Messages in this thread |  | | Subject | little problem with nat , resending packets to wrong destination. | From | bladi <> | Date | 07 May 2002 09:41:37 +0200 |
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Hi the last day a notice a extrange thing with my packetsniffer one host recive a packet that i request from the linux "router"
Network:
-----ppp0 modem-- [Linux router]eth0------[Honneypot]---
192.168.1.2 192.168.1.56
i have 2 rules in iptables
iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE iptables -t nat -A PREROUTING --in-interface ppp0 --protocol tcp --destination-port ! ssh --jump DNAT --to-destination 192.168.1.5
I usaly use the linux router to work and the honneypot to fun & profit.
i always exeute tcpdump -i eth0 -s 9000 -w LOGFILE on the router machine.
The last day when im making a revision of the log , i discover that in the log i could raead a "response" of an http request that i do from router linux ( i make a the request to external site over ppp connection).
|---| unfornatly i only have the snoop of the ppp0 interface.
80.34.69.xxx = external server
1) i make http request to 80.34.69.xxx server 2) i read the web contents correctly 3) aparently the kernel forward the response to 192.168.1.56 (honeypot)
#tcpdump -r JAULA6 -n 'tcp port 80 && host 80.34.69.xxx'
03:28:03.303637 80.34.69.xxx.80 > 192.168.1.56.33352: . 3888813151:3888814599(1448) ack 2877177511 win 6710 <nop,nop,timestamp 110497018 7927497> (DF) 03:28:03.304382 192.168.1.56.33352 > 80.34.69.xxx.80: R 2877177511:2877177511(0) win 0
#tcpdump -r JAULA6 -n 'tcp port 3000 && host 80.34.69.xxx'
03:17:04.803886 80.34.69.xxx.3000 > 192.168.1.56.33329: P 3209289308:3209289324(16) ack 2224478666 win 6720 <nop,nop,timestamp 110431569 7862787> (DF) 03:17:04.804585 192.168.1.56.33329 > 80.34.69.xxx.3000: R 2224478666:2224478666(0) win 0
In the 2 case the honneypot respond with rst because he dont start the conexion.
This happend rarely only 2 times in 1 day :|
Bye!
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