge priority 4096 Per VLAN Spanning Tree Plus PVST 729 ...
Страница 841: ...Figure 115 Single and Double Tag TPID Match Service Provider Bridging 841 ...
Страница 842: ...Figure 116 Single and Double Tag First byte TPID Match 842 Service Provider Bridging ...