Configure Transit Routing Using the GUI

To create the tenant and VRF, on the menu bar, choose Tenants > Add Tenant and in the Create Tenant dialog box, perform the following tasks:

1. In the Name field, enter the tenant name.
2. In the VRF Name field, enter the VRF name.
3. Click Submit .

   Note

   After this step, perform the steps twice to create two L3Outs in the same tenant and VRF for transit routing.

To start creating the L3Out, on the Navigation pane, expand Tenant and Networking , then right-click L3Outs and choose Create L3Out .

Enter the necessary information in the Identity window of the Create L3Out wizard.

1. In the Name field, enter a name for the L3Out.
2. From the VRF drop-down list, choose the VRF.
3. From the L3 Domain drop-down list, choose the external routed domain that you previously created.
4. In the area with the routing protocol check boxes, check the desired protocols (BGP, OSPF, or EIGRP).

   For the example in this chapter, choose BGP and OSPF .

   Depending on the protocols you choose, enter the properties that must be set.

5. Enter the OSPF details, if you enabled OSPF.

   For the example in this chapter, use the OSPF area 0 and type Regular area .

6. Click Next to move to the Nodes and Interfaces window.

Enter the necessary information in the Nodes and Interfaces window of the Create L3Out wizard.

1. Determine if you want to use the default naming convention.

   In the Use Defaults field, check if you want to use the default node profile name and interface profile names:

   • The default node profile name is L3Out-name _nodeProfile , where L3Out-name is the name that you entered in the Name field in the Identity page.

   • The default interface profile name is L3Out-name _interfaceProfile , where L3Out-name is the name that you entered in the Name field in the Identity page.

2. In the Interface Types area, make the necessary selections in the Layer 3 and Layer 2 fields.

   The options are:

   • Layer 3:

     • Routed : Select this option to configure a Layer 3 route to the port channels.

       When selecting this option, the Layer 3 route can be to either physical ports or direct port channels, which are selected in the Layer 2 field in this page.

     • Routed Sub : Select this option to configure a Layer 3 sub-interface route to the port channels.

       When selecting this option, the Layer 3 sub-interface route can be to either physical ports or direct port channels, which are selected in the Layer 2 field in this page.

     • SVI : Select this option to configure a Switch Virtual Interface (SVI), which is used to provide connectivity between the ACI leaf switch and a router.

       SVI can have members that are physical ports, direct port channels, or virtual port channels, which are selected in the Layer 2 field in this page.

     • Floating SVI : Select this option to configure floating L3Out.

       Floating L3Out enables you to configure an L3Out that allows a virtual router to move from under one leaf switch to another. The feature saves you from having to configure multiple L3Out interfaces to maintain routing when VMs move from one host to another.

   • Layer 2: (not available if you select Virtual SVI in the Layer 3 area)

     • Port

     • Virtual Port Channel (available if you select SVI in the Layer 3 area)

     • Direct Port Channel

3. From the Node ID field drop-down menu, choose the node for the L3Out.

   For the topology in these examples, use node 103 .

4. In the Router ID field, enter the router ID (IPv4 or IPv6 address for the router that is connected to the L3Out).
5. Optional: You can configure another IP address for a loopback address, if necessary.

   The Loopback Address field is automatically populated with the same entry that you provide in the Router ID field. This is the equivalent of the Use Router ID for Loopback Address option in previous builds. Enter a different IP address for a loopback address, if you don't want to use route ID for the loopback address, or leave this field empty if you do not want to use the router ID for the loopback address.

6. Enter necessary additional information in the Nodes and Interfaces window.

   The fields shown in this window varies, depending on the options that you select in the Layer 3 and Layer 2 areas.

7. When you have entered the remaining additional information in the Nodes and Interfaces window, click Next .

   The Protocols window appears.

Enter the necessary information in the Protocols window of the Create L3Out wizard.

1. In the BGP Loopback Policies and BGP Interface Policies areas, enter the following information:

   • Peer Address : Enter the peer IP address

   • EBGP Multihop TTL : Enter the connection time to live (TTL). The range is from 1 to 255 hops; if zero, no TTL is specified. The default is zero.

   • Remote ASN : Enter a number that uniquely identifies the neighbor autonomous system. The Autonomous System Number can be in 4-byte as plain format from 1 to 4294967295.

     Note

     ACI does not support asdot or asdot+ format AS numbers.

2. In the OSPF area, choose the default OSPF policy, a previously created OSPF policy, or Create OSPF Interface Policy .
3. Click Next .

   The External EPG window appears.

