sonic-buildimage/files/image_config/interfaces/interfaces.j2

#
{% block banner %}
# =============== Managed by SONiC Config Engine DO NOT EDIT! ===============
# generated from /usr/share/sonic/templates/interfaces.j2 using sonic-cfggen
# file: /etc/network/interfaces
#
{% endblock banner %}
{% block mgmt_vrf %}
{% if (MGMT_VRF_CONFIG) and (MGMT_VRF_CONFIG['vrf_global']['mgmtVrfEnabled'] == "true") %}
auto mgmt
iface mgmt
    vrf-table 5000
# The loopback network interface for mgmt VRF that is required for applications like NTP
    up ip link add lo-m type dummy
    up ip link set dev lo-m master mgmt
    up ip addr add 127.0.0.1/16 dev lo-m
    up ip link set lo-m up
    down ip link delete dev lo-m
{% endif %}
{% endblock mgmt_vrf %}
{% block loopback %}
# The loopback network interface
auto lo
iface lo inet loopback
   address 127.0.0.1
   netmask 255.255.0.0
   scope host
   post-up ip addr del 127.0.0.1/8 dev lo
   pre-down ip addr add 127.0.0.1/8 dev lo
{% endblock loopback %}
{% block mgmt_interface %}

# The management network interface
{% if (ZTP_DHCP_DISABLED is not defined) and (ZTP is defined) and (ZTP['mode'] is defined and ZTP['mode']['profile'] == 'active') %}
auto eth0


# ZTP out-of-band interface
allow-hotplug eth0
{% if ZTP['mode']['ipv4'] == 'true' %}
iface eth0 inet dhcp
{% endif %}
{% if ZTP['mode']['ipv6'] == 'true' %}
iface eth0 inet6 dhcp
    up sysctl net.ipv6.conf.eth0.accept_ra=1
    down sysctl net.ipv6.conf.eth0.accept_ra=0
{% endif %}

{% if ZTP['mode']['inband'] == 'true' %}
{% for port in PORT %}

# ZTP in-band interface {{ port }}
auto {{ port }}
allow-hotplug {{ port }}
{% if PORT_DATA['PORT_TABLE:'+port] is defined and PORT_DATA['PORT_TABLE:'+port]['value']['oper_status'] == 'up' %}
{% if ZTP['mode']['ipv4'] == 'true' %}
iface {{ port }} inet dhcp
{% endif %}
{% if ZTP['mode']['ipv6'] == 'true' %}
iface {{ port }} inet6 dhcp
{% endif %}
{% endif %}
{% endfor %}
{% endif %}

{% else %}
{% if MGMT_INTERFACE %}
{% for (name, prefix) in MGMT_INTERFACE|pfx_filter|unique(attribute=0) %}
auto {{ name }}
{% endfor %}
{% for (name, prefix) in MGMT_INTERFACE|pfx_filter %}
iface {{ name }} {{ 'inet' if prefix | ipv4 else 'inet6' }} static
    address {{ prefix | ip }}
    netmask {{ prefix | netmask if prefix | ipv4 else prefix | prefixlen }}
    network {{ prefix | network }}
    broadcast {{ prefix | broadcast }}
{%     set vrf_table = 'default' %}
{% if (MGMT_VRF_CONFIG) and (MGMT_VRF_CONFIG['vrf_global']['mgmtVrfEnabled'] == "true") %}
{%     set vrf_table = '5000' %}
    vrf mgmt
{% endif %}
{% set force_mgmt_route_priority = 32764 %}
    ########## management network policy routing rules
    # management port up rules
    up ip {{ '-4' if prefix | ipv4 else '-6' }} route add default via {{ MGMT_INTERFACE[(name, prefix)]['gwaddr'] }} dev {{ name }} table {{ vrf_table }} metric 201
    up ip {{ '-4' if prefix | ipv4 else '-6' }} route add {{ prefix | network }}/{{ prefix | prefixlen }} dev {{ name }} table {{ vrf_table }}
    up ip {{ '-4' if prefix | ipv4 else '-6' }} rule add pref {{ force_mgmt_route_priority + 1 }} from {{ prefix | ip }}/{{ '32' if prefix | ipv4 else '128' }} table {{ vrf_table }}
{% for route in MGMT_INTERFACE[(name, prefix)]['forced_mgmt_routes'] %}
    up ip rule add pref {{ force_mgmt_route_priority }} to {{ route }} table {{ vrf_table }}
{% endfor %}
{% if prefix | ipv6 and vrf_table == 'default'%}
    # IPV6 default table not add to lookup by default, management server need this to access IPV6 address when BGP shutdown
    up ip -6 rule add pref {{ force_mgmt_route_priority + 3 }} lookup {{ vrf_table }}
{% endif %}
    # management port down rules
    pre-down ip {{ '-4' if prefix | ipv4 else '-6' }} route delete default via {{ MGMT_INTERFACE[(name, prefix)]['gwaddr'] }} dev {{ name }} table {{ vrf_table }}
    pre-down ip {{ '-4' if prefix | ipv4 else '-6' }} route delete {{ prefix | network }}/{{ prefix | prefixlen }} dev {{ name }} table {{ vrf_table }}
    pre-down ip {{ '-4' if prefix | ipv4 else '-6' }} rule delete pref {{ force_mgmt_route_priority + 1 }} from {{ prefix | ip }}/{{ '32' if prefix | ipv4 else '128' }} table {{ vrf_table }}
{% for route in MGMT_INTERFACE[(name, prefix)]['forced_mgmt_routes'] %}
    pre-down ip rule delete pref {{ force_mgmt_route_priority }} to {{ route }} table {{ vrf_table }}
{% endfor %}
{% if prefix | ipv6 and vrf_table == 'default'%}
    pre-down ip -6 rule delete pref {{ force_mgmt_route_priority + 3 }} lookup {{ vrf_table }}
{% endif %}
{# TODO: COPP policy type rules #}
{% endfor %}
{% else %}
auto eth0
iface eth0 inet dhcp
    metric 202
{% if (MGMT_VRF_CONFIG) and (MGMT_VRF_CONFIG['vrf_global']['mgmtVrfEnabled'] == "true") %}
    vrf mgmt
{% endif %}
iface eth0 inet6 dhcp
    up sysctl net.ipv6.conf.eth0.accept_ra=1
    down sysctl net.ipv6.conf.eth0.accept_ra=0
{% endif %}
{% endif %}
#
source /etc/network/interfaces.d/*
#
{% endblock mgmt_interface %}