Comment 3 for bug 1990028

More verbose tcpdump data:
```
[tripleo-admin@controller-0 ~]$ sudo tcpdump -vvvv -i vlan50 port 67 or port 68 or port 69 or port 4011
dropped privs to tcpdump
tcpdump: listening on vlan50, link-type EN10MB (Ethernet), snapshot length 262144 bytes
10:41:39.857818 IP (tos 0x0, ttl 64, id 51868, offset 0, flags [none], proto UDP (17), length 375)
    0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:25:90:d5:bf:28 (oui Unknown), length 347, xid 0x4371427b, Flags [Broadcast] (0x8000)
          Client-Ethernet-Address 00:25:90:d5:bf:28 (oui Unknown)
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Discover
            MSZ (57), length 2: 1464
            Parameter-Request (55), length 35:
              Subnet-Mask (1), Time-Zone (2), Default-Gateway (3), Time-Server (4)
              IEN-Name-Server (5), Domain-Name-Server (6), Hostname (12), BS (13)
              Domain-Name (15), RP (17), EP (18), RSZ (22)
              TTL (23), BR (28), YD (40), YS (41)
              NTP (42), Vendor-Option (43), Requested-IP (50), Lease-Time (51)
              Server-ID (54), RN (58), RB (59), Vendor-Class (60)
              TFTP (66), BF (67), GUID (97), Unknown (128)
              Unknown (129), Unknown (130), Unknown (131), Unknown (132)
              Unknown (133), Unknown (134), Unknown (135)
            GUID (97), length 17: 0.0.0.0.0.0.0.0.0.0.0.0.37.144.213.191.40
            NDI (94), length 3: 1.3.16
            ARCH (93), length 2: 7
            Vendor-Class (60), length 32: "PXEClient:Arch:00007:UNDI:003016"
            END (255), length 0
10:41:43.602882 IP (tos 0x0, ttl 64, id 51869, offset 0, flags [none], proto UDP (17), length 387)
    0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:25:90:d5:bf:28 (oui Unknown), length 359, xid 0x4371427b, Flags [Broadcast] (0x8000)
          Client-Ethernet-Address 00:25:90:d5:bf:28 (oui Unknown)
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Server-ID (54), length 4: 192.168.5.1
            Requested-IP (50), length 4: 192.168.5.127
            MSZ (57), length 2: 65280
            Parameter-Request (55), length 35:
              Subnet-Mask (1), Time-Zone (2), Default-Gateway (3), Time-Server (4)
              IEN-Name-Server (5), Domain-Name-Server (6), Hostname (12), BS (13)
              Domain-Name (15), RP (17), EP (18), RSZ (22)
              TTL (23), BR (28), YD (40), YS (41)
              NTP (42), Vendor-Option (43), Requested-IP (50), Lease-Time (51)
              Server-ID (54), RN (58), RB (59), Vendor-Class (60)
              TFTP (66), BF (67), GUID (97), Unknown (128)
              Unknown (129), Unknown (130), Unknown (131), Unknown (132)
              Unknown (133), Unknown (134), Unknown (135)
            GUID (97), length 17: 0.0.0.0.0.0.0.0.0.0.0.0.37.144.213.191.40
            NDI (94), length 3: 1.3.16
            ARCH (93), length 2: 7
            Vendor-Class (60), length 32: "PXEClient:Arch:00007:UNDI:003016"
            END (255), length 0
10:41:43.610692 IP (tos 0x0, ttl 64, id 51870, offset 0, flags [none], proto UDP (17), length 86)
    192.168.5.127.direcpc-dll > controller-0.provisioning.openstack.lab.tftp: [udp sum ok] TFTP, length 58, RRQ "snponly.efiM-}^DM-@M-(^ELy^N M-)M-~M-)M-~M-@M-(^Ed" octet tsize 0 blksize 1468
^C

```