Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.14.1.0 - Page 455
UDP Helper with No Con d Broadcast Addresses, Troubleshooting UDP Helper
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Figure 55. UDP Helper with Configured Broadcast Addresses UDP Helper with No Configured Broadcast Addresses The following describes UDP helper with no broadcast addresses configured. • If the incoming packet has a broadcast destination IP address, the unaltered packet is routed to all Layer 3 interfaces. • If the Incoming packet has a destination IP address that matches the subnet broadcast address of any interface, the unaltered packet is routed to the matching interfaces. Troubleshooting UDP Helper To display debugging information for troubleshooting, use the debug ip udp-helper command. Example of the debug ip udp-helper Command DellEMC(conf)# debug ip udp-helper 01:20:22: Pkt rcvd on Te 5/1 with IP DA (0xffffffff) will be sent on Te 5/2 Te 5/3 Vlan 3 01:44:54: Pkt rcvd on Te 7/1 is handed over for DHCP processing. When using the IP helper and UDP helper on the same interface, use the debug ip dhcp command. Example Output from the debug ip dhcp Command Packet 0.0.0.0:68 -> 255.255.255.255:67 TTL 128 2017-08-05 11:59:35 %RELAY-I-PACKET, BOOTP REQUEST (Unicast) received at interface 172.21.50.193 BOOTP Request, XID = 0x9265f901, secs = 0 hwaddr = 00:02:2D:8D:46:DC, giaddr = 0.0.0.0, hops = 2 2017-08-05 11:59:35 %RELAY-I-BOOTREQUEST, Forwarded BOOTREQUEST for 00:02:2D:8D:46:DC to 137.138.17.6 2017-08-05 11:59:36 %RELAY-I-PACKET, BOOTP REPLY (Unicast) received at interface 194.12.129.98 BOOTP Reply, XID = 0x9265f901, secs = 0 hwaddr = 00:02:2D:8D:46:DC, giaddr = 172.21.50.193, hops = 2 2017-08-05 11:59:36 %RELAY-I-BOOTREPLY, Forwarded BOOTREPLY for 00:02:2D:8D:46:DC to 128.141.128.90 Packet 0.0.0.0:68 -> 255.255.255.255:67 TTL 128 IPv4 Routing 455
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