[strongSwan] Tunnels with dynamic IP and another route issue

Tue May 2 09:41:00 CEST 2017

Yes, that's the reason why that happens. No, you need to start using another subnet.

On 02.05.2017 02:02, Dusan Ilic wrote:
> I seem to have found the problem, it was on my local endpoint. The gateway have default IP-table rules in prerouting table dropping traffic entering any WAN-interface destined to a LAN-subnet, which I understand is normal as long as their isn't any IPsec involved :) Below exlude rule solves it.
>
> iptables -t mangle -I PREROUTING -d 10.1.1.0/26 -i $(nvram get wan3_ifname) -m policy --dir in --pol ipsec --proto esp -j ACCEPT
>
>
> Now routing everything over IP-sec tunnel works great, but instead a new issue have risen. My VPN remote access users cannot reach the internet anymore (or the local subnet for that matter) when the gateway are routing all traffic over another IPsec-tunnel, and from the LAN I cannot ping the VPN-client (Android Strongswan) either. I'm wildly guessing this is because my VPN-clients are getting IP's from the local subnet (rightsourceip=%dhcp), the same subnet that I have to create a passthrough connection for. Is this solvable in an easy way, or am I forced put my VPN-clients on a separate subnet?
>
> Den 2017-05-01 kl. 14:57, skrev Noel Kuntze:
>> I can't  help you further easily. You need to check what happens to the packets and what actually needs to happen.
>>
>> On 30.04.2017 23:25, Dusan Ilic wrote:
>>> I have added following on local router
>>>
>>> iptables -t nat -I POSTROUTING -s 10.1.1.0/26 -o vlan847 -m policy --dir out --pol ipsec --proto esp -j ACCEPT
>>> (before it was iptables -t nat -I POSTROUTING -s 10.1.1.0/26 -d 192.168.1.0/24 -o vlan847 -m policy --dir out --pol ipsec --proto esp -j ACCEPT)
>>>
>>> And on remote router
>>>
>>> iptables -I FORWARD -s 10.1.1.0/26 -j ACCEPT
>>> iptables -t nat -I POSTROUTING -s 10.1.1.0/26 -j MASQUERADE
>>>
>>> And now when the tunnel is up, internet doesnt work at all (all pings time out), however I can still reach the remote subnet 192.168.1.0. What is the best way to troubleshoot, if the error is on the local gateway or on the remote?
>>>
>>>
>>> Den 2017-04-30 kl. 20:39, skrev noel.kuntze+strongswan-users-ml at thermi.consulting:
>>>> Fix your NAT rules.
>>>>
>>>> Am 30. April 2017 12:28:48 MESZ schrieb Dusan Ilic <dusan at comhem.se>:
>>>>
>>>>      Okey, so I found info about adding a "passthrough" connection for my
>>>>      local LAN. I have done this now and when i start the connection the
>>>>      network connection isn't cut off, however, it seems like my internet
>>>>      traffic i still using my local gateway (browsed to a check my ip-page).
>>>>      I can however still ping the remote network.
>>>>
>>>>      Here is my tabel 220
>>>>
>>>>      # ip route show table 220
>>>>      10.1.1.0/26 <http://10.1.1.0/26> dev br0  proto static  src 10.1.1.1 <http://10.1.1.1> # LAN passthrough?
>>>>      default via 85.24.x.x dev vlan847  proto static  src 10.1.1.1 <http://10.1.1.1>
>>>>
>>>>      So instead of a route to 192.168.1.0/24 <http://192.168.1.0/24> a default route is added, but it
>>>>      looks like it doesn't go through the tunnel... traffic to 192.168.1.0/24 <http://192.168.1.0/24>
>>>>      do get tunneled still though.
>>>>
>>>>      Den 2017-04-30 kl. 11:59, skrev Dusan Ilic:
>>>>
>>>>          Hello again, It worked with the hack! Thank you! Last question (hopefully! :P)), if I would like to use the remote endpoint to route *all* traffic over the vpn, is below the correct way? I have changed rightsubnet locally to 0.0.0.0/0 and leftsubnet remotely to 0.0.0.0/0, I have also added NAT on the remote router for the local subnet on the local endpoint, and finally I have added the local subnet to table 220 on the local router. I have also replaced the Iptable forward rule on local endpoint with 0.0.0.0/0 instead of only the remote subnet. However, when I up the connection on the local router in a couple of seconds my SSH connection stops responding, and I cannot reach the local gateway or internet any longer. I have to reboot the local router to get access again. Is this familiar to you? What could be happening here? Den 2017-04-29 kl. 18:44, skrev Noel Kuntze:
>>>>
>>>>              Hello Dusan, On 29.04.2017 18:34, Dusan Ilic wrote:
>>>>
>>>>                  It works! I found a hidden setting under Phase 1 in Fortigate where i could add the local ID. Added it's dynamic dns hostname and now it connects.
>>>>
>>>>              Great!
>>>>
>>>>                  However, I still have issues with another endpoint I'm testing. My local endpoint have Strongswan 5.5.1 and the remote endpoint have 4.5.2. Would that present any issues or incompatibilites? Unfortunately it's not possible to upgrade the remote endpoint (Strongswan).
>>>>
>>>>              Pluto resolves IDs that are FQDNs. I think there was a hack, where you add the at-character in front of the FQDN in the ID settings and that stops it from doing that. Might apply to charon, too in such a low version number. Try the hack.
>>>>
>>>>                  I tried below, per your suggestion left=%local.example leftid=local.example right=%remote.example rightid=remote.example remote.example : PSK "PSKGOESHERE" Log when local sides initiates connection: parsed IKE_AUTH response 1 [ N(AUTH_FAILED) ] received AUTHENTICATION_FAILED notify error
>>>>
>>>>              You need to read the remote logs when the remote side sends you an error message.
>>>>
>>>>                  Log when remote side initiates connection: Apr 29 16:32:20 R6250 daemon.info <http://daemon.info> charon: 10[CFG] looking for peer configs matching 85.24.x.x[85.24.x.x]...94.254.x.x[94.254.x.x] Apr 29 16:32:20 R6250 daemon.info <http://daemon.info> charon: 10[CFG] no matching peer config found It looks like the same issue, the remote endpoint doesnt send the configured ID?
>>>>
>>>>              Yes.
>>>>
>>>>                  And another question, when using dynamic hostnames instead of IP's as "right", how often does Strongswan make a new DNS-lookup? How does Strongswan handle the situation where let's say the remote endpoint suddenly receives a new IP? Or if the local side receives a new IP during established connection?
>>>>
>>>>              strongSwan does a DNS lookup whenever it tries to select a configuration. Well, depends on if mobike is used or no and if the peer who's IP changed can't send any traffic anymore. Mobike and connectivity: IKE_SA and CHILD_SAs are migrated No mobike and connectivity: Don't know. Maybe a new IKE_SA is negotiated, because the one peer knows the local address has vanished (and the CHILD_SAs migrated?). No mobike and no connectivity: Timeout, if DPD is used. Otherwise the IKE_SA and CHILD_SAs remain until the remote peer connects again. Mobike and no connectivity: Timeout, if DPD is used. Otherwise the IKE_SA and CHILD_SAs remain until the remote peer connects again. Kind regards, Noel
>>>>
>>>>         
>>>> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>>>>          Users mailing list Users at lists.strongswan.org https://lists.strongswan.org/mailman/listinfo/users
>>>>
>>>>
>>>> Sent from mobile
>>
>
>

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