Merged latest 201911 to 201911-t0

build_debian.sh

@@ -301,7 +301,8 @@ sudo LANG=C DEBIAN_FRONTEND=noninteractive chroot $FILESYSTEM_ROOT apt-get -y in
     ipmitool                \
     ndisc6                  \
     makedumpfile            \
-    conntrack
+    conntrack               \
+    jq
 
 
 if [[ $CONFIGURED_ARCH == amd64 ]]; then

device/mellanox/x86_64-mlnx_msn2700-r0/pmon_daemon_control.json

@@ -1,5 +1,6 @@
 {
     "skip_ledd": true,
-    "skip_fancontrol": true
+    "skip_fancontrol": true,
+    "delay_xcvrd": true
 }
 

dockers/docker-dhcp-relay/Dockerfile.j2

@@ -25,7 +25,7 @@ RUN apt-get clean -y         && \
     rm -rf /debs
 
 COPY ["docker_init.sh", "start.sh", "/usr/bin/"]
-COPY ["docker-dhcp-relay.supervisord.conf.j2", "wait_for_intf.sh.j2", "/usr/share/sonic/templates/"]
+COPY ["docker-dhcp-relay.supervisord.conf.j2", "port-name-alias-map.txt.j2", "wait_for_intf.sh.j2", "/usr/share/sonic/templates/"]
 COPY ["files/supervisor-proc-exit-listener", "/usr/bin"]
 COPY ["critical_processes", "/etc/supervisor"]
 

dockers/docker-dhcp-relay/docker_init.sh

@@ -2,15 +2,21 @@
 
 # Generate supervisord config file
 mkdir -p /etc/supervisor/conf.d/
-sonic-cfggen -d -t /usr/share/sonic/templates/docker-dhcp-relay.supervisord.conf.j2 > /etc/supervisor/conf.d/docker-dhcp-relay.supervisord.conf
 
-# Generate the script that waits for all interfaces to come up and make it executable
-sonic-cfggen -d -t /usr/share/sonic/templates/wait_for_intf.sh.j2 > /usr/bin/wait_for_intf.sh
-chmod +x /usr/bin/wait_for_intf.sh
+# Generate the following files from templates:
+# 1. supervisord configuration 
+# 2. wait_for_intf.sh, which waits for all interfaces to come up
+# 3. port-to-alias name map
+CFGGEN_PARAMS=" \
+    -d \
+    -t /usr/share/sonic/templates/docker-dhcp-relay.supervisord.conf.j2,/etc/supervisor/conf.d/docker-dhcp-relay.supervisord.conf \
+    -t /usr/share/sonic/templates/wait_for_intf.sh.j2,/usr/bin/wait_for_intf.sh \
+    -t /usr/share/sonic/templates/port-name-alias-map.txt.j2,/tmp/port-name-alias-map.txt \
+"
+sonic-cfggen $CFGGEN_PARAMS
 
-# Generate port name-alias map for isc-dhcp-relay to parse. Each line contains one
-# name-alias pair of the form "<name> <alias>"
-sonic-cfggen -d --var-json "PORT" | python -c "import sys, json, os; [sys.stdout.write('%s %s\n' % (k, v['alias'] if 'alias' in v else k)) for (k, v) in json.load(sys.stdin).iteritems()]" > /tmp/port-name-alias-map.txt
+# Make the script that waits for all interfaces to come up executable
+chmod +x /usr/bin/wait_for_intf.sh
 
 # The docker container should start this script as PID 1, so now that supervisord is
 # properly configured, we exec supervisord so that it runs as PID 1 for the

dockers/docker-dhcp-relay/port-name-alias-map.txt.j2

@@ -0,0 +1,5 @@
+{# Generate port name-alias map for isc-dhcp-relay to parse. Each line contains one #}
+{#  name-alias pair of the form "<name> <alias>" #}
+{% for port, config in PORT.items() %}
+    {{- port }} {% if "alias" in config %}{{ config["alias"] }}{% else %}{{ port }}{% endif %} {{- "\n" -}}
+{% endfor -%}

