Limit getting reset

Tomas Edwardsson tommi@tommi.org
Thu, 26 Jul 2001 16:58:32 +0000


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Hi

I'm having problems with the limit module. What I have been doing is
setting "--limit 1/day --limit-burst 1 --syn" so that only one connection
should get through ideally. This works completely.

The real problem is that I set a limit, then someone connects through it
and it works. But later I have to set a new rule for a different user
and it goes in, but the limit for the rule I set before is reset. I
have a comprehensive demo on how this happens in the attached file
including my version of linux (2.4.7) and iptables (1.2.2). Any help
is greatly appreciated. Thanks.

- Tomas Edwardsson
- Linux/Unix Support
- Opin Kerfi
- Iceland

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[root@fw-node31 iptables]# iptables -L -vn
Chain INPUT (policy ACCEPT 63 packets, 6422 bytes)
 pkts bytes target     prot opt in     out     source               destination         
   54  3398 ONE_TIME   all  --  *      *       0.0.0.0/0            0.0.0.0/0          
    4   240 REJECT     tcp  --  *      *       127.0.0.1            127.0.0.1          state INVALID,NEW tcp dpt:25 reject-with icmp-port-unreachable 
    0     0 LOG        all  --  eth0   *      !10.0.0.0/8           10.193.2.28        state INVALID,NEW LOG flags 0 level 4 prefix `FF Rejected ' 
    0     0 REJECT     all  --  eth0   *      !10.0.0.0/8           10.193.2.28        state INVALID,NEW reject-with icmp-proto-unreachable 

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 55 packets, 3606 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain ONE_TIME (1 references)
 pkts bytes target     prot opt in     out     source               destination         
[root@fw-node31 iptables]# telnet localhost 25
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
[root@fw-node31 iptables]# iptables -A ONE_TIME -m limit -j ACCEPT -p tcp --syn --limit 1/day --limit-burst 1 -s 127.0.0.1 -d 127.0.0.1 --destination-port 25
[root@fw-node31 iptables]# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 fw-node31.tommi.org ESMTP Sendmail 8.11.2/8.11.2; Thu, 26 Jul 2001 16:46:05 GMT
quit
221 2.0.0 fw-node31.tommi.org closing connection
Connection closed by foreign host.
[root@fw-node31 iptables]# telnet localhost 25
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
[root@fw-node31 iptables]# iptables -A ONE_TIME -m limit -j ACCEPT -p tcp --syn --limit 1/day --limit-burst 1 -s 127.0.0.1 -d 127.0.0.1 --destination-port 26
[root@fw-node31 iptables]# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 fw-node31.tommi.org ESMTP Sendmail 8.11.2/8.11.2; Thu, 26 Jul 2001 16:46:19 GMT
quit
221 2.0.0 fw-node31.tommi.org closing connection
Connection closed by foreign host.
[root@fw-node31 iptables]# iptables -L -vn
Chain INPUT (policy ACCEPT 111 packets, 9460 bytes)
 pkts bytes target     prot opt in     out     source               destination         
  108  6796 ONE_TIME   all  --  *      *       0.0.0.0/0            0.0.0.0/0          
    8   480 REJECT     tcp  --  *      *       127.0.0.1            127.0.0.1          state INVALID,NEW tcp dpt:25 reject-with icmp-port-unreachable 
    0     0 LOG        all  --  eth0   *      !10.0.0.0/8           10.193.2.28        state INVALID,NEW LOG flags 0 level 4 prefix `FF Rejected ' 
    0     0 REJECT     all  --  eth0   *      !10.0.0.0/8           10.193.2.28        state INVALID,NEW reject-with icmp-proto-unreachable 

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 108 packets, 7004 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain ONE_TIME (1 references)
 pkts bytes target     prot opt in     out     source               destination         
    2   120 ACCEPT     tcp  --  *      *       127.0.0.1            127.0.0.1          limit: avg 1/day burst 1 tcp dpt:25 flags:0x16/0x02 
    0     0 ACCEPT     tcp  --  *      *       127.0.0.1            127.0.0.1          limit: avg 1/day burst 1 tcp dpt:26 flags:0x16/0x02 
[root@fw-node31 iptables]# uname -a
Linux fw-node31.tommi.org 2.4.7 #2 Fim Júl 26 16:03:05 GMT 2001 i686 unknown
[root@fw-node31 iptables]# iptables --version
iptables v1.2.2
[root@fw-node31 iptables]#

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