Enter the necessary information in the External EPG window of the Create L3Out wizard.

1. In the Name field, enter a name for the external network.
2. In the Provided Contract field, enter the name of a provided contract.
3. In the Consumed Contract field, enter the name of a consumed contract.
4. In the Default EPG for all external networks field, uncheck if you don’t want to advertise all the transit routes out of this L3Out connection.

   The Subnets area appears if you uncheck this box. Specify the desired subnets and controls as described in the following steps.

5. Click the + icon to expand Subnet , then perform the following actions in the Create Subnet dialog box.
6. In the IP address field, enter the IP address and network mask for the external network.
7. In the Name field, enter the name of the subnet.
8. In the Scope field, check the appropriate check boxes to control the import and export of prefixes for the L3Out.

   Note

   For more information about the scope options, see the online help for this Create Subnet panel.

9. Optional: Click the check box for Export Route Control Subnet .

   The BGP Route Summarization Policy field now becomes available.

10. In the BGP Route Summarization Policy field, from the drop-down list, choose an existing route summarization policy or create a new one as desired.

    The type of route summarization policy depends on the routing protocols that are enabled for the L3Out.

11. Click OK when you have completed the necessary configurations in the Create Subnet window.
12. Optional: Repeat to add more subnets.
13. Click Finish to complete the necessary configurations in the Create L3Out wizard.

Navigate to the L3Out that you just created, then right-click on the L3Out and select Create Route map for import and export route control .

In the Create Route map for import and export route control window, perform the following actions:

1. In the Name field, enter the route map name.
2. Choose the Type .

   For this example, leave the default, Match Prefix AND Routing Policy .

3. Click the + icon to expand Contexts and create a route context for the route map.
4. Enter the order and name of the profile context.
5. Choose Deny or Permit for the action to be performed in this context.
6. Optional: In the Set Rule field, choose Create Set Rules for a Route Map .

   Enter the name for the set rules, click the objects to be used in the rules, and click Finish .

7. In the Match Rule field, choose Create Match Rule for a Route Map .
8. Enter the name for the match rule and enter the Match Regex Community Terms , Match Community Terms , or Match Prefix to match in the rule.
9. When you have finished filling in the fields in the Create Match Rule window, click Submit .
10. In the Create Route Control Context dialog box, click OK .
11. In the Create Route map for import and export route control dialog box, click Submit .

In the Navigation pane, expand L3Outs > L3Out_name > External EPGs > externalEPG_name , and perform the following actions:

1. Click the + icon to expand Route Control Profile .
2. In the Name field, choose the route control profile that you previously created from the drop-down list.
3. In the Direction field, choose Route Export Policy .
4. Click Update .

Navigate to the L3Out that you just created, then right-click on the L3Out and select Create Route map for import and export route control .

In the Create Route map for import and export route control window, perform the following actions.

1. In the Name field, choose default-import .
2. In the Type field, you must select Match Routing Policy Only
3. In the Create Route map for import and export route control dialog box, click Submit .

To enable communications between the EPGs consuming the L3Out, create at least one filter and contract, using the following steps:

1. In the Navigation pane, under the tenant consuming the L3Out, expand Contracts .
2. Right-click Filters and choose Create Filter .
3. In the Name field, enter a filter name.

   A filter is essentially an Access Control List (ACL).

4. Click the + icon to expand Entries , and add a filter entry.
5. Add the Entry details.

   For example, for a simple web filter, set criteria such as the following:

   • EtherType — IP

   • IP Protocol — tcp

   • Destination Port Range From — Unspecified

   • Destination Port Range To to https

6. Click Update .
7. In the Create Filter dialog box, click Submit .

To add a contract, use the following steps:

1. Under Contracts , right-click Standard and choose Create Contract .
2. Enter the name of the contract.
3. Click the + icon to expand Subjects to add a subject to the contract.
4. Enter a name for the subject.
5. Click the + icon to expand Filters and choose the filter that you previously created from the drop-down list.
6. Click Update .
7. In the Create Contract Subject dialog box, click OK .
8. In the Create Contract dialog box, click Submit .

Associate the EPGs for the L3Out with the contract, with the following steps:

1. To associate the contract to the L3 external EPG, as the provider, under the tenant, click Networking , expand L3Outs , and expand the L3Out.
2. Expand External EPGs , click the L3 external EPG, and click the Contracts tab.
3. Click the the + icon to expand Provided Contracts .

   For the second L3 external EPG, click the + icon to expand Consumed Contracts.

4. In the Name field, choose the contract that you previously created from the list.
5. Click Update .
6. Click Submit .