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Route Policy in Network Fabric

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Route policies provide Operators the capability to allow or deny routes in regards to Layer 3 isolation domains in Network Fabric.

With route policies, routes are tagged with certain attributes via community values and extended community values when they're distributed via Border Gateway Protocol (BGP). Similarly, on the BGP listener side, route policies can be authored to discard/allow routes based on community values and extended community value attributes.

Route policies enable operators to control routes learnt/distributed via BGP. Each route policy is modeled as a separate top level Azure Resource Manager (ARM) resource under Microsoft.managednetworkfabric. Operators can create, read, and delete route policy resources. The operator creates a route policy ARM resource and then sets the ID in the L3 isolation domain at the required enforcement point. A route policy can only be applied at a single enforcement point. A route policy can't be applied at multiple enforcement points.

In a network fabric, route policies can be enforced at the following endpoints of a layer 3 isolation domain:

External networks (option A and option B):

For egress, set the exportRoutePolicyId property of the external network resource to the route policy resource ID created for egress direction. Set the importRoutePolicyId property of the external network resource to the route policy resource ID created for ingress direction.

Internal networks:

For egress, set the exportRoutePolicyId property of the internal network resource to the route policy resource ID created for egress direction. Set the importRoutePolicyId property of the internal network resource to the route policy resource ID created for ingress direction.

Connected subnets across all internal networks:

For egress, set the connectedSubnetRoutePolicy property of the L3 isolation domain to the route policy resource ID created for egress direction.

Conditions and actions of a route policy

The following combinations of conditions can be specified:

  • IP Prefix
  • IP community
  • Extended community list

Actions

The following actions can be specified when there's a match of conditions:

  • Discard the route
  • Permit the route and apply one of the following specific actions
  • Add/Remove specified community values and extended community values
  • Overwrite specified community values and extended community values

IP prefix

IP prefixes are used in specifying match conditions for route policies. An IP prefix resource allows operators to manipulate routes based on the IP prefix (IPv4 and IPv6). The IP prefixes enable operators to drop certain prefixes from being propagated up-stream/down-stream or tag them with specific community or extended community values. The operator must create an ARM resource of the type IP-Prefix by providing a list of prefixes with sequence numbers and action.

The prefixes in the list are processed in ascending order and the matching process stops after the first match. If the first match condition is "deny", the route is dropped and isn't propagated further. If the first match condition is "allow", further matching is aborted and the route is handled based on the action part of the route policies.

IP prefixes specify only the match conditions of route policies. They don't specify the action part of route policies.

Parameters for IP prefix

Parameter Description Example Required
resource-group Use an appropriate resource group name specifically for the IP prefix of your choice ResourceGroupName True
resource-name Resource Name of the IP prefix ipprefixv4-1204-cn1 True
location Azure region used during NFC creation eastus True
action Action to be taken for the prefix – Permit Deny or Permit True
sequenceNumber Sequence in which the prefixes are processed. Prefix lists are evaluated starting with the lowest sequence number and continue down the list until a match is made. Once a match is made, the permit or deny statement is applied to that network and the rest of the list is ignored 100 True
networkPrefix Network Prefix specifying IPv4/IPv6 packets to be permitted or denied. 1.1.1.0/24 True
condition Specified prefix list bounds- EqualTo | GreaterThanOrEqualTo | LesserThanOrEqualTo EqualTo
subnetMaskLength SubnetMaskLength specifies the minimum networkPrefix length to be matched. Required when condition is specified. 32

Create IP Prefix

This command creates an IP prefix resource with IPv4 prefix rules:

az networkfabric ipprefix create \
--resource-group "ResourceGroupName" \
--resource-name "ipprefixv4-1204-cn1" \
--location "eastus" \
--ip-prefix-rules '[{"action": "Permit", "sequenceNumber": 10, "networkPrefix": "10.10.10.0/28", "condition": "EqualTo", "subnetMaskLength": 28}, {"action": "Permit", "sequenceNumber": 12, "networkPrefix": "20.20.20.0/24", "condition": "EqualTo", "subnetMaskLength": 24}]'

Expected output:

{
  "annotation": null,
  "id": "/subscriptions/xxxx-xxxx/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv4-1204-cn1",
  "ipPrefixRules": [
    {
      "action": "Permit",
      "condition": "GreaterThanOrEqualTo",
      "networkPrefix": "10.10.10.0/28",
      "sequenceNumber": 10,
      "subnetMaskLength": 28
    }
  ],
  "location": "eastus",
  "name": " ipprefixv4-1204-cn1",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "systemData": {
    "createdAt": "2023-XX-XXT09:34:19.095543+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT09:34:19.095543+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/ipprefixes"
}

