Bug 2062295

Summary: [RFE] OVN: DHCP server support for chainloading iPXE with IPv6
Product: Red Hat Enterprise Linux Fast Datapath Reporter: Lucas Alvares Gomes <lmartins>
Component: OVNAssignee: lorenzo bianconi <lorenzo.bianconi>
Status: MODIFIED --- QA Contact: ying xu <yinxu>
Severity: high Docs Contact:
Priority: high    
Version: RHEL 8.0CC: ctrautma, jiji, jkreger, mmichels
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Description Lucas Alvares Gomes 2022-03-09 13:48:57 UTC 
The RFE [0] implemented iPXE chainloading support for IPv4. In order to complete the work we also need to implement it for IPv6.

There are some differences in how OVN DHCP should behave for these two versions:

1) For IPv4, OVN DHCP will look for option 175. If set it will return "bootfile_name" if unset it will return "bootfile_name_alt" (see RFE [0] for more details)

2) For IPv6, instead of looking for option 175 OVN DHCP should look at the "user class" field from the DHCP request and see if it's set to "iPXE" [1][2].

[0] https://bugzilla.redhat.com/show_bug.cgi?id=1765506
[1] https://github.com/openstack/neutron/blob/a7010e9c4e844940ef33aae3309ca4e323bef78e/neutron/agent/linux/dhcp.py#L393-L394
[2] https://datatracker.ietf.org/doc/html/rfc3315#section-22.15
Comment 1 lorenzo bianconi 2023-05-10 08:17:57 UTC 
upstream feature: https://patchwork.ozlabs.org/project/ovn/cover/cover.1683299858.git.lorenzo.bianconi@redhat.com/