dockers/docker-fpm-frr/frr/frr_vars.j2

@@ -0,0 +1 @@
+{{ DEVICE_METADATA["localhost"]["docker_routing_config_mode"] }}

dockers/docker-fpm-frr/start.sh

@@ -1,8 +1,21 @@
 #!/usr/bin/env bash
 
 mkdir -p /etc/frr
-
-CONFIG_TYPE=`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["docker_routing_config_mode"]'`
+mkdir -p /etc/supervisor/conf.d
+
+CFGGEN_PARAMS=" \
+    -d \
+    -y /etc/sonic/constants.yml \
+    -t /usr/share/sonic/templates/supervisord/frr_vars.j2 \
+    -t /usr/share/sonic/templates/supervisord/supervisord.conf.j2,/etc/supervisor/conf.d/supervisord.conf \
+    -t /usr/share/sonic/templates/bgpd/bgpd.conf.j2,/etc/frr/bgpd.conf \
+    -t /usr/share/sonic/templates/zebra/zebra.conf.j2,/etc/frr/zebra.conf \
+    -t /usr/share/sonic/templates/staticd/staticd.conf.j2,/etc/frr/staticd.conf \
+    -t /usr/share/sonic/templates/frr.conf.j2,/etc/frr/frr.conf \
+    -t /usr/share/sonic/templates/isolate.j2,/usr/sbin/bgp-isolate \
+    -t /usr/share/sonic/templates/unisolate.j2,/usr/sbin/bgp-unisolate \
+"
+CONFIG_TYPE=$(sonic-cfggen $CFGGEN_PARAMS)
 
 update_default_gw()
 {
@@ -35,24 +48,18 @@ if [[ ! -z "$NAMESPACE_ID" ]]; then
 fi
 
 if [ -z "$CONFIG_TYPE" ] || [ "$CONFIG_TYPE" == "separated" ]; then
-    sonic-cfggen -d -t /usr/share/sonic/templates/bgpd/bgpd.conf.j2 -y /etc/sonic/constants.yml > /etc/frr/bgpd.conf
-    sonic-cfggen -d -t /usr/share/sonic/templates/zebra/zebra.conf.j2 > /etc/frr/zebra.conf
-    sonic-cfggen -d -t /usr/share/sonic/templates/staticd/staticd.conf.j2 > /etc/frr/staticd.conf
     echo "no service integrated-vtysh-config" > /etc/frr/vtysh.conf
     rm -f /etc/frr/frr.conf
 elif [ "$CONFIG_TYPE" == "unified" ]; then
-    sonic-cfggen -d -y /etc/sonic/constants.yml -t /usr/share/sonic/templates/frr.conf.j2 >/etc/frr/frr.conf
     echo "service integrated-vtysh-config" > /etc/frr/vtysh.conf
     rm -f /etc/frr/bgpd.conf /etc/frr/zebra.conf /etc/frr/staticd.conf
 fi
 
 chown -R frr:frr /etc/frr/
 
-sonic-cfggen -d -t /usr/share/sonic/templates/isolate.j2 > /usr/sbin/bgp-isolate
 chown root:root /usr/sbin/bgp-isolate
 chmod 0755 /usr/sbin/bgp-isolate
 
-sonic-cfggen -d -t /usr/share/sonic/templates/unisolate.j2 > /usr/sbin/bgp-unisolate
 chown root:root /usr/sbin/bgp-unisolate
 chmod 0755 /usr/sbin/bgp-unisolate
 

dockers/docker-fpm-gobgp/start.sh

@@ -1,14 +1,19 @@
 #!/usr/bin/env bash
 
 mkdir -p /etc/quagga
-sonic-cfggen -d -t /usr/share/sonic/templates/gobgpd.conf.j2 > /etc/gobgp/gobgpd.conf
-sonic-cfggen -d -t /usr/share/sonic/templates/zebra.conf.j2 > /etc/quagga/zebra.conf
 
-sonic-cfggen -d -t /usr/share/sonic/templates/isolate.j2 > /usr/sbin/bgp-isolate
+CFGGEN_PARAMS=" \
+    -d \
+    -t /usr/share/sonic/templates/gobgpd.conf.j2,/etc/gobgp/gobgpd.conf \
+    -t /usr/share/sonic/templates/zebra.conf.j2,/etc/quagga/zebra.conf \
+    -t /usr/share/sonic/templates/isolate.j2,/usr/sbin/bgp-isolate \
+    -t /usr/share/sonic/templates/unisolate.j2,/usr/sbin/bgp-unisolate \
+"
+sonic-cfggen $CFGGEN_PARAMS
+
 chown root:root /usr/sbin/bgp-isolate
 chmod 0755 /usr/sbin/bgp-isolate
 
