[strongSwan] how to increase timeout for "deleting half open IKE_SA with <someIP> after timeout" ?

[Andreas Steffen]

Hello Harald,

the half_open_timeout can be set in strongswan.conf:

charon {
  half_open_timeout = 120
}

to set the timeout to 120 seconds.

Best regards

Andreas

On 14.05.21 11:06, Harald Dunkel wrote:
> Hi folks,
> 
> I have a few road warriors (3 out of ~140) having severe problems to
> connect via IKEv2. Within the last 4 weeks they had >1000 problems
> during IKE SA init each, e.g.:
> 
> May 12 09:55:28 18[NET1] <92244> received packet: from
> 192.168.1.177[61416] to 10.0.0.17[500] (432 bytes)
> May 12 09:55:28 18[ENC1] <92244> parsed IKE_SA_INIT request 0 [ SA KE No
> N(REDIR_SUP) N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) ]
> May 12 09:55:28 18[IKE0] <92244> 192.168.1.177 is initiating an IKE_SA
> May 12 09:55:28 18[IKE2] <92244> IKE_SA (unnamed)[92244] state change:
> CREATED => CONNECTING
> May 12 09:55:28 18[CFG1] <92244> selected proposal:
> IKE:AES_CBC_256/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_2048
> May 12 09:55:28 18[IKE1] <92244> remote host is behind NAT
> May 12 09:55:28 18[IKE2] <92244> sending strongSwan vendor ID
> May 12 09:55:28 18[IKE1] <92244> sending cert request for "C=DE,
> O=example AG, CN=ws-CA"
> May 12 09:55:28 18[IKE1] <92244> sending cert request for "C=DE,
> O=example AG, OU=example Certificate Authority, CN=root-CA"
> May 12 09:55:28 18[IKE1] <92244> sending cert request for "C=DE, ST=NRW,
> O=example AG, OU=TI, CN=ipsec-ca"
> May 12 09:55:28 18[ENC1] <92244> generating IKE_SA_INIT response 0 [ SA
> KE No N(NATD_S_IP) N(NATD_D_IP) CERTREQ N(FRAG_SUP) N(CHDLESS_SUP)
> N(MULT_AUTH) V ]
> May 12 09:55:28 18[NET1] <92244> sending packet: from 10.0.0.17[500] to
> 192.168.1.177[61416] (541 bytes)
> May 12 09:55:58 31[JOB1] <92244> deleting half open IKE_SA with
> 192.168.1.177 after timeout
> May 12 09:55:58 31[IKE2] <92244> IKE_SA (unnamed)[92244] state change:
> CONNECTING => DESTROYING
> 
> Obviously there is a 30sec timeout on the IPsec gateway. Is there
> a chance to increase this timeout (using stroke, ie. ipsec.conf)?
> https://wiki.strongswan.org/projects/strongswan/wiki/ConnSection
> mentions only the DPD timeout (150 sec per default) and the inac-
> tivity timeout (child sa only, as it seems).
> 
> Would it be wise to resend the IKE_SA_INIT response (lets say) 3
> times?
> 
> 
> Every helpful comment is highly appreciated
> 
> Harri


======================================================================
Andreas Steffen                         andreas.steffen at strongswan.org
strongSwan - the Open Source VPN Solution!          www.strongswan.org
strongSec GmbH, 8952 Schlieren (Switzerland)
======================================================================