# l3\_agent.ini

L3 agent 相关的配置信息。 当存在外部网桥的时候，每个 agent 最多只能关联到一个外部网络。

```
[DEFAULT]
# Show debugging output in log (sets DEBUG log level output)
# debug = False

# L3 requires that an interface driver be set. Choose the one that best
# matches your plugin.
# interface_driver =

# Example of interface_driver option for OVS based plugins (OVS, Ryu, NEC)
# that supports L3 agent
# interface_driver = neutron.agent.linux.interface.OVSInterfaceDriver

# Use veth for an OVS interface or not.
# Support kernels with limited namespace support
# (e.g. RHEL 6.5) so long as ovs_use_veth is set to True.
# ovs_use_veth = False

# Example of interface_driver option for LinuxBridge
# interface_driver = neutron.agent.linux.interface.BridgeInterfaceDriver

# Allow overlapping IP (Must have kernel build with CONFIG_NET_NS=y and
# iproute2 package that supports namespaces).
# use_namespaces = True

# If use_namespaces is set as False then the agent can only configure one router.

# This is done by setting the specific router_id.
# router_id =

# When external_network_bridge is set, each L3 agent can be associated
# with no more than one external network. This value should be set to the UUID
# of that external network. To allow L3 agent support multiple external
# networks, both the external_network_bridge and gateway_external_network_id
# must be left empty.
# gateway_external_network_id =

# Indicates that this L3 agent should also handle routers that do not have
# an external network gateway configured.  This option should be True only
# for a single agent in a Neutron deployment, and may be False for all agents
# if all routers must have an external network gateway
# handle_internal_only_routers = True

# Name of bridge used for external network traffic. This should be set to
# empty value for the linux bridge. when this parameter is set, each L3 agent
# can be associated with no more than one external network.
# external_network_bridge = br-ex

# TCP Port used by Neutron metadata server
# metadata_port = 9697

# Send this many gratuitous ARPs for HA setup. Set it below or equal to 0
# to disable this feature.
# send_arp_for_ha = 3

# seconds between re-sync routers' data if needed
# periodic_interval = 40

# seconds to start to sync routers' data after
# starting agent
# periodic_fuzzy_delay = 5

# enable_metadata_proxy, which is true by default, can be set to False
# if the Nova metadata server is not available
# enable_metadata_proxy = True

# Location of Metadata Proxy UNIX domain socket
# metadata_proxy_socket = $state_path/metadata_proxy

# router_delete_namespaces, which is false by default, can be set to True if
# namespaces can be deleted cleanly on the host running the L3 agent.
# Do not enable this until you understand the problem with the Linux iproute
# utility mentioned in https://bugs.launchpad.net/neutron/+bug/1052535 and
# you are sure that your version of iproute does not suffer from the problem.
# If True, namespaces will be deleted when a router is destroyed.
# router_delete_namespaces = False

# Timeout for ovs-vsctl commands.
# If the timeout expires, ovs commands will fail with ALARMCLOCK error.
# ovs_vsctl_timeout = 10

# The working mode for the agent. Allowed values are:
# - legacy: this preserves the existing behavior where the L3 agent is
#   deployed on a centralized networking node to provide L3 services
#   like DNAT, and SNAT. Use this mode if you do not want to adopt DVR.
# - dvr: this mode enables DVR functionality, and must be used for an L3
#   agent that runs on a compute host.
# - dvr_snat: this enables centralized SNAT support in conjunction with
#   DVR. This mode must be used for an L3 agent running on a centralized
#   node (or in single-host deployments, e.g. devstack).
# agent_mode = legacy

# Location to store keepalived and all HA configurations
# ha_confs_path = $state_path/ha_confs

# VRRP authentication type AH/PASS
# ha_vrrp_auth_type = PASS

# VRRP authentication password
# ha_vrrp_auth_password =

# The advertisement interval in seconds
# ha_vrrp_advert_int = 2
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://yeasy.gitbook.io/openstack_code_neutron/etc/l3_agentini.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.