This command creates an IP prefix resource with IPv6 prefix rules,

az networkfabric ipprefix create \
--resource-group "ResourceGroupName" \
--resource-name "ipprefixv6-2701-cn1" \
--location "eastus" \
--ip-prefix-rules '[{"action": "Permit", "sequenceNumber": 10, "networkPrefix": "fda0:d59c:da12:20::/64", "condition": "GreaterThanOrEqualTo", "subnetMaskLength": 68}]'

Expected Output

{
  "annotation": null,
  "id": "/subscriptions/xxxx-xxxx/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-cn1",
  "ipPrefixRules": [
    {
      "action": "Permit",
      "condition": "GreaterThanOrEqualTo",
      "networkPrefix": "fda0:d59c:da12:20::/64",
      "sequenceNumber": 10,
      "subnetMaskLength": 68
    }
  ],
  "location": "eastus",
  "name": "ipprefixv6-2701-cn1",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "systemData": {
    "createdAt": "2023-XX-XXT09:34:19.095543+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT09:34:19.095543+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/ipprefixes"
}

IP Community

IP community resource allows operators to manipulate routes based on Community values tagged to routes. This community resource enables operators to specify conditions and actions for adding/removing routes as they're propagated up-stream/down-stream or tag them with specific community values. The operator must create an ARM resource of the type IP-Community. The operator specifies conditions and actions for adding/removing routes as they're propagated up-stream/down-stream or tags them with specific community values.

Parameters for IP community

Parameter Description Example Required
resource-group Use an appropriate resource group name specifically for your IP prefix ResourceGroupName True
resource-name Resource Name of the IP-Prefix ipprefixv4-1204-cn1 True
location AzON Azure Region used during NFC Creation eastus True
action Action to be taken for the IP community – Permit Deny or Permit True
wellKnownCommunities Supported well known community list.Internet - Advertise routes to internet community. LocalAS - Advertise routes to only localAS peers. NoAdvertise - Don't advertise routes to any peer. NoExport - Don't export to next AS. GShut - Graceful Shutdown (GSHUT) withdraw routes before terminating BGP connection LocalAS True
communityMembers List the communityMembers of the IP community. The expected formats are "AA:nn" >> example "65535:65535", <integer32> >> example 4294967040. The possible values of "AA:nn" is 0-65535, and of <integer32> 1-4294967040. 65535:65535 True

Note

Either wellKnownCommunities or communityMembers parameter has to be passed for creating an IP community resource.

Create IP community

This command creates an IP community resource:

az networkfabric ipcommunity create \
--resource-group "ResourceGroupName" \
--resource-name "ipcommunity-2701" \
--location "eastus" \
--action "Permit" \
--well-known-communities "Internet" "LocalAS" "GShut" \
--community-members "65500:12701"

Expected output:

{
  "action": "Permit",
  "annotation": null,
  "communityMembers": [
    "65500:12701"
  ],
  "id": "/subscriptions/9531faa8-8c39-4165-b033-48697fe943db/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-2701",
  "location": "eastus",
  "name": "ipcommunity-2701",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "systemData": {
    "createdAt": "2023-XX-XXT09:48:15.472935+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT09:48:15.472935+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/ipcommunities",
  "wellKnownCommunities": [
    "Internet",
    "LocalAS",
    "GShut"
  ]
}

Show IP community

This command displays an IP community resource:

az networkfabric ipcommunity show --resource-group "ResourceGroupName" --resource-name "ipcommunity-2701"

Expected output:

{
  "action": "Permit",
  "annotation": null,
  "communityMembers": [
    "65500:12701"
  ],
  "id": "/subscriptions/9531faa8-8c39-4165-b033-48697fe943db/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-2701",
  "location": "eastus",
  "name": "ipcommunity-2701",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "systemData": {
    "createdAt": "2023-XX-XXT09:48:15.472935+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT09:48:15.472935+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/ipcommunities",
  "wellKnownCommunities": [
    "Internet",
    "LocalAS",
    "GShut"
  ]
}

IP extended community

The IPExtendedCommunityresource allows operators to manipulate routes based on route targets. Operators use it to specify conditions and actions for adding/removing routes as they're propagated up-stream/down-stream or tag them with specific extended community values. The operator must create an ARM resource of the type IPExtendedCommunityList by providing a list of community values and specific properties. ExtendedCommunityLists are used in specifying match conditions and the action properties for route policies.

