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Date:      Mon, 24 Mar 2008 21:24:33 +0100
From:      Henri Hennebert <hlh@restart.be>
To:        Kage <kagekonjou@gmail.com>
Cc:        freebsd-net@freebsd.org
Subject:   Re: natd port forward times out, tcpdump yields nothing
Message-ID:  <47E80E01.4060605@restart.be>
In-Reply-To: <d1556b2b0803240904n5b286a08hf5fffc6bde3fa09b@mail.gmail.com>
References:  <d1556b2b0803211239r598e66eqf2adf04662201a76@mail.gmail.com>	 <47E50936.1010405@restart.be>	 <d1556b2b0803232123w6108819dgabdd4ea1fdcf94d4@mail.gmail.com>	 <47E77E1C.7090000@restart.be> <d1556b2b0803240904n5b286a08hf5fffc6bde3fa09b@mail.gmail.com>

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Kage wrote:
> Still not working, but I DO have natd aliasing properly.  Here's my
> natd output (remember which IP is mine, the IRC jail, and the example
> round-robin IP):
> 
> [root@nub /etc]# natd -f /etc/natd.conf
> In  {default}[TCP]  [TCP] 72.65.73.23:2897 -> 207.210.114.45:6667 aliased to
>            [TCP] 72.65.73.23:2897 -> 72.20.28.202:6667
> In  {default}[TCP]  [TCP] 72.65.73.23:2897 -> 207.210.114.45:6667 aliased to
>            [TCP] 72.65.73.23:2897 -> 72.20.28.202:6667
> In  {default}[TCP]  [TCP] 72.65.73.23:2897 -> 207.210.114.45:6667 aliased to
>            [TCP] 72.65.73.23:2897 -> 72.20.28.202:6667
> 
> 72...23 (me) is hitting the natd on the jail IP (207...45), which is
> getting correctly aliased to 72...202 (example round-robin IP).  So it
> appears the natd is working properly.

In the client -> server direction only for now -- see bellow.

>  Here's my natd configuration as
> it exists now:
> 
> # Nub.Core NATd
> verbose
> alias_address 207.210.114.45
> log
> log_denied
> log_ipfw_denied
> pid_file /var/run/natd.pid
> 
> ### IRC Redirect Ports
> # 6667
> redirect_port tcp 72.20.28.202:6667 207.210.114.45:6667
> 
> And for more record, here's my ipfw.rules file up until the divert:
> 
> [root@nub /etc]# cat ipfw.rules
> IPF="ipfw -q add"
> ipfw -f -q flush
> 
> #loopback
> $IPF 10 allow all from any to any via lo0
> $IPF 20 deny all from any to 127.0.0.0/8
> $IPF 30 deny all from 127.0.0.0/8 to any
> $IPF 40 deny tcp from any to any frag
> 
> # statefull
> $IPF 50 check-state
> $IPF 60 allow tcp from any to any established
> $IPF 70 allow all from any to any out keep-state
> $IPF 54999 allow icmp from any to any
> 
> [snip -- Some allowed ports (port 80, 443, etc.), and some denied IPs]
> 
> # IRC (natd divert for IRC port-forwarding
> $IPF 50220 divert natd all from 72.20.28.202 6667 to 207.210.114.45 6667 via rl0
                                                                     ^^^^
The destination port must not be given (ie any destination port 
corresponding to any source port greater than 1023 for the request) - in 
this test the source port is 2897, in the next one it may be anything > 
1023. Moreover `any' in place of 207.210.114.45 would be nice to allow 
others to chat. So the rule should be:

