Posted on June 18, 2021 7:47 am
 |  Asked by Jonas Pfefferle
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We have a DCS-7150S-24-F were one port is connected to a DHCP server which distributes IPv6 prefixes via DHCP-PD.

Can I configure the switch to use ipv6 RA to distribute the prefixes received via this DHCP server on a particular VLAN?

Do I need to use dhcp relay to the virtual VLAN interface for this?

Is it possible to announce a smaller prefix e.g. the DHCP server provides a /32 and the switch distributes /64 prefixes. Such that we could serve multiple VLANs with a single prefix from DHCP.


Posted by Kenneth Finnegan
Answered on June 18, 2021 8:31 pm

Howdy Jonas,

Newer versions of EOS support DHCPv6-PD for DHCP relay, where it can act as the DHCP relay for PD requests and install the routes for the delegated prefixes, but I don't believe any version of EOS currently supports acting as a DHCP-PD client or server, so it can't allocate prefixes for itself.

I also believe that what PD support EOS has isn't included in the 4.23 train, so wouldn't be supported on the 7150S.

Posted by Jonas Pfefferle
Answered on June 22, 2021 7:43 am

Hi Kenneth

Thank you! From the documentation it sounded like that distributing smaller prefixes is not possible so thanks for "confirming".

I have not checked on the actual hardware but according to 7150S supports DHCP relay and DHCP-PD.


Posted by Jonas Pfefferle
Answered on July 7, 2021 7:59 pm

Since I did not find any solution for the above problem I wrote a small EOS python extension that allows to send DHCP-PD request on an interface and assign prefixes for RA to other interfaces. More details here:

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