Parameters for IP extended community

Parameter Description Example Required
resource-group Use an appropriate resource group name specifically for your IP prefix ResourceGroupName True
resource-name Resource Name of the ipPrefix ipprefixv4-1204-cn1 True
location AzON Azure Region used during NFC Creation eastus True
action Action to be taken for the IP extended community – Permit Deny or Permit True
routeTargets Route Target List. The expected formats are "ASN(plain):nn" >> example "4294967294:50", "ASN.ASN:nn" >> example "65533.65333:40", "IP-address:nn" >> example "10.10.10.10:65535". The possible values of "nn" are within "0-65535" range, and "ASN(plain)" within "0-4294967295" range. "1234:5678" True

Create IP extended community

This command creates an IP extended community resource:

az networkfabric ipextendedcommunity create \
--resource-group "ResourceGroupName" \
--resource-name "ipextcommunity-2701" \
--location "eastus"  \
--action "Permit" \
--route-targets "65046:45678"

Expected output:

{
  "action": "Permit",
  "annotation": null,
  "id": "/subscriptions/9531faa8-8c39-4165-b033-48697fe943db/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipExtendedCommunities/ipextcommunity-2701",
  "location": "eastus",
  "name": "ipextcommunity-2701",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "routeTargets": [
    "65046:45678"
  ],
  "systemData": {
    "createdAt": "2023-XX-XXT09:52:30.385929+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT09:52:30.385929+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/ipextendedcommunities"
}

Show IP extended community

This command displays an IP extended community resource:

az networkfabric ipextendedcommunity show --resource-group "ResourceGroupName" --resource-name "ipextcommunity-2701"

Expected output:

{
  "action": "Permit",
  "annotation": null,
  "id": "/subscriptions/9531faa8-8c39-4165-b033-48697fe943db/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipExtendedCommunities/ipextcommunity-2701",
  "location": "eastus",
  "name": "ipextcommunity-2701",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "routeTargets": [
    "65046:45678"
  ],
  "systemData": {
    "createdAt": "2023-XX-XXT09:52:30.385929+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT09:52:30.385929+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/ipextendedcommunities"
}

Route policy

Route policy resource enables an operator to specify conditions and actions based on IP prefixes, IP community list and IP extended community lists. Each route policy consists of multiple statements. Each statement consists of a sequence number, conditions, and actions. The conditions can be combinations of IP prefixes, IP communities, and IP extended communities and are applied in ascending order of sequence numbers. The action corresponding to the first matched condition is executed. If the conditions that matched has deny as action, the route is discarded and no further processing takes place. If the action in the Route policy corresponding to the matched condition is "Permit", the following combinations of actions are allowed:

  • Updating local preference
  • Add/delete or Set of IpCommunityLists
  • Add/delete or Set of IpExtendedCommunityLists

Parameters for Route policy

Parameter Description Example Required
resource-group Use an appropriate resource group name specifically for your IP prefix ResourceGroupName True
resource-name Resource Name of the IP-Prefix ipprefixv4-1204-cn1 True
location AzON Azure Region used during NFC Creation eastus True
statements List of one or more route Policy statements True
sequenceNumber Sequence in which route policy statements are processed. Statements are evaluated starting with the lowest sequence number and continue down the list until a match condition is met. Once a match is made, the action is applied and the rest of the list is ignored 1 True
condition Route policy condition properties. That contains a list of IP community ARM IDs or ipExtendedCommmunicty ARM IDs or ipPrefix ARM ID. One of the three(ipCommunityIds, ipCommunityIds, ipPrefixId) is required in a condition. If more than one is specified, the condition is matched if any one of the resources has a match. 1234:5678 True
ipCommunityIds List of IP community resource IDs False
ipExtendedCommunityIds List of IPExtendedCommunity resource IDs False
ipPrefixId Arm Resource ID of IpPrefix False
action Route policy action properties. This property describes the action to be performed if there's a match of the condition in the statement. At least one of localPreference, ipCommunityProperties, or ipExtendedCommunityProperties needs to be enabled Permit True
localPreference Local preference to be set as part of action 10 False
ipCommunityProperties Details of IP communities that need to be added, removed, or set as part of action False
add Applicable when the action is to add IP communities or IP extended communities
delete Applicable when the action is to delete IP communities or IP extended communities
set Applicable when the action is to set IP communities or IP extended communities
ipCommunityIds IP community ARM resource Ids that need to be added or deleted or set
ipExtendedCommunityProperties Details of IP Extended communities that need to be added, removed, or set as part of action
ipExtendedCommunityIDs IP extended community ARM resource Ids that need to be added or deleted or set