-sonic-cfggen -d -t /usr/share/sonic/templates/unisolate.j2 > /usr/sbin/bgp-unisolate
 chown root:root /usr/sbin/bgp-unisolate
 chmod 0755 /usr/sbin/bgp-unisolate
 

dockers/docker-fpm-quagga/start.sh

@@ -1,15 +1,20 @@
 #!/usr/bin/env bash
 
 mkdir -p /etc/quagga
-sonic-cfggen -d -y /etc/sonic/constants.yml -t /usr/share/sonic/templates/bgpd.conf.j2 > /etc/quagga/bgpd.conf
 
-sonic-cfggen -d -t /usr/share/sonic/templates/zebra.conf.j2 > /etc/quagga/zebra.conf
+CFGGEN_PARAMS=" \
+    -d \
+    -y /etc/sonic/constants.yml \
+    -t /usr/share/sonic/templates/bgpd.conf.j2,/etc/quagga/bgpd.conf \
+    -t /usr/share/sonic/templates/zebra.conf.j2,/etc/quagga/zebra.conf \
+    -t /usr/share/sonic/templates/isolate.j2,/usr/sbin/bgp-isolate \
+    -t /usr/share/sonic/templates/unisolate.j2,/usr/sbin/bgp-unisolate \
+"
+sonic-cfggen $CFGGEN_PARAMS
 
-sonic-cfggen -d -t /usr/share/sonic/templates/isolate.j2 > /usr/sbin/bgp-isolate
 chown root:root /usr/sbin/bgp-isolate
 chmod 0755 /usr/sbin/bgp-isolate
 
-sonic-cfggen -d -t /usr/share/sonic/templates/unisolate.j2 > /usr/sbin/bgp-unisolate
 chown root:root /usr/sbin/bgp-unisolate
 chmod 0755 /usr/sbin/bgp-unisolate
 

dockers/docker-orchagent/Dockerfile.j2

@@ -63,7 +63,7 @@ RUN apt-get clean -y        && \
     rm -rf /debs
 
 COPY ["files/arp_update", "/usr/bin"]
-COPY ["arp_update.conf", "/usr/share/sonic/templates/"]
+COPY ["arp_update.conf", "files/arp_update_vars.j2", "/usr/share/sonic/templates/"]
 COPY ["enable_counters.py", "/usr/bin"]
 COPY ["docker-init.sh", "orchagent.sh", "swssconfig.sh", "/usr/bin/"]
 COPY ["supervisord.conf", "/etc/supervisor/conf.d/"]

dockers/docker-orchagent/docker-init.sh

@@ -2,18 +2,23 @@
 
 mkdir -p /etc/swss/config.d/
 
-sonic-cfggen -d -y /etc/sonic/sonic_version.yml -t /usr/share/sonic/templates/switch.json.j2 > /etc/swss/config.d/switch.json
-sonic-cfggen -d -t /usr/share/sonic/templates/ipinip.json.j2 > /etc/swss/config.d/ipinip.json
-sonic-cfggen -d -t /usr/share/sonic/templates/ports.json.j2 > /etc/swss/config.d/ports.json
-sonic-cfggen -d -t /usr/share/sonic/templates/copp.json.j2 > /etc/swss/config.d/00-copp.config.json
+CFGGEN_PARAMS=" \
+    -d \
+    -y /etc/sonic/constants.yml \
+    -t /usr/share/sonic/templates/switch.json.j2,/etc/swss/config.d/switch.json \
+    -t /usr/share/sonic/templates/ipinip.json.j2,/etc/swss/config.d/ipinip.json \
+    -t /usr/share/sonic/templates/ports.json.j2,/etc/swss/config.d/ports.json \
+    -t /usr/share/sonic/templates/copp.json.j2,/etc/swss/config.d/00-copp.config.json \
+    -t /usr/share/sonic/templates/vlan_vars.j2 \
+"
+VLAN=$(sonic-cfggen $CFGGEN_PARAMS)
 
 # Executed HWSKU specific initialization tasks.
 if [ -x /usr/share/sonic/hwsku/hwsku-init ]; then
     /usr/share/sonic/hwsku/hwsku-init
 fi
 
