Hi Noel,
So, are you saying that there is no way to make Strongswan aware of a
domain name have changed IP-address without restarting it manually?
Den 2017-07-22 kl. 01:49, skrev Noel Kuntze:
Hi Dusan,
I took a "quick" look at the code[1] and it seems the DNS names are only
resolved once the result replaces the original destination.
So it has nothing to do with caching. Just with a disadvantageous design
decision.
Kind regards
Noel
[1]
https://github.com/strongswan/strongswan/blob/master/src/libcharon/sa/ike_sa.c#L1470
On 21.07.2017 00:19, Dusan Ilic wrote:
Okey, so I just did a forced release/renew on the same endpoint, dynamic DNS
updated shortly the new IP (ttl 5 min) and after like 10 min or so another
endpoint reconnected again (a fortigate, I have two endpoints), however the
troubling endpoint (also strongswan) havent connected yet.
When logging in to the remote endpoint and pinging the domain name, it resolves
to the new IP, but below are the output from both sides of the tunnel when
trying to manually run ipsec up-command.
On the remote endpoint:
First of, running ipsec statusall connection shows as if the tunnel is still
up, maybe thats the problem that Strongswan thinks its up even if it isn't?
ESTABLISHED 46 minutes ago,
94.254.123.x[local.host.name]...85.24.241.x[85.24.241.x]
IKE SPIs: 1dffaab2cafa2f48_i 15e867fa149370f0_r*, pre-shared key
reauthentication in 22 hours
IKE proposal: AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_2048
INSTALLED, TUNNEL, ESP SPIs: cf0473a2_i c45028cb_o
AES_CBC_128/HMAC_SHA1_96, 8275 bytes_i (2616s ago), 81235 bytes_o (8s ago),
rekeying in 7 hours
192.168.1.0/24 === 10.1.1.0/26
Command ipsec up connection
initiating IKE_SA to 85.24.241.x
generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) ]
sending packet: from 94.254.123.x[500] to 85.24.241.x[500]
retransmit 1 of request with message ID 0
sending packet: from 94.254.123.x[500] to 85.24.241.x[500]
On the local endpoint (with new IP):
initiating IKE_SA to 94.254.123.x
generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP)
N(FRAG_SUP) N(HASH_ALG) N(REDIR_SUP) ]
sending packet: from 85.24.244.x[500] to 94.254.123.x[500] (464 bytes)
received packet: from 94.254.123.x[500] to 85.24.244.x[500] (36 bytes)
parsed IKE_SA_INIT response 0 [ N(NO_PROP) ]
received NO_PROPOSAL_CHOSEN notify error
establishing connection 'wesafe' failed
And when restarting Strongswan on the remote endpoint, it connects again...
Den 2017-07-20 kl. 12:00, skrev Dusan Ilic:
Hi,
I have some issues with a site to site tunnel with two dynamic endpoints. One
side almost never changes IP-adress (it is DHCP however), the other side
changes more frequently. Both endpoints IP-adresses are using dynamic DNS and
have a corresponding domain name associated at all times.
Today one side changed IP, and the new IP have been updated in public DNS. I
understand DNS propagation and caching, but I seem to not understand how
Strongswan handles and acts upon it.
For example, I have set keyingtries to %forever on both sides, so that they
continuesly tries to reconnect when connections is lost. I have also changed
the global initiation parameter from default 0 to 60 s, so that it retries
unsuccesful connections attempts.
Now the other side is trying to reconnect to the old IP still, however if I
ping the hostname from that endpoint it resolves to the new, correct IP. It
seems like Strongswan is caching the old DNS some how?
At last I tried to restart Strongswan and then it picked up the new IP.
I would like to have a system that solves this by itself, so I don't need to
manually have to intervene each and everythime any of the endpoints get a new
IP. How can this best be achieved?
