neutron/doc/source/ovn/dhcp_opts.rst
Eduardo Olivares d4b1b4a072 Fix typo in OVN SUPPORTED_DHCP_OPTS_MAPPING dictionary (ia-addr)
Closes-Bug: #1938569

Change-Id: I10e0834594f68e06244c393c00d0b3d840c45fc5
2021-07-30 17:05:40 +02:00

5.0 KiB

OVN supported DHCP options

This is a list of the current supported DHCP options in ML2/OVN:

IP version 4

Option name / code OVN value
arp-timeout arp_cache_timeout
bootfile-name bootfile_name
classless-static-route classless_static_route
default-ttl default_ttl
dns-server dns_server
domain-name domain_name
ethernet-encap ethernet_encap
ip-forward-enable ip_forward_enable
lease-time lease_time
log-server log_server
lpr-server lpr_server
ms-classless-static-route ms_classless_static_route
mtu mtu
netmask netmask
nis-server nis_server
ntp-server ntp_server
path-prefix path_prefix
policy-filter policy_filter
router-discovery router_discovery
router router
router-solicitation router_solicitation
server-id server_id
server-ip-address tftp_server_address
swap-server swap_server
T1 T1
T2 T2
tcp-ttl tcp_ttl
tcp-keepalive tcp_keepalive_interval
tftp-server-address tftp_server_address
tftp-server tftp_server
wpad wpad
1 netmask
3 router
6 dns_server
7 log_server
9 lpr_server
15 domain_name
16 swap_server
19 ip_forward_enable
21 policy_filter
23 default_ttl
26 mtu
31 router_discovery
32 router_solicitation
35 arp_cache_timeout
36 ethernet_encap
37 tcp_ttl
38 tcp_keepalive_interval
41 nis_server
42 ntp_server
51 lease_time
54 server_id
58 T1
59 T2
66 tftp_server
67 bootfile_name
121 classless_static_route
150 tftp_server_address
210 path_prefix
249 ms_classless_static_route
252 wpad

IP version 6

Option name / code OVN value
dns-server dns_server
domain-search domain_search
ia-addr ia_addr
server-id server_id
2 server_id
5 ia_addr
23 dns_server
24 domain_search

OVN Database information

In OVN the DHCP options are stored on a table called DHCP_Options in the OVN Northbound database.

Let's add a DHCP option to a Neutron port:

$ neutron port-update --extra-dhcp-opt opt_name='server-ip-address',opt_value='10.0.0.1' b4c3f265-369e-4bf5-8789-7caa9a1efb9c
Updated port: b4c3f265-369e-4bf5-8789-7caa9a1efb9c

To find that port in OVN we can use command below:

$ ovn-nbctl find Logical_Switch_Port name=b4c3f265-369e-4bf5-8789-7caa9a1efb9c
...
dhcpv4_options      : 5f00d1a2-c57d-4d1f-83ea-09bf8be13288
dhcpv6_options      : []
...

For DHCP, the columns that we care about are the dhcpv4_options and dhcpv6_options. These columns has the uuids of entries in the DHCP_Options table with the DHCP information for this port.

$ ovn-nbctl list DHCP_Options 5f00d1a2-c57d-4d1f-83ea-09bf8be13288
_uuid               : 5f00d1a2-c57d-4d1f-83ea-09bf8be13288
cidr                : "10.0.0.0/26"
external_ids        : {"neutron:revision_number"="0", port_id="b4c3f265-369e-4bf5-8789-7caa9a1efb9c", subnet_id="5157ed8b-e7f1-4c56-b789-fa420098a687"}
options             : {classless_static_route="{169.254.169.254/32,10.0.0.2, 0.0.0.0/0,10.0.0.1}", dns_server="{8.8.8.8}", domain_name="\"openstackgate.local\"", lease_time="43200", log_server="127.0.0.3", mtu="1442", router="10.0.0.1", server_id="10.0.0.1", server_mac="fa:16:3e:dc:57:22", tftp_server_address="10.0.0.1"}

Here you can see that the option tftp_server_address has been set in the options column. Note that, the tftp_server_address option is the OVN translated name for server-ip-address (option 150). Take a look at the table in this document to find out more about the supported options and their counterpart names in OVN.