[Dnsmasq-discuss] DHCPv6 solicit ignored by dnsmasq after UEFI -> iPXE -> Deploy ramdisk

Harald Jensås hjensas at redhat.com
Tue Nov 12 15:56:27 GMT 2019


When using DHCP-stateful addressing, radvd config below, UEFI
succesfully request/advertize 2x IP's and downloads the bootimage
(iPXE). UEFI (OVMF) then releases the addresses and iPXE then boots.

iPXE does one request/advertize and dowloads and boot the deploy
ramdisk (CentoOS 7). dhclient in CentOS 7 starts logging: "XMT: Solicit
on eth0, interval ...", dnsmasq ignores the DHCPv6 Solicit messages? I
don't understand why it's ignored? (Config files, and annotated traffic
dump + dnsmasq logs below.)


radvd.conf
----------
interface eth0 {
  AdvSendAdvert on;
  AdvManagedFlag on;
  AdvOtherConfigFlag on;
  AdvRASolicitedUnicast on;
  prefix fd12:3456:789a:1::1/64 {
    AdvAutonomous off;
    AdvOnLink on;
  };
};

dnsmasq.conf
------------
port=0
interface=br-ctlplane

dhcp-range=set:ctlplane-
subnet,fd12:3456:789a:1::aaaa,fd12:3456:789a:1::afff,64,10m
dhcp-option-force=tag:ctlplane-subnet,option:mtu,1450
dhcp-sequential-ip
dhcp-match=ipxe,175
dhcp-match=set:efi,option:client-arch,7
dhcp-match=set:efi,option:client-arch,9
dhcp-match=set:efi,option:client-arch,11
# dhcpv6s for Client System Architecture Type (61)
dhcp-match=set:efi6,option6:61,0007
dhcp-match=set:efi6,option6:61,0009
dhcp-match=set:efi6,option6:61,0011
dhcp-userclass=set:ipxe6,iPXE
# Client is already running iPXE; move to next stage of chainloading
dhcp-boot=tag:ipxe,http://[fd12:3456:789a:1::1]:8088/inspector.ipxe
dhcp-option=tag:ipxe6,option6:bootfile-url,
http://[fd12:3456:789a:1::1]:8088/inspector.ipxe
# Client is PXE booting over EFI without iPXE ROM; send EFI version of
iPXE chainloader
dhcp-boot=tag:efi,tag:!ipxe,ipxe.efi
dhcp-option=tag:efi6,tag:!ipxe6,option6:bootfile-url,t
ftp://[fd12:3456:789a:1::1]/ipxe.efi
# Client is running PXE over BIOS; send BIOS version of iPXE
chainloader
dhcp-boot=undionly.kpxe,localhost.localdomain,fd12:3456:789a:1::1

dhcp-hostsdir=/var/lib/ironic-inspector/dhcp-hostsdir





Immedeatly (OVFM initialize) and get's an IP
############################################

----
# Packet 3 from /home/hjensas/captur.pcap
- 4
- 2.200296
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 116
- Solicit XID: 0xc69bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c 
Nov 12 15:44:28 dnsmasq-dhcp[7]: DHCPSOLICIT(br-ctlplane)
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c

----
# Packet 4 from /home/hjensas/captur.pcap
- 5
- 2.201402
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 168
- Advertise XID: 0xc69bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c
IAA: fd12:3456:789a:1::aaaa
Nov 12 15:44:28 dnsmasq-dhcp[7]: DHCPADVERTISE(br-ctlplane)
fd12:3456:789a:1::aaaa
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

----
# Packet 5 from /home/hjensas/captur.pcap
- 6
- 2.202095
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 162
- Request XID: 0xc79bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaaa 
Nov 12 15:44:28 dnsmasq-dhcp[7]: DHCPREQUEST(br-ctlplane)
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

----
# Packet 6 from /home/hjensas/captur.pcap
- 7
- 2.206348
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 163
- Reply XID: 0xc79bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaaa 

Nov 12 15:44:28 dnsmasq-dhcp[7]: DHCPREPLY(br-ctlplane)
fd12:3456:789a:1::aaaa
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

Once IPv4 Fails. OVFM does another request and doewnload bootfile.
##################################################################

----
# Packet 12 from /home/hjensas/captur.pcap
- 13
- 59.909240
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 177
- Solicit XID: 0xc89bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c 
Nov 12 15:45:26 dnsmasq-dhcp[7]: DHCPSOLICIT(br-ctlplane)
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

----
# Packet 13 from /home/hjensas/captur.pcap
- 14
- 59.910248
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 209
- Advertise XID: 0xc89bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c
IAA: fd12:3456:789a:1::aaab 
Nov 12 15:45:26 dnsmasq-dhcp[7]: DHCPADVERTISE(br-ctlplane)
fd12:3456:789a:1::aaab
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

----
# Packet 14 from /home/hjensas/captur.pcap
- 15
- 64.900995
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 223
- Request XID: 0xc99bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaab 
Nov 12 15:45:31 dnsmasq-dhcp[7]: DHCPREQUEST(br-ctlplane)
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

