Network Limits for a Dedicated Server Port

When ordering a dedicated server on your network equipment, limits are applied automatically. The limits work for both local ports and internet ports. For servers with MC-LAG, the limits work for the entire aggregated interface (bond).

Limits on the Number of MAC Addresses

By default, each dedicated server is assigned a limit of 25 MAC addresses per switch port.

If the limit on the number of MAC addresses on the server is exceeded, there may be a partial lack of connectivity between this server and the Internet or other machines on the local network.

Upon the client request in the ticket, this limit can be increased to 100 MAC addresses.

Please note that the limit above 100 MAC addresses can be set only if technically possible. Create a ticket to clarify.

Limits on Broadcast Traffic

For dedicated servers, there are limits on broadcast traffic (broadcast, unknown-unicast, and multicast) — 10 MB/s per port for each type of traffic.

All traffic that exceeds the specified limit is discarded by the network equipment.

Please note that exceeding the limit often occurs in the following cases:

• if the network exchange between virtual machines involves a large volume of multicast traffic. In particular, multicast is often used for the network protocols OSPF, RIPv2, VRRP, as well as clustering solutions, for example, Corosync;
• if traffic between servers is strictly unidirectional. In this case, the network equipment can classify it as unknown-unicast.

Blocked Ports

In order to prevent malicious network activity on the Selectel infrastructure, certain ports are blocked, including: 123 (NTP), 53 (DNS), and 25 (mail).

You can find a full list of restricted ports on our website.

Use the Nmap utility to see if a port is available on the OS side if it does not fall under these restrictions.