RouterOS disconnection Solution

Article Title: RouterOS disconnection solution. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

I carefully read the posts posted by netizens on the Forum and think that the problem of disconnection can be solved.

The so-called cut-off: Here I define a cut-off as a phenomenon where online games are constantly playing, but webpage reading is intermittent and even cannot be opened.

Problem analysis: the principle of nat is to convert the source address to a public IP address. For TCP applications, the source IP address is also converted to a PORT. that is, the address conversion relationship of a TCP connection is ip + port. generally, the router creates a NAT connection table. So that this packet can be converted to the machine that sent the TCP request in time when the data packet is returned ...... However, generally, when nat is implemented by the router, two conditions are implied. 1) NAT consumes resources, so the number of nat connections is generally limited. Otherwise, the router will be paralyzed when a user creates a random connection with a virus. 2) nat has a certain aging time for the nat translation ing tables of tcp udp icmp protocols. Once the time reaches the time when the other party does not return data, the connection will be deleted from the ing table.

Then, the problem is analyzed, and online games constantly indicate that the interface is okay. The webpage is intermittent because there are no redundant connections. Why can online games continue? Because online games have several TCP connections. Data packets are being sent all the time, so that the NAT translation table items can be refreshed and the limited number of connections is very stable and will not be broken. Similarly, FTP downloads will not be interrupted.

Solution: When configuring nat, add a tcp rule to define connection-limit in Extra for a larger number of connections. The default value is only 100. I'm not sure whether connection-limit is for a single IP address with 100 NAT connections or a maximum of 100 NAT connections can be established for all IP addresses. This requires many friends from machines to perform experiments. But I think changing this value will solve the cut-off problem.

Ps: connection-limit is not recommended because a virus attack may paralyze the router. we recommend that you set the nat connection-limit quantity to 100 for the IP address of each client. such a solution is more perfect.