Reset Search
 

 

Article

S-Series: What port does IP-Helper use for relaying DHCP requests

« Go Back

Information

 
TitleS-Series: What port does IP-Helper use for relaying DHCP requests
Question
What port does IP-Helper use for relaying DHCP requests
Environment
  • S-Series
  • Firmware 8.42.xx
  • Firmware 8.62.xx
  • DHCP
  • Ip-helper
Answer

DHCP messages from a client to a server are sent to the 'DHCP server' port (67), and DHCP messages from a server to a client are sent to the 'DHCP client' port (68).
 
If the S is used as a Relay agent: 

  • Client sends DHCP discover and Request messages with Source port 68 and Dest port 67 
  • Relay agent forwards using Source port 68 / Destination port 67 to the DHCP server
  • Relay agent converts server response  back to Src67 / Dest68 to the client.

 

Additional notes
See this article for details of how to change the source port used by dhcp relay ( firmware dependent )
S-Series: Need to change the ip helper to send DHCP discover and request using SRC port 67 instead of 68

Feedback

 

Was this article helpful?


   

Feedback

Please tell us how we can make this article more useful.

Characters Remaining: 255