[strongSwan] Tunnels with dynamic IP and another route issue

Dusan Ilic dusan at comhem.se
Sun Apr 30 12:28:48 CEST 2017


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 dev br0  proto static  src 10.1.1.1 # LAN passthrough?
default via 85.24.x.x dev vlan847  proto static  src 10.1.1.1

So instead of a route to 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 
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 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 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
>>
>>
>
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