----
# Packet 15 from /home/hjensas/captur.pcap
- 16
- 64.906111
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 204
- Reply XID: 0xc99bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaab 
Nov 12 15:45:31 dnsmasq-dhcp[7]: DHCPREPLY(br-ctlplane)
fd12:3456:789a:1::aaab
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 


Prior to booting boofile, OVMF releases both IP's.
##################################################

----
# Packet 16 from /home/hjensas/captur.pcap
- 17
- 64.906716
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 156
- Release XID: 0xca9bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaaa 
----
# Packet 17 from /home/hjensas/captur.pcap
- 18
- 64.914718
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 128
- Reply XID: 0xca9bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c 
Nov 12 15:45:31 dnsmasq-dhcp[7]: DHCPRELEASE(br-ctlplane)
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

----
# Packet 23 from /home/hjensas/captur.pcap
- 24
- 67.196950
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 156
- Release XID: 0xcb9bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaab 
----
# Packet 24 from /home/hjensas/captur.pcap
- 25
- 67.201832
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 128
- Reply XID: 0xcb9bce CID: 000490b3fe05c8ed7342a57d55a04f57ed5c 
Nov 12 15:45:33 dnsmasq-dhcp[7]: DHCPRELEASE(br-ctlplane)
00:04:90:b3:fe:05:c8:ed:73:42:a5:7d:55:a0:4f:57:ed:5c 

iPXE - Solicit, Adevertise, Request, Reply
##########################################

----
# Packet 26 from /home/hjensas/captur.pcap
- 27
- 69.370246
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 187
- Solicit XID: 0x95d050 CID: 000405feb390edc84273a57d55a04f57ed5c 
Nov 12 15:45:35 dnsmasq-dhcp[7]: DHCPSOLICIT(br-ctlplane)
00:04:05:fe:b3:90:ed:c8:42:73:a5:7d:55:a0:4f:57:ed:5c 
----
# Packet 27 from /home/hjensas/captur.pcap
- 28
- 69.370811
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 220
- Advertise XID: 0x95d050 CID: 000405feb390edc84273a57d55a04f57ed5c
IAA: fd12:3456:789a:1::aaaa 
Nov 12 15:45:35 dnsmasq-dhcp[7]: DHCPADVERTISE(br-ctlplane)
fd12:3456:789a:1::aaaa
00:04:05:fe:b3:90:ed:c8:42:73:a5:7d:55:a0:4f:57:ed:5c 
----
# Packet 28 from /home/hjensas/captur.pcap
- 29
- 69.371000
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 233
- Request XID: 0x95d050 CID: 000405feb390edc84273a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaaa 
Nov 12 15:45:35 dnsmasq-dhcp[7]: DHCPREQUEST(br-ctlplane)
00:04:05:fe:b3:90:ed:c8:42:73:a5:7d:55:a0:4f:57:ed:5c 
----
# Packet 29 from /home/hjensas/captur.pcap
- 30
- 69.375783
- fe80::5054:ff:fe49:dbf9
- fe80::5054:ff:fe3f:5cc0
- DHCPv6
- 215
- Reply XID: 0x95d050 CID: 000405feb390edc84273a57d55a04f57ed5c IAA:
fd12:3456:789a:1::aaaa 
Nov 12 15:45:35 dnsmasq-dhcp[7]: DHCPREPLY(br-ctlplane)
fd12:3456:789a:1::aaaa
00:04:05:fe:b3:90:ed:c8:42:73:a5:7d:55:a0:4f:57:ed:5c 



Deploy ramdisk boot's, can see it send DHCP solicit in tcpdump, but
dnsmasq silently ignores it?
----
# Packet 69 from /home/hjensas/captur.pcap
- 70
- 138.318610
- fe80::5054:ff:fe3f:5cc0
- ff02::1:2
- DHCPv6
- 118
- Solicit XID: 0xdbee92 CID: 000405feb390edc84273a57d55a04f57ed5c 
...
71	139.379089	fe80::5054:ff:fe3f:5cc0	ff02::1:2	DHCPv6	
118	Solicit XID: 0xdbee92 CID:
000405feb390edc84273a57d55a04f57ed5c 
73	141.602244	fe80::5054:ff:fe3f:5cc0	ff02::1:2	DHCPv6	
118	Solicit XID: 0xdbee92 CID:
000405feb390edc84273a57d55a04f57ed5c 
76	146.037419	fe80::5054:ff:fe3f:5cc0	ff02::1:2	DHCPv6	
118	Solicit XID: 0xdbee92 CID:
000405feb390edc84273a57d55a04f57ed5c 
77	154.670545	fe80::5054:ff:fe3f:5cc0	ff02::1:2	DHCPv6	
118	Solicit XID: 0xdbee92 CID:
000405feb390edc84273a57d55a04f57ed5c 





More information about the Dnsmasq-discuss mailing list