Date: Sun, 25 Nov 2007 15:00:50 +0100 From: Roger Olofsson <raggen@passagen.se> To: Jerahmy Pocott <quakenet1@optusnet.com.au> Cc: FreeBSD Questions <freebsd-questions@freebsd.org> Subject: Re: Difficulties establishing VPN tunnel with IPNAT Message-ID: <47498012.9000201@passagen.se> In-Reply-To: <57A2907C-0660-458C-B254-3C893B4532CB@optusnet.com.au> References: <7BB1A732-4F07-499E-A183-22776FEEEE90@optusnet.com.au> <47482C2C.6010700@passagen.se> <894E3C92-2C45-4FC2-8C56-D4B303F0349F@optusnet.com.au> <4748A115.1010002@passagen.se> <57A2907C-0660-458C-B254-3C893B4532CB@optusnet.com.au>
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Jerahmy Pocott skrev: > The Sonic Wall client doesn't trigger ANY firewall rules, which is why I > thought > there must be something going wrong with the NAT. It actually > establishes the > tunnel okay but never gets an IP address, from my understanding this client > uses some sort of dhcp over ipsec to provision the client address.. > > What I am getting using the standard PPTP method are a bunch of hits: > > fxp1 @0:25 b x.x.x.x -> 10.0.0.3 PR gre len 20 (93) IN NAT > > (rule @0:25 is the final 'block all' rule) > > What is protocol 'gre'? Why is a NAT'd packet getting blocked?! > > Thanks! > J. > > On 25/11/2007, at 9:09 AM, Roger Olofsson wrote: > >> Hello again Jerahmy, >> >> I would suggest that you verify what port(s) and protocol(s) 'Sonic >> Wall Global VPN Client' needs to work. >> >> I would also suggest that you look in the logfile from ipf to see what >> it's blocking and when. >> >> My guess is that the VPN client is using a protocol like IPSEC (IP >> protocol 50) and possibly port 500 (IKE) for which you will have to >> activate the ipnat proxy. >> >> map WAN internal_ip/24 -> 0.0.0.0/32 proxy port 500 ipsec/udp >> >> You might also try to disable the blocking of fragged packets. For >> some VPN clients this can cause problems. >> >> Good luck! >> >> /Roger >> >> >> >> Jerahmy Pocott skrev: >>> Sorry let me clarify.. >>> There are two issues, one is connecting to any external VPN, with no >>> filter I >>> can establish a connection to PPTP VPN, but the 'Sonic Wall Global >>> VPN Client' >>> still fails to connect even with no filter rules. >>> The redirect for the CVS server has an ipf rule to allow traffic on >>> that port, but >>> users are getting connection refused messages. >>> I will include my ipf rules, I clearly need some sort of rule to >>> allow inbound for >>> the VPN to work, though I think the ipnat is breaking the Sonic Wall >>> client. Which >>> is strange because everything worked fine with ipfw/natd. >>> Here are my ipf rules: >>> # Allow all in/out on internel interface >>> pass in quick on fxp0 all >>> pass out quick on fxp0 all >>> # Allow all in/out on loopback interface >>> pass in quick on lo0 all >>> pass out quick on lo0 all >>> # Allow all out-going on public interface and keep state >>> pass out quick on fxp1 proto tcp from any to any flags S keep state >>> pass out quick on fxp1 proto udp from any to any keep state >>> pass out quick on fxp1 proto icmp from any to any keep state >>> # Block all inbound traffic from non-routable or reserved address spaces >>> block in quick on fxp1 from 192.168.0.0/16 to any #RFC 1918 >>> private IP >>> block in quick on fxp1 from 172.16.0.0/12 to any #RFC 1918 >>> private IP >>> block in quick on fxp1 from 10.0.0.0/8 to any #RFC 1918 >>> private IP >>> block in quick on fxp1 from 127.0.0.0/8 to any #loopback >>> block in quick on fxp1 from 0.0.0.0/8 to any #loopback >>> block in quick on fxp1 from 169.254.0.0/16 to any #DHCP auto-config >>> block in quick on fxp1 from 192.0.2.0/24 to any #reserved for docs >>> block in quick on fxp1 from 204.152.64.0/23 to any #Sun cluster >>> interconnect >>> block in quick on fxp1 from 224.0.0.0/3 to any #Class D & E >>> multicast >>> # Block frags >>> block in quick on fxp1 all with frags >>> # Block short tcp packets >>> block in quick on fxp1 proto tcp all with short >>> # block source routed packets >>> block in quick on fxp1 all with opt lsrr >>> block in quick on fxp1 all with opt ssrr >>> # Block anything with special options >>> block in quick on fxp1 all with ipopts >>> # Block public pings >>> block in quick on fxp1 proto icmp all icmp-type 8 >>> # Block ident >>> block in quick on fxp1 proto tcp from any to any port = 113 >>> # Block all Netbios service. 