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这样的模块能不能减缓DDOS.,SYN等主动连接的攻击呢>????
只能用减缓这个词...毕竟如果对的流量大于你的带宽了...什么也是没有办法的...
希望大家一起讨论........
recent
Allows you to dynamically create a list of IP addresses and then match against that list in a few different ways.
For example, you can create a "badguy" list out of people attempting to connect to port 139 on your firewall and then DROP all future packets from them without considering them.
--set, --rcheck, --update and --remove are mutually exclusive.
--name name
Specify the list to use for the commands. If no name is given then DEFAULT will be used.
[!] --set
This will add the source address of the packet to the list. If the source address is already in the list, this will update the existing entry. This will always return success (or failure if ! is passed in).
--rsource
Match/save the source address of each packet in the recent list table. This is the default.
--rdest
Match/save the destination address of each packet in the recent list table.
[!] --rcheck
Check if the source address of the packet is currently in the list.
[!] --update
Like --rcheck, except it will update the "last seen" timestamp if it matches.
[!] --remove
Check if the source address of the packet is currently in the list and if so that address will be removed from the list and the rule will return true. If the address is not found, false is returned.
--seconds seconds
This option must be used in conjunction with one of --rcheck or --update. When used, this will narrow the match to only happen when the address is in the list and was seen within the last given number of seconds.
--hitcount hits
This option must be used in conjunction with one of --rcheck or --update. When used, this will narrow the match to only happen when the address is in the list and packets had been received greater than or equal to the given value. This option may be used along with --seconds to create an even narrower match requiring a certain number of hits within a specific time frame. The maximum value for the hitcount parameter is given by the "ip_pkt_list_tot" parameter of the xt_recent kernel module. Exceeding this value on the command line will cause the rule to be rejected.
--rttl
This option may only be used in conjunction with one of --rcheck or --update. When used, this will narrow the match to only happen when the address is in the list and the TTL of the current packet matches that of the packet which hit the --set rule. This may be useful if you have problems with people faking their source address in order to DoS you via this module by disallowing others access to your site by sending bogus packets to you.
Examples:
iptables -A FORWARD -m recent --name badguy --rcheck --seconds 60 -j DROP
iptables -A FORWARD -p tcp -i eth0 --dport 139 -m recent --name badguy --set -j DROP |
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