Some endpoints will boot into iPXE while others fail to boot into iPXE and get error: pxe-e21
There is no ACK from DHCP message after the offer message as seen here:
Also the you will see in the wireshark this capture output:
Magic cookie: DHCP    Option: (53) DHCP Message Type (Discover)        Length: 1        DHCP: Discover (1)    Option: (57) Maximum DHCP Message Size        Length: 2        Maximum DHCP Message Size: 1472    Option: (93) Client System Architecture        Length: 2        Client System Architecture: EFI x64 (7)    Option: (94) Client Network Device Interface        Length: 3        Major Version: 3        Minor Version: 10    Option: (60) Vendor class identifier        Length: 32        Vendor class identifier: PXEClient:Arch:00007:UNDI:003010    Option: (77) User Class Information        Length: 4        User Class Data (Text): iPXE            [Expert Info (Note/Protocol): Non standard compliant option data]                [Non standard compliant option data]                [Severity level: Note]                [Group: Protocol]    Option: (55) Parameter Request List        Length: 23        Parameter Request List Item: (1) Subnet Mask        Parameter Request List Item: (3) Router        Parameter Request List Item: (6) Domain Name Server        Parameter Request List Item: (7) Log Server        Parameter Request List Item: (12) Host Name        Parameter Request List Item: (15) Domain Name        Parameter Request List Item: (17) Root Path        Parameter Request List Item: (26) Interface MTU        Parameter Request List Item: (43) Vendor-Specific Information        Parameter Request List Item: (60) Vendor class identifier        Parameter Request List Item: (66) TFTP Server Name        Parameter Request List Item: (67) Bootfile name        Parameter Request List Item: (119) Domain Search        Parameter Request List Item: (128) DOCSIS full security server IP [TODO]        Parameter Request List Item: (129) PXE - undefined (vendor specific)        Parameter Request List Item: (130) PXE - undefined (vendor specific)        Parameter Request List Item: (131) PXE - undefined (vendor specific)        Parameter Request List Item: (132) PXE - undefined (vendor specific)        Parameter Request List Item: (133) PXE - undefined (vendor specific)        Parameter Request List Item: (134) PXE - undefined (vendor specific)        Parameter Request List Item: (135) PXE - undefined (vendor specific)        Parameter Request List Item: (175) Etherboot        Parameter Request List Item: (203) Unassigned
GSS 3.3 RU10 and lower
Issues have been seen where NIC firmware does not support iPXE 1.0.0.
This issue can be seen in wireshark where the DHCP does not give an ACK message.
Upgrade to GSS RU11.