Troubleshooting MCR When Down or Unavailable

If your Megaport Cloud Router (MCR) is down, the root cause could be the status of your attached Ports or VXCs, the BGP configuration, or the interface settings. Step through these troubleshooting actions to isolate the issue.

Tip

You can verify MCR status from the Megaport Portal. On the Services page in the Portal, find the MCR and mouse over its icon. A message displays the status of the service. (The color of the icon also indicates the service status.)

Troubleshooting actions

Action Steps
Perform a ping test from the MCR A ping test transmits data packets to a specific IP address and either confirms or denies connectivity between IP-networked devices. In the case of confirmation, a ping test shows the latency (the response time) of the connection.
Run ping tests from MCR to the following destinations:
  • Each VXC attached to the MCR from the devices directly connected in Layer 3. For instance, if one of the MCR interfaces is set with IP address 172.16.100.2 with subnet mask 30, run the ping test from the device connected to the set with IP address 172.16.100.1.
Verify Layer 2 connectivity (ARP) Confirm that the IP address of the MCR is mapped correctly to the MAC address in the Address Resolution Protocol (ARP) table. For example, enter show ip arp. Layer 2 controls the flow of data between nodes on WAN or LAN segments, and is also responsible for detecting and possibly correcting Layer 1 errors. Layer 2 connectivity issues can affect the functionality of your VXCs, which connect to your MCR. When connecting to a Cloud Service Provider (CSP), ensure that the VLAN configuration details are correct. Use particular caution when connecting to Azure, as you will be using Q-in-Q. For additional guidance, reach out to your Account Manager and request a meeting with a Megaport Solution Architect.
Verify ACL/FW rules on your devices During some troubleshooting sessions where the circuit is up but you cannot ping between Layer 3 endpoints, there might be a firewall or ACL in between.

It is possible to set an interface to filter or ignore ICMP requests on many devices, leading to a failed ping, while other traffic may pass without problems.
It is essential to know the ping source, its destination, the path, and any intermediate devices it traverses. Megaport requires customers to provide a network diagram and the traceroute result before investigation and troubleshooting. Inaccurate information may lead to wrong troubleshooting results and inappropriate solutions.

Perform these checks before opening a ticket with Megaport support:
  • Ensure the source device is sending the ping packets by examining the egress interface/subinterface
  • Ensure the destination device is receiving the ping packets by reading the ingress interface/subinterface
  • Perform a traceroute and find the hop where the traceroute starts to time out. Examine the configuration on the hop.
On many devices, it is possible to set an interface to filter or ignore ICMP requests, leading to a failed ping, while other traffic may pass without problems.

Next steps

If the troubleshooting actions do not resolve your issue, contact support. Before contacting support for assistance, provide details of all troubleshooting steps. For example, if loops were placed, note where they were located and their direction.


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