137=name, 138=datagram, 139=session >>> # Block MS/Windows hosts2 name server requests 81 >>> block in quick on fxp1 proto tcp/udp from any to any port = 137 >>> block in quick on fxp1 proto tcp/udp from any to any port = 138 >>> block in quick on fxp1 proto tcp/udp from any to any port = 139 >>> block in quick on fxp1 proto tcp/udp from any to any port = 81 >>> # Allow CVS access >>> pass in quick on fxp1 proto tcp/udp from any to any port = 2401 >>> # Logged Blocking Rules # >>> # Block nmap OS fingerprint attempts >>> block in log first quick on fxp1 proto tcp from any to any flags FUP >>> # Block all other in coming traffic >>> block in log first quick on fxp1 all >>> Thanks for the help! >>> J. >>> On 25/11/2007, at 12:50 AM, Roger Olofsson wrote: >>>> Hello Jerahmy, >>>> >>>> Assuming you want to connect from the outside to your VPN. >>>> >>>> Have you made sure that port 2401 is open for inbound traffic in >>>> your ipf.rules? >>>> >>>> You might also want to do 'ipnat -C -f <path to ipnat.rules>'. Man >>>> ipnat ;^) >>>> >>>> Greeting from Sweden >>>> /Roger >>>> >>>> >>>> >>>> Jerahmy Pocott skrev: >>>>> Hello, >>>>> I recently decided to give ipf and ipnat a try, previously I had >>>>> always been using >>>>> ipfw and natd. Since switching over I can no longer establish a VPN >>>>> tunnel from >>>>> any system behind the gateway. >>>>> I did 'ipf -F a' to flush all rules but I was still unable to >>>>> connect so I think it's a problem >>>>> with ipnat? Also my redirect from ipnat doesn't seem to work either. >>>>> These are the only ipnat rules I have: >>>>> (fxp1 is the external interface) >>>>> # ipnat built in ftp proxy rules >>>>> map fxp1 10.0.0.0/24 -> 0/32 proxy port 21 ftp/tcp >>>>> map fxp1 0.0.0.0/0 -> 0/32 proxy port 21 ftp/tcp >>>>> # CVS Server on Fileserv >>>>> rdr fxp1 0/32 port 2401 -> 10.0.0.2 port 2401 tcp/udp >>>>> # nat all out going traffic on fxp1 from internal lan >>>>> map fxp1 10.0.0.0/24 -> 0/32 >>>>> I can post my firewall rules too if that would help, however with >>>>> NO rules set it >>>>> still didn't work so I don't think that would help.. (I'm using the >>>>> klm which is default >>>>> to accept?) >>>>> Thanks! >>>>> J. >>>>> _______________________________________________ >>>>> freebsd-questions@freebsd.org mailing list >>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>>>> To unsubscribe, send any mail to >>>>> "freebsd-questions-unsubscribe@freebsd.org" >>>> _______________________________________________ >>>> freebsd-questions@freebsd.org mailing list >>>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>>> To unsubscribe, send any mail to >>>> "freebsd-questions-unsubscribe@freebsd.org" >>> _______________________________________________ >>> freebsd-questions@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>> To unsubscribe, send any mail to >>> "freebsd-questions-unsubscribe@freebsd.org" >> _______________________________________________ >> freebsd-questions@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >> To unsubscribe, send any mail to >> "freebsd-questions-unsubscribe@freebsd.org" > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" > > Hello Jerahmy, (sorry for top-posting, btw). Gre is protocol 47. In your firewall rules you only allow/block protocols tcp/udp/icmp. If you want to use PPTP you will need to allow both the port and the protocol for it. Did you find out what ports and what protocols the VPN client needs? In my earlier post I guessed that you would have to enable the IPSEC proxy and allow protocol 50 and port 500. I gave an example on how to enable the IPSEC proxy in ipnat.conf, ie: map WAN 10.0.0.0/24 -> 0.0.0.0/32 proxy port 500 ipsec/udp You could also try to do like this (early in the ipf.conf file), depending on if you trust the vpn server or not: pass out quick on WAN proto tcp/udp from <ip of vpn client> to <ip of vpn server> pass in quick on WAN from <ip of vpn server> to <ip of vpn client> In your original question you mentioned having problems with CVS. From the looks of it, you redirect CVS to 10.0.0.2, meaning that all users on that machine can use CVS. If you mean that users are on other machines, ie, not on 10.0.0.2 they won't be able to use CVS. The solution to this would be to remove your rdr to 10.0.0.2. My own rules for stateful filtering looks like this, I am only allowing ports above 1023 for stateful: # [ Enable stateful connections LAN->WAN for all ports > 1023 tcp/udp ] pass out quick on WAN proto tcp from any to any port > 1023 flags S keep state keep frags pass out quick on WAN proto udp from any to any port > 1023 keep state keep frags BTW, to make changes to ipf/ipnat I use the following commands: ipf -Fa -f <path_to_changed_ipf_file> ipnat -C -f <path_to_changed_ipnat_file> Good luck! /Roger
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