$IPF 50220 divert natd all from 72.20.28.202 6667 to any via rl0

Henri

> $IPF 50221 divert natd all from any to 207.210.114.45 6667 via rl0
> 
> Any attempt to connect to the IRC jail IP thus far, though, still
> fails with a "connection timed out."
> 
> Thanks for your help thus far.  Any additional ideas?
> 
> On Mon, Mar 24, 2008 at 6:10 AM, Henri Hennebert <hlh@restart.be> wrote:
>> Kage wrote:
>>  > Well, no, see it's hitting natd just fine as shown by my natd verbose
>>  > logs, if you're assuming ipfw is blocking me from reaching natd.  Are
>>  > you talking about adding a firewall rule for each of my round-robin
>>  > addresses, too?
>>
>>  Yes
>>
>>
>>  >  How would that do any good?
>>
>>  All response paquet to a paquet diverted to natd must also be diverted
>>  to natd to be reverse translated. eg:
>>
>>  incoming request from client (c) to server (s) redirected to server (S)
>>
>>  c.c.c.c -> s.s.s.s   nated as c.c.c.c -> S.S.S.S
>>
>>  must have response paquetd reverse translated:
>>
>>  S.S.S.S -> c.c.c.c  nated as s.s.s.s -> c.c.c.c
>>
>>  to be a valid response to client (c).
>>
>>
>>
>>  >
>>  > On Sat, Mar 22, 2008 at 9:27 AM, Henri Hennebert <hlh@restart.be> wrote:
>>  >> Kage wrote:
>>  >>  > Hey guys,
>>  >>  >
>>  >>  >    This is a fun one that's stumped people in Freenode ##freebsd.
>>  >>  > Basically, I have this layout:
>>  >>  >
>>  >>  > irc.domain.com -> DNS A -> IRC Jail
>>  >>  >
>>  >>  > When someone connects to irc.domain.com on IRC ports (6667, 8067,
>>  >>  > etc.), it round-robins them using natd, otherwise it sends all other
>>  >>  > port requests to the IRC jail as per normal (such as port 80, which is
>>  >>  > my primary concern).  As for having it setup to have ipfw divert to
>>  >>  > natd, that's done and works, as shown by natd verbose mode:
>>  >>  >
>>  >>  > In  {default}[TCP]  [TCP] 72.65.73.23:2980 -> 207.210.114.45:6667 aliased to
>>  >>  >            [TCP] 72.65.73.23:2980 -> 207.210.114.45:6667
>>  >>  >
>>  >>  > (For reference)
>>  >>  > 207.210.114.45 = jail IP
>>  >>  > 72.20.28.202 = example target IP in the round-robin
>>  >>  > 72.65.73.23 = my IP
>>  >>  >
>>  >>  > Right now, my ipfw.rules file is as follows:
>>  >>  >
>>  >>  > [root@nub /etc]# cat ipfw.rules
>>  >>  > IPF="ipfw -q add"
>>  >>  > ipfw -f -q flush
>>  >>  >
>>  >>  > #loopback
>>  >>  > $IPF 10 allow all from any to any via lo0
>>  >>  > $IPF 20 deny all from any to 127.0.0.0/8
>>  >>  > $IPF 30 deny all from 127.0.0.0/8 to any
>>  >>  > $IPF 40 deny tcp from any to any frag
>>  >>  >
>>  >>  > # statefull
>>  >>  > $IPF 50 check-state
>>  >>  > $IPF 60 allow tcp from any to any established
>>  >>  > $IPF 70 allow all from any to any out keep-state
>>  >>  > $IPF 54999 allow icmp from any to any
>>  >>  >
>>  >>  > # Include the deny file
>>  >>  > . /etc/ipfw.deny
>>  >>  >
>>  >>  > [snip -- some allowed ports]
>>  >>  > # IRC (natd divert for IRC port-forwarding
>>  >>  > $IPF 50220 divert natd all from any to 207.210.114.45 6667 via rl0
>>  >>  > $IPF 50230 divert natd all from any to 207.210.114.45 8067 via rl0
>>  >>  > $IPF 50240 divert natd all from any to 207.210.114.45 8068 via rl0
>>  >>  > $IPF 50250 divert natd all from any to 207.210.114.45 6697 via rl0
>>  >>  > $IPF 50260 divert natd all from any to 207.210.114.45 7000 via rl0
>>  >>
>>  >>
>>  >> You must also divert the response trafic AFAIK eg:
>>  >>
>>  >>  $IPF 50220 divert natd all from 72.20.28.202 6667 to 207.210.114.45 via rl0
>>  >>
>>  >>
>>  >>
>>  >>  > # keep these two IRC ports normally open for BNC
>>  >>  > $IPF 50270 allow all from any to any 31337 in
>>  >>  > $IPF 50380 allow all from any to any 31337 out
>>  >>  > [snip -- more allowed ports]
