Configuring an MCR
This topic describes how to edit and configure a Megaport Cloud Router (MCR) and Virtual Cross Connect (VXC). Before you begin, you need to create an MCR and configure a VXC, as described in Creating an MCR and Creating a VXC.
Editing an MCR
To edit an MCR
- Log in to the Megaport Portal and choose Services.
Select the MCR you want to edit.
You can edit any field on the MCR Configuration page, except the rate limit, which is fixed for the duration of the service.
The Initial BGP State lets you select whether newly created BGP connections are enabled or shut down by default. Select Enabled (the default) if you want any new BGP sessions you configure to be live as soon as you save the configuration. Select Shut Down if you want any new BGP sessions you configure to be left in a shut down state when you save the configuration.
For example, you might want to select the Shut Down option if you are planning to add a number of BGP sessions across your Virtual Cross Connects (VXCs) but know that you want to do some other router setup before you want them exchanging route information. When you are finished configuring your routers, you can then go into the relevant BGP sessions and enable them.
The setting you choose here just sets the default state for the new BGP session. You can override this in the MCR Connection detail screen. For details on overriding the BGP state for an individual connection, see Shutting down a BGP connection.
Editing a VXC
For each VXC connected to an MCR you can configure one or more interfaces, IP addresses, BGP connections, or static routes.
To edit a VXC interface
- Select the MCR A End or B End.
- To edit a BGP connection, click Edit.
- Configure your VXC.
The procedures will vary slightly depending on your destination type.
For details on the Advanced tab, see Configuring BGP Advanced Settings.
- Click Update.
The Border Gateway Protocol (BGP) allows dynamic route table updates from the MCR across the VXC to the port. Enable one or more BGP peers for the MCR, up to a maximum of five.
To configure BGP
On the MCR Connection detail page, click Add BGP Connection.
Specify these values:
Local IP – Select the IP address on this interface that communicates with the BGP peer. The drop-down menu is autopopulated based on the address you specified in the connection detail.
Peer IP – Specify the IP address for the BGP peer. For example, if the local IP is 220.127.116.11, the peer IP address would be 18.104.22.168.
Peer ASN – The ASN of the target routing device that will terminate the BGP connection. The ASN range is from 2 to 4294967294.
BGP Password – The shared key to authenticate the BGP peer. The shared key length is from 1 to 25 characters. The key can include any of these characters:
! @ # ? . $ % ^ & * + = -
A shared key is optional when creating the VXC, but is required to set up the BGP peering. You can add it after you create the VXC.
Click the eye icon to see the password as you type. The view persists until you click the eye icon again to hide the password.
Description – Optionally, include a description that will help identify this connection. The minimum description length is from 1 to 100 characters.
If you have entered multiple CIDR ranges, the IP addresses are available for selection.
Use a CIDR calculator to ensure that all data is valid and within range.
To edit a BGP connection
- Select the VXC and select MCR A End or MCR B End.
- Next to the connection, click Edit.
- Make your changes.
- Click Update.
For information on the BGP Advanced tab settings, see Configuring BGP Advanced Settings.
Static routes establish reachability to peers in place of BGP connections that provide dynamic routing. You configure static routes to provide connectivity to a customer device that doesn’t support BGP or to a target device that requires manually configured addressing and routes. With static routes, you need to manually update any topology changes.
An MCR supports up to ten static routes.
To add a static route
- Select the VXC and select MCR A End.
- In the MCR Connection detail page, under Static Routes, specify the IPv4 or IPv6 destination network address in CIDR notation.
- Specify the IPv4 or IPv6 address of the next-hop router. The address must be in the same subnet as the interface but it can’t match the interface IP address.
- Optionally, include any notes that will help identify this static route. The description range is from 1 to 100 characters.
- Click Next.
- Update the MCR B End, if necessary.
- Click Next.
- Click Update.
To view static routes, see Viewing Traffic Routing through the MCR Looking Glass.
Verifying the BGP configuration
The MCR Looking Glass provides single-screen visibility into the BGP configuration. For details, see Viewing Traffic Routing through MCR Looking Glass.
To view the BGP status
- In the Portal, choose Services.
- Select the VXC.
- Click MCR A End or MCR B End.
- Choose Details.
If the Services > Connection Detail page displays a status issue, verify these items:
- Select the VXC and select MCR A End or B End.
- Under BGP Connections, verify that the correct local ASN is in use for the A-End of the VXC.
- Verify that the correct peer IP address is in use.
- Verify that the correct BGP MD5 password is in use for the A-End of the VXC.
If the BGP configuration looks correct:
Make sure that a BGP peer is not blocking ingress or egress from TCP port 179 (BGP) and other relevant ephemeral ports.
Verify that a BGP peer is not advertising more than 100 prefixes to AWS. The maximum number of advertised routes to AWS is 100. The BGP session is disabled if it exceeds the prefix limit of 100 advertised routes.
Use this setting to temporarily disable the BGP session without removing it. BGP shutdown provides a way to administratively shut down a BGP connection while setting up a new route, performing maintenance, troubleshooting, and so on.
To temporarily disable a BGP connection
Log in to the Portal and choose Services.
Select the VXC and select the A-End or B-End.
After the BGP connection details, click Shut Down.
Click Yes to confirm.