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Pero_G_159589's avatar
Pero_G_159589
Icon for Nimbostratus rankNimbostratus
Jun 03, 2014

DHCP relay function

Hello!

 

I have an issue with DHCP relay functionality on F5.

 

Let's assume clients should get IP address through F5 DHCP relay VS, and address space for those clients is subnet 10.78.105.0/24 on VLAN 105. One leg of F5 is placed into that VLAN 105, and the other leg is on segment where DHCP servers resides.

 

The issue is that all DHCP requests which F5 receives are relayed to server but with the source IPof that leg in clients VLAN, not in servers VLAN.

 

How to force that all requests from clients be relayed with source IP of the leg inside the servers segment?

 

Kind regards!

 

Pero

 

application delivery
BIG-IP Access Policy Manager (APM)
deployment
design
LTM
security
TMOS

2 Replies

  • What_Lies_Bene1's avatar
    What_Lies_Bene1
    Icon for Cirrostratus rankCirrostratus
    Jun 03, 2014

    What you are seeing is expected I believe; that's how DHCP relay works, the source/client IP address is preserved or, where it's 0.0.0.0, the F5's IP from the source/client VLAN is used.

     

    Obviously this simply means you need to ensure your DHCP servers have a route back to this IP/subnet via the F5.