 # Start arp_update when VLAN exists
-VLAN=`sonic-cfggen -d -v 'VLAN.keys() | join(" ") if VLAN'`
 if [ "$VLAN" != "" ]; then
     cp /usr/share/sonic/templates/arp_update.conf /etc/supervisor/conf.d/
 fi

dockers/docker-orchagent/vlan_vars.j2

@@ -0,0 +1 @@
+{%- if VLAN -%}{{- VLAN.keys() | join(' ') -}}{%- endif -%}

dockers/docker-platform-monitor/docker-pmon.supervisord.conf.j2

@@ -79,7 +79,11 @@ dependent_startup_wait_for=start:exited
 
 {% if not skip_xcvrd %}
 [program:xcvrd]
+{% if delay_xcvrd %}
+command=bash -c "sleep 30 && /usr/bin/xcvrd"
+{% else %}
 command=/usr/bin/xcvrd
+{% endif %}
 priority=6
 autostart=false
 autorestart=false

dockers/docker-router-advertiser/docker-init.sh

@@ -1,13 +1,17 @@
 #!/usr/bin/env bash
 
 mkdir -p /etc/supervisor/conf.d
-sonic-cfggen -d -t /usr/share/sonic/templates/docker-router-advertiser.supervisord.conf.j2 > /etc/supervisor/conf.d/supervisord.conf
 
-# Generate /etc/radvd.conf config file
-sonic-cfggen -d -t /usr/share/sonic/templates/radvd.conf.j2 > /etc/radvd.conf
+# Generate supervisord router advertiser config, /etc/radvd.conf config file, and
+# the script that waits for pertinent interfaces to come up and make it executable
+CFGGEN_PARAMS=" \
+    -d \
+    -t /usr/share/sonic/templates/docker-router-advertiser.supervisord.conf.j2,/etc/supervisor/conf.d/supervisord.conf \
+    -t /usr/share/sonic/templates/radvd.conf.j2,/etc/radvd.conf \
+    -t /usr/share/sonic/templates/wait_for_intf.sh.j2,/usr/bin/wait_for_intf.sh \
+"
+sonic-cfggen $CFGGEN_PARAMS
 
-# Generate the script that waits for pertinent interfaces to come up and make it executable
-sonic-cfggen -d -t /usr/share/sonic/templates/wait_for_link.sh.j2 > /usr/bin/wait_for_link.sh
-chmod +x /usr/bin/wait_for_link.sh
+chmod +x /usr/bin/wait_for_intf.sh
 
 exec /usr/bin/supervisord

dockers/docker-snmp-sv2/start.sh

@@ -1,10 +1,16 @@
 #!/usr/bin/env bash
 
-mkdir -p /etc/ssw
-sonic-cfggen -d -y /etc/sonic/sonic_version.yml -t /usr/share/sonic/templates/sysDescription.j2 > /etc/ssw/sysDescription
+mkdir -p /etc/ssw /etc/snmp
 
-mkdir -p /etc/snmp
-sonic-cfggen -d -y /etc/sonic/snmp.yml -t /usr/share/sonic/templates/snmpd.conf.j2 > /etc/snmp/snmpd.conf
+SONIC_CFGGEN_ARGS=" \
+    -d \
+    -y /etc/sonic/sonic_version.yml \
+    -t /usr/share/sonic/templates/sysDescription.j2,/etc/ssw/sysDescription \
+    -y /etc/sonic/snmp.yml \
+    -t /usr/share/sonic/templates/snmpd.conf.j2,/etc/snmp/snmpd.conf \
+"
+
+sonic-cfggen $SONIC_CFGGEN_ARGS
 
 mkdir -p /var/sonic
 echo "# Config files managed by sonic-config-engine" > /var/sonic/config_status

dockers/docker-sonic-mgmt-framework/Dockerfile.j2

@@ -34,6 +34,7 @@ debs/{{ deb }}{{' '}}
 {%- endfor %}
 
 COPY ["start.sh", "rest-server.sh", "/usr/bin/"]
+COPY ["mgmt_vars.j2", "/usr/share/sonic/templates/"]
 COPY ["supervisord.conf", "/etc/supervisor/conf.d/"]
 
