IPSec VPN RTBE88U

UXinG — Sat, 29 Aug 2026 11:31:07 GMT

IPsec VPN not working on ASUS RT-BE88U

I would appreciate your help with the following issue.

I have been using an ASUS RT-BE88U router for approximately one year, but I have been unable to establish an IPsec VPN connection. I never experienced this problem with my previous ASUS routers, but I cannot get it working on the RT-BE88U.

So far, I have tried the following:

Connecting from within my local network and externally using my phone’s 5G connection.
Temporarily disabling the router’s firewall.
Manually opening the required VPN ports.
Running the VPN server on my NAS and forwarding the relevant ports to the NAS.

None of these options has worked. It appears that the RT-BE88U is not actually opening the IPsec/VPN ports, or that the VPN traffic is being blocked somewhere. Even when I forward the ports to another device or router, I still cannot establish a connection from outside my network.

Has anyone experienced this issue with the RT-BE88U? Are there any specific settings, known firmware issues, or other tips I could try? I feel that I have already gone through almost all of the usual troubleshooting steps.

Thank you in advance for your help.

Re: IPSec VPN RTBE88U

jzchen — Sun, 30 Aug 2026 09:47:06 GMT

Set it up as you've done with prior ASUS routers, submit a Feedback log. Describe the problem and time/date of failed connection attempt. In about 1 - 2 weeks try the connection again, even without a firmware being published/released.

Re: IPSec VPN RTBE88U

UXinG — Sat, 12 Sep 2026 07:30:29 GMT

Sep 12 08:10:15 01[NET] received packet: from 147.185.132.46[52407] to 212.92.82.249[4500] (296 bytes)
Sep 12 08:10:15 01[ENC] parsed IKE_SA_INIT request 0 [ SA KE No ]
Sep 12 08:10:15 01[IKE] 147.185.132.46 is initiating an IKE_SA
Sep 12 08:10:15 01[CFG] selected proposal: IKE:AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
Sep 12 08:10:15 01[IKE] sending cert request for "C=TW, O=ASUS, CN=ASUS RT-BE88U-1620 Root CA"
Sep 12 08:10:15 01[ENC] generating IKE_SA_INIT response 0 [ SA KE No CERTREQ N(CHDLESS_SUP) N(MULT_AUTH) V ]
Sep 12 08:10:15 01[NET] sending packet: from 212.92.82.249[4500] to 147.185.132.46[52407] (309 bytes)
Sep 12 08:10:45 05[JOB] deleting half open IKE_SA with 147.185.132.46 after timeout
Sep 12 08:11:21 06[NET] received packet: from 147.185.132.46[57950] to 212.92.82.249[4500] (596 bytes)
Sep 12 08:11:21 06[ENC] parsed IKE_SA_INIT request 0 [ SA KE No ]
Sep 12 08:11:21 06[IKE] 147.185.132.46 is initiating an IKE_SA
Sep 12 08:11:21 06[CFG] selected proposal: IKE:AES_CBC_256/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_2048
Sep 12 08:11:21 06[IKE] sending cert request for "C=TW, O=ASUS, CN=ASUS RT-BE88U-1620 Root CA"
Sep 12 08:11:21 06[ENC] generating IKE_SA_INIT response 0 [ SA KE No CERTREQ N(CHDLESS_SUP) N(MULT_AUTH) V ]
Sep 12 08:11:21 06[NET] sending packet: from 212.92.82.249[4500] to 147.185.132.46[57950] (437 bytes)
Sep 12 08:11:51 07[JOB] deleting half open IKE_SA with 147.185.132.46 after timeout
Sep 12 08:16:17 05[NET] received packet: from 192.168.1.6[500] to 212.92.82.249[500] (848 bytes)
Sep 12 08:16:17 05[ENC] parsed ID_PROT request 0 [ SA V V V V V V V V V V V V V V ]
Sep 12 08:16:17 05[IKE] received NAT-T (RFC 3947) vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-08 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-07 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-06 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-05 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-04 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-03 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-02 vendor ID
Sep 12 08:16:17 05[IKE] received draft-ietf-ipsec-nat-t-ike-02\n vendor ID
Sep 12 08:16:17 05[IKE] received XAuth vendor ID
Sep 12 08:16:17 05[IKE] received Cisco Unity vendor ID
Sep 12 08:16:17 05[IKE] received FRAGMENTATION vendor ID
Sep 12 08:16:17 05[IKE] received DPD vendor ID
Sep 12 08:16:17 05[IKE] 192.168.1.6 is initiating a Main Mode IKE_SA
Sep 12 08:16:17 05[CFG] selected proposal: IKE:AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
Sep 12 08:16:17 05[ENC] generating ID_PROT response 0 [ SA V V V V V ]
Sep 12 08:16:17 05[NET] sending packet: from 212.92.82.249[500] to 192.168.1.6[500] (180 bytes)
Sep 12 08:16:17 01[NET] received packet: from 192.168.1.6[500] to 212.92.82.249[500] (228 bytes)
Sep 12 08:16:17 01[ENC] parsed ID_PROT request 0 [ KE No NAT-D NAT-D ]
Sep 12 08:16:17 01[ENC] generating ID_PROT response 0 [ KE No NAT-D NAT-D ]
Sep 12 08:16:17 01[NET] sending packet: from 212.92.82.249[500] to 192.168.1.6[500] (244 bytes)
Sep 12 08:16:17 06[NET] received packet: from 192.168.1.6[500] to 212.92.82.249[500] (108 bytes)
Sep 12 08:16:17 06[ENC] invalid ID_V1 payload length, decryption failed?
Sep 12 08:16:17 06[ENC] could not decrypt payloads
Sep 12 08:16:17 06[IKE] message parsing failed
Sep 12 08:16:17 06[ENC] generating INFORMATIONAL_V1 request 1859980451 [ HASH N(PLD_MAL) ]
Sep 12 08:16:17 06[NET] sending packet: from 212.92.82.249[500] to 192.168.1.6[500] (76 bytes)
Sep 12 08:16:17 06[IKE] ID_PROT request with message ID 0 processing failed
Sep 12 08:16:28 07[NET] received packet: from 178.230.110.60[28037] to 212.92.82.249[500] (848 bytes)
Sep 12 08:16:28 07[ENC] parsed ID_PROT request 0 [ SA V V V V V V V V V V V V V V ]
Sep 12 08:16:28 07[IKE] received NAT-T (RFC 3947) vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-08 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-07 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-06 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-05 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-04 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-03 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-02 vendor ID
Sep 12 08:16:28 07[IKE] received draft-ietf-ipsec-nat-t-ike-02\n vendor ID
Sep 12 08:16:28 07[IKE] received XAuth vendor ID
Sep 12 08:16:28 07[IKE] received Cisco Unity vendor ID
Sep 12 08:16:28 07[IKE] received FRAGMENTATION vendor ID
Sep 12 08:16:28 07[IKE] received DPD vendor ID
Sep 12 08:16:28 07[IKE] 178.230.110.60 is initiating a Main Mode IKE_SA
Sep 12 08:16:28 07[CFG] selected proposal: IKE:AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
Sep 12 08:16:28 07[ENC] generating ID_PROT response 0 [ SA V V