Question

4

What does this rule mean

rated 0 times [ 4] [ 0] / answers: 1 / hits: 1182 / 1 Year ago, fri, december 30, 2022, 3:15:08

When I run sudo iptables -L, I get:

Chain INPUT (policy ACCEPT)

target     prot opt source               destination

REJECT     tcp  --  anywhere             anywhere            tcp dpt:www flags:FIN,SYN,RST,ACK/SYN #conn/32 > 20 reject-with tcp-reset



Chain FORWARD (policy ACCEPT)

target     prot opt source               destination



Chain OUTPUT (policy ACCEPT)

target     prot opt source               destination

What does this mean?
I am pretty new to the whole Ubuntu world. I cannot access webmin at times, keep getting The connection has timed out error.

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eighethod

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2 Years ago

answered 1 Year ago imberst · Accepted Answer

This rule limits the number of parallel connections coming from a single IP to your webserver. In this case no more than 20 parallel connections from a single IP are allowed.

Usually rules like these are used to protect against DoS attacks.

Given a browser which opens a new connection for every image included in the HTML file you might easily exceed this limit.