Create route policy

This command creates route policies:

az networkfabric routepolicy create \
--resource-group "ResourceGroupName"  \
--resource-name "rcf-Fab3-l3domain-v6-connsubnet-ext-policy" \
--location "eastus" \
--statements '[ \{"sequenceNumber": 10, "condition":{"ipPrefixId": "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-staticsubnet"}, \
 "action": {"actionType": "Permit", "ipCommunityProperties": {"set": \
   {"ipCommunityIds": ["/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-2701-staticsubnet"]}}}}, \
 {"sequenceNumber": 30, "condition":{"ipPrefixId": "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-connsubnet"},  \
 "action": {"actionType": "Permit", "ipCommunityProperties": {"set":  \
 {"ipCommunityIds": ["/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-connsubnet-2701"]}}}},\
]'

Expected output:

{
  "annotation": null,
  "id": "/subscriptions/9531faa8-8c39-4165-b033-48697fe943db/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/routePolicies/rcf-Fab3-l3domain-v6-connsubnet-ext-policy",
  "location": "eastus",
  "name": "rcf-Fab3-l3domain-v6-connsubnet-ext-policy",
  "provisioningState": "Accepted",
  "resourceGroup": "ResourceGroupName",
  "statements": [
    {
      "action": {
        "actionType": "Permit",
        "ipCommunityProperties": {
          "add": null,
          "delete": null,
          "set": {
            "ipCommunityIds": [
              "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-2701-staticsubnet"
            ]
          }
        },
        "ipExtendedCommunityProperties": null,
        "localPreference": null
      },
      "annotation": null,
      "condition": {
        "ipCommunityIds": null,
        "ipExtendedCommunityIds": null,
        "ipPrefixId": "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-staticsubnet"
      },
      "sequenceNumber": 10
    },
    {
      "action": {
        "actionType": "Permit",
        "ipCommunityProperties": {
          "add": null,
          "delete": null,
          "set": {
            "ipCommunityIds": [
              "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-connsubnet-2701"
            ]
          }
        },
        "ipExtendedCommunityProperties": null,
        "localPreference": null
      },
      "annotation": null,
      "condition": {
        "ipCommunityIds": null,
        "ipExtendedCommunityIds": null,
        "ipPrefixId": "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-connsubnet"
      },
      "sequenceNumber": 30
    }
  ],
  "systemData": {
    "createdAt": "2023-XX-XXT10:10:21.123560+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT10:10:21.123560+00:00",
    "lastModifiedBy": "user@address.com",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/routepolicies"
}

Show route policy

This command displays route policies:

az networkfabric routepolicy show --resource-group "ResourceGroupName" --resource-name "rcf-Fab3-l3domain-v6-connsubnet-ext-policy"

Expected output:

{
  "annotation": null,
  "id": "/subscriptions/9531faa8-8c39-4165-b033-48697fe943db/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/routePolicies/rcf-Fab3-l3domain-v6-connsubnet-ext-policy",
  "location": "eastus",
  "name": "rcf-Fab3-l3domain-v6-connsubnet-ext-policy",
  "provisioningState": "Succeeded",
  "resourceGroup": "ResourceGroupName",
  "statements": [
    {
      "action": {
        "actionType": "Permit",
        "ipCommunityProperties": {
          "add": null,
          "delete": null,
          "set": {
            "ipCommunityIds": [
              "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-2701-staticsubnet"
            ]
          }
        },
        "ipExtendedCommunityProperties": null,
        "localPreference": null
      },
      "annotation": null,
      "condition": {
        "ipCommunityIds": null,
        "ipExtendedCommunityIds": null,
        "ipPrefixId": "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-staticsubnet"
      },
      "sequenceNumber": 10
    },
    {
      "action": {
        "actionType": "Permit",
        "ipCommunityProperties": {
          "add": null,
          "delete": null,
          "set": {
            "ipCommunityIds": [
              "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipCommunities/ipcommunity-connsubnet-2701"
            ]
          }
        },
        "ipExtendedCommunityProperties": null,
        "localPreference": null
      },
      "annotation": null,
      "condition": {
        "ipCommunityIds": null,
        "ipExtendedCommunityIds": null,
        "ipPrefixId": "/subscriptions/<subscription-id>/resourceGroups/ResourceGroupName/providers/Microsoft.ManagedNetworkFabric/ipPrefixes/ipprefixv6-2701-connsubnet"
      },
      "sequenceNumber": 30
    }
  ],
  "systemData": {
    "createdAt": "2023-XX-XXT10:10:21.123560+00:00",
    "createdBy": "user@address.com",
    "createdByType": "User",
    "lastModifiedAt": "2023-XX-XXT10:10:21.123560+00:00",
    "lastModifiedBy": "user@addresscom",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.managednetworkfabric/routepolicies"
}