 RUN apt-get clean -y; apt-get autoclean -y; apt-get autoremove -y

dockers/docker-sonic-mgmt-framework/mgmt_vars.j2

@@ -0,0 +1,4 @@
+{
+    "rest_server": {% if REST_SERVER is defined and "default" in RESET_SERVER.keys() %}{{ REST_SERVER['default'] }}{% else %}""{% endif %},
+    "x509" : {% if "x509" in DEVICE_METADATA.keys() %}{{ DEVICE_METADATA["x509"] }}{% else %}""{% endif %}
+}

dockers/docker-sonic-mgmt-framework/rest-server.sh

@@ -1,28 +1,39 @@
 #!/usr/bin/env bash
 
 # Startup script for SONiC Management REST Server
+EXIT_MGMT_VARS_FILE_NOT_FOUND=1
+MGMT_VARS_FILE=/usr/share/sonic/templates/mgmt_vars.j2
 
-SERVER_PORT=
-LOG_LEVEL=
-CLIENT_AUTH=
-SERVER_CRT=
-SERVER_KEY=
-CA_CERT=
-
-# Read basic server settings from REST_SERVER|default entry
-HAS_REST_CONFIG=$(sonic-cfggen -d -v "1 if REST_SERVER and REST_SERVER['default']")
-if [ "$HAS_REST_CONFIG" == "1" ]; then
-    SERVER_PORT=$(sonic-cfggen -d -v "REST_SERVER['default']['port']")
-    CLIENT_AUTH=$(sonic-cfggen -d -v "REST_SERVER['default']['client_auth']")
-    LOG_LEVEL=$(sonic-cfggen -d -v "REST_SERVER['default']['log_level']")
+if [ ! -f "$MGMT_VARS_FILE" ]; then
+    echo "Mgmt vars template file not found"
+    exit $EXIT_MGMT_VARS_FILE_NOT_FOUND
+fi
+
+# Read basic server settings from mgmt vars entries
+MGMT_VARS=$(sonic-cfggen -d -t $MGMT_VARS_FILE)
+MGMT_VARS=${MGMT_VARS//[\']/\"}
+
+REST_SERVER=$(echo $MGMT_VARS | jq -r '.rest_server')
+
+if [ -n "$REST_SERVER" ]; then
+    SERVER_PORT=$(echo $REST_SERVER | jq -r '.port')
+    CLIENT_AUTH=$(echo $REST_SERVER | jq -r '.client_auth')
+    LOG_LEVEL=$(echo $REST_SERVER | jq -r '.log_level')
+
+    SERVER_CRT=$(echo $REST_SERVER | jq -r '.server_crt')
+    SERVER_KEY=$(echo $REST_SERVER | jq -r '.server_key')
+    CA_CRT=$(echo $REST_SERVER | jq -r '.ca_crt')
+fi
+
+if [[ -z $SERVER_CRT ]] && [[ -z $SERVER_KEY ]] && [[ -z $CA_CRT ]]; then
+    X509=$(echo $MGMT_VARS | jq -r '.x509')
 fi
 
 # Read certificate file paths from DEVICE_METADATA|x509 entry.
-HAS_X509_CONFIG=$(sonic-cfggen -d -v "1 if DEVICE_METADATA and DEVICE_METADATA['x509']")
-if [ "$HAS_X509_CONFIG" == "1" ]; then
-    SERVER_CRT=$(sonic-cfggen -d -v "DEVICE_METADATA['x509']['server_crt']")
-    SERVER_KEY=$(sonic-cfggen -d -v "DEVICE_METADATA['x509']['server_key']")
-    CA_CRT=$(sonic-cfggen -d -v "DEVICE_METADATA['x509']['ca_crt']")
+if [ -n "$X509" ]; then
+    SERVER_CRT=$(echo $X509 | jq -r '.server_crt')
+    SERVER_KEY=$(echo $X509 | jq -r '.server_key')
+    CA_CRT=$(echo $X509 | jq -r '.ca_crt')
 fi
 
 # Create temporary server certificate if they not configured in ConfigDB

files/build_templates/arp_update_vars.j2

@@ -0,0 +1,5 @@
+{
+    "interface": "{% for (name, prefix) in INTERFACE|pfx_filter %}{% if prefix|ipv6 %}{{ name }} {% endif %}{% endfor %}",
+    "pc_interface" : "{% for (name, prefix) in PORTCHANNEL_INTERFACE|pfx_filter %}{% if prefix|ipv6 %}{{ name }} {% endif %}{% endfor %}",
+    "vlan" : "{% if VLAN %}{{ VLAN.keys() | join(' ') }}{% endif %}"
+}

files/image_config/interfaces/interfaces-config.sh

@@ -18,8 +18,14 @@ else
     echo "{ \"ZTP_DHCP_DISABLED\" : \"true\" }" > /tmp/ztp_input.json
 fi
 
-# Create /e/n/i file for existing and active interfaces
-sonic-cfggen -d -j /tmp/ztp_input.json -t /usr/share/sonic/templates/interfaces.j2 > /etc/network/interfaces
+# Create /e/n/i file for existing and active interfaces, dhcp6 sytcl.conf and dhclient.conf
+CFGGEN_PARAMS=" \
+    -d -j /tmp/ztp_input.json \
+    -t /usr/share/sonic/templates/interfaces.j2,/etc/network/interfaces \
+    -t /usr/share/sonic/templates/90-dhcp6-systcl.conf.j2,/etc/sysctl.d/90-dhcp6-systcl.conf \
+    -t /usr/share/sonic/templates/dhclient.conf.j2,/etc/dhcp/dhclient.conf \
+"
+sonic-cfggen $CFGGEN_PARAMS
 
 [ -f /var/run/dhclient.eth0.pid ] && kill `cat /var/run/dhclient.eth0.pid` && rm -f /var/run/dhclient.eth0.pid
 [ -f /var/run/dhclient6.eth0.pid ] && kill `cat /var/run/dhclient6.eth0.pid` && rm -f /var/run/dhclient6.eth0.pid
@@ -28,11 +34,9 @@ for intf_pid in $(ls -1 /var/run/dhclient*.Ethernet*.pid 2> /dev/null); do
     [ -f ${intf_pid} ] && kill `cat ${intf_pid}` && rm -f ${intf_pid}
 done
 
-sonic-cfggen -d -j /tmp/ztp_input.json -t /usr/share/sonic/templates/90-dhcp6-systcl.conf.j2 > /etc/sysctl.d/90-dhcp6-systcl.conf
 # Read sysctl conf files again
 sysctl -p /etc/sysctl.d/90-dhcp6-systcl.conf
 
-sonic-cfggen -d -j /tmp/ztp_input.json -t /usr/share/sonic/templates/dhclient.conf.j2 > /etc/dhcp/dhclient.conf
 systemctl restart networking
 
 # Clean-up created files

files/scripts/arp_update

@@ -7,12 +7,13 @@
 # Send gratuitous ARP/NDP requests to VLAN member neighbors to refresh
 # the ipv4/ipv6 neighbors state.
 
+ARP_UPDATE_VARS_FILE="/usr/share/sonic/templates/arp_update_vars.j2"
+
 while /bin/true; do
   # find L3 interfaces which are UP, send ipv6 multicast pings
-  echo "{% for (name, prefix) in INTERFACE|pfx_filter %} {{name}} {% endfor %}" > /tmp/intf_tmp.j2
-  INTERFACE=`sonic-cfggen -d -t /tmp/intf_tmp.j2`
-  echo "{% for (name, prefix) in PORTCHANNEL_INTERFACE|pfx_filter %} {{name}} {% endfor %}" > /tmp/pc_intf_tmp.j2
-  PC_INTERFACE=`sonic-cfggen -d -t /tmp/pc_intf_tmp.j2`
+  ARP_UPDATE_VARS=$(sonic-cfggen -d -t ${ARP_UPDATE_VARS_FILE})
+  INTERFACE=$(echo $ARP_UPDATE_VARS | jq -r '.interface')
+  PC_INTERFACE=$(echo $ARP_UPDATE_VARS | jq -r '.pc_interface')
 
   ALL_INTERFACE="$INTERFACE $PC_INTERFACE"
   for intf in $ALL_INTERFACE; do
@@ -23,7 +24,7 @@ while /bin/true; do
       fi
   done
 
-  VLAN=`sonic-cfggen -d -v 'VLAN.keys() | join(" ") if VLAN'`
+  VLAN=$(echo $ARP_UPDATE_VARS | jq -r '.vlan')
   for vlan in $VLAN; do
       # generate a list of arping commands:
       #   arping -q -w 0 -c 1 -i <VLAN interface> <IP 1>;