There is a command group 'az_networkfabric_externalnetwork'. This group of commands could 'manage external network resource'. The group of commands has global parameter '--debug' which means 'Increase logging verbosity to show all debug logs.'. The group of commands has global parameter '--help -h' which means 'Show this help message and exit.'. The group of commands has global parameter '--only-show-errors' which means 'Only show errors, suppressing warnings.'. The group of commands has global parameter '--output -o' which means 'Output format.'. The group of commands has global parameter '--query' which means 'JMESPath query string. See <a href="http://jmespath.org/">http://jmespath.org/</a> for more information and examples.'. The group of commands has global parameter '--subscription' which means 'Name or ID of subscription. You can configure the default subscription using `az account set -s NAME_OR_ID`.'. The group of commands has global parameter '--verbose' which means 'Increase logging verbosity. Use --debug for full debug logs.'. This group contains a child command 'az_networkfabric_externalnetwork_update'.The syntax is: az networkfabric externalnetwork update [--annotation]
                                        [--export-route-policy]
                                        [--export-route-policy-id]
                                        [--ids]
                                        [--import-route-policy]
                                        [--import-route-policy-id]
                                        [--l3-isolation-domain-name]
                                        [--nni-id]
                                        [--no-wait {0, 1, f, false, n, no, t, true, y, yes}]
                                        [--option-a-properties]
                                        [--option-b-properties]
                                        [--peering-option {optiona, optionb}]
                                        [--resource-group]
                                        [--resource-name]
                                        [--subscription]. The 1th example of the child command would be to use it to 'update the external network with option b properties', the syntax is: az networkfabric externalnetwork update --resource-group "example-rg" --l3domain "example-l3domain" --resource-name "example-externalNetwork" --peering-option "OptionB" --option-b-properties "{routeTargets:{exportIpv4RouteTargets:['65046:10039'],exportIpv6RouteTargets:['65046:10039'],importIpv4RouteTargets:['65046:10039'],importIpv6RouteTargets:['65046:10039']}}" --import-route-policy "{importIpv4RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy',importIpv6RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy'}" --export-route-policy "{exportIpv4RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy',exportIpv6RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy'}". The 2th example of the child command would be to use it to 'update the external network with option a properties', the syntax is: az networkfabric externalnetwork update --resource-group "example-rg" --l3domain "example-l3domain" --resource-name "example-externalNetwork" --peering-option "OptionA" --nni-id "/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourcegroups/example-rg/providers/microsoft.managednetworkfabric/networkfabrics/example-fabric/networkToNetworkInterconnects/example-nni" --option-a-properties "{peerASN:65234,vlanId:501,mtu:1500,primaryIpv4Prefix:'172.23.1.0/31',secondaryIpv4Prefix:'172.23.1.2/31',bfdConfiguration:{multiplier:5,intervalInMilliSeconds:300}}" --import-route-policy "{importIpv4RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy',importIpv6RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy'}" --export-route-policy "{exportIpv4RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy',exportIpv6RoutePolicyId:'/subscriptions/xxxxx-xxxx-xxxx-xxxx-xxxxx/resourceGroups/example-rg/providers/microsoft.managednetworkfabric/routePolicies/example-routepolicy'}". The 3th example of the child command would be to use it to 'help text for sub parameters under the specific parent can be viewed by using the shorthand syntax       see https   github com azure azure cli tree dev doc shorthand_syntax md for more about shorthand syntax', the syntax is: az networkfabric externalnetwork update --option-a-properties "??". The parameter '--annotation' is optional. description for underlying resource.. The parameter '--export-route-policy' is optional. export route policy either ipv4 or ipv6.  support shorthand-syntax, json-file and yaml-file. try "??" to show more.. The parameter '--export-route-policy-id' is optional. arm resource id of the routepolicy. this is used for the backward compatibility.. The parameter '--ids' is optional. one or more resource ids (space-delimited). it should be a complete resource id containing all information of 'resource id' arguments. you should provide either --ids or other 'resource id' arguments.. The parameter '--import-route-policy' is optional. import route policy either ipv4 or ipv6.  support shorthand-syntax, json-file and yaml-file. try "??" to show more.. The parameter '--import-route-policy-id' is optional. arm resource id of the routepolicy. this is used for the backward compatibility.. The parameter '--l3-isolation-domain-name --l3domain' is optional. name of the l3 isolation domain.. The parameter '--nni-id' is optional. arm resource id of the networktonetworkinterconnectid of the externalnetwork resource.. The parameter '--no-wait' is optional. do not wait for the long-running operation to finish.. The parameter '--option-a-properties' is optional. option a properties object.  support shorthand-syntax, json-file and yaml-file. try "??" to show more.. The parameter '--option-b-properties' is optional. option b properties object.  support shorthand-syntax, json-file and yaml-file. try "??" to show more.. The parameter '--peering-option' is optional. peering option list.. The parameter '--resource-group -g' is optional. name of resource group. you can configure the default group using `az configure --defaults group=<name>`.. The parameter '--resource-name' is optional. name of the external network.. The parameter '--subscription' is optional. name or id of subscription. you can configure the default subscription using `az account set -s name_or_id`.. 