>>  >>  > # deny and log everything
>>  >>  > $IPF 55000 deny log all from any to any
>>  >>  >
>>  >>  > -----
>>  >>  >
>>  >>  > Here's a dump of ipfw show, with some stuff cut out for space purposes
>>  >>  > (they're just denied DDoS IPs)
>>  >>  >
>>  >>  > [root@nub /etc]# ipfw show
>>  >>  > 00010  61124  16056802 allow ip from any to any via lo0
>>  >>  > 00020      0         0 deny ip from any to 127.0.0.0/8
>>  >>  > 00030      0         0 deny ip from 127.0.0.0/8 to any
>>  >>  > 00040      0         0 deny tcp from any to any frag
>>  >>  > 00050      0         0 check-state
>>  >>  > 00060 670616 455926379 allow tcp from any to any established
>>  >>  > 00070  16213  14071853 allow ip from any to any out keep-state
>>  >>  > [snip]
>>  >>  > 50220    468     22464 divert 8668 ip from any to 207.210.114.45
>>  >>  > dst-port 6667 via rl0
>>  >>  > 50230      0         0 divert 8668 ip from any to 207.210.114.45
>>  >>  > dst-port 8067 via rl0
>>  >>  > 50240      0         0 divert 8668 ip from any to 207.210.114.45
>>  >>  > dst-port 8068 via rl0
>>  >>  > 50250      0         0 divert 8668 ip from any to 207.210.114.45
>>  >>  > dst-port 6697 via rl0
>>  >>  > 50260      0         0 divert 8668 ip from any to 207.210.114.45
>>  >>  > dst-port 7000 via rl0
>>  >>  > 50270      1        60 allow ip from any to any dst-port 31337 in
>>  >>  > 54999     66      3991 allow icmp from any to any
>>  >>  > 55000   4364    343609 deny log logamount 100 ip from any to any
>>  >>  > 65535     29      4176 allow ip from any to any
>>  >>  >
>>  >>  > My natd.conf is as follows:
>>  >>  >
>>  >>  > [root@nub /etc]# cat natd.conf
>>  >>  > # Nub.Core NATd
>>  >>  > verbose
>>  >>  > alias_address 207.210.114.45
>>  >>  > log
>>  >>  > log_denied
>>  >>  > log_ipfw_denied
>>  >>  > pid_file /var/run/natd.pid
>>  >>  >
>>  >>  >
>>  >>  > ### IRC Redirect Ports
>>  >>  > # 6667
>>  >>
>>  >>
>>  >> If I understand man natd
>>  >>
>>  >>
>>  >>> redirect_port tcp 72.20.28.202:6667 207.210.114.45:6667 207.210.114.45:6667
>>  >>                                                            ^^^^^^^^^^^^^
>>  >>  Trafic is comming from 72.65.73.23 - so the rule don't apply
>>  >>
>>  >>
>>  >>> [root@nub /etc]#
>>  >>  >
>>  >>  > And, as stated above, I am showing connection diverts to natd.  When I
>>  >>  > run the following three tcpdumps:
>>  >>  >
>>  >>  > tcpdump -s 0 -w me_to_nat.pcap -vvv -i rl0 src host 72.65.73.23 and
>>  >>  > dst host 207.210.114.45 and dst port 6667
>>  >>  > tcpdump -s 0 -w nat_to_jail.pcap -vvv -i rl0 src host 72.20.28.202 and
>>  >>  > dst host 207.210.114.45 and dst port 6667
>>  >>  > tcpdump -s 0 -w jail_to_nat.pcap -vvv -i rl0 src host 207.210.114.45
>>  >>  > and dst host 72.20.28.202 and src port 6667
>>  >>  >
>>  >>  > Only the "me_to_nat.pcap" gets any data.  The rest are 0 bytes.  Example:
>>  >>  >
>>  >>  > -rw-r--r--     1 root  wheel      0 Mar 21 14:57 jail_to_nat.pcap
>>  >>  > -rw-r--r--     1 root  wheel  16384 Mar 21 15:24 me_to_nat.pcap
>>  >>  > -rw-r--r--     1 root  wheel      0 Mar 21 14:57 nat_to_jail.pcap
>>  >>  >
>>  >>  > So, can anyone diagnose and fix this?  Thanks.
>>  >>  >
>>  >>  > (P.S.: I'm aware of the DNS methods of doing round-robin, but please
>>  >>  > keep that from this discussion.  I need to port-forward round-robin,
>>  >>  > not whole DNS)
>>  >>  >
>>  >>
>>  >>
>>  >>  _______________________________________________
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>>  >>  http://lists.freebsd.org/mailman/listinfo/freebsd-net
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>>  >>
>>  >
>>  >
>>  >
>>
>>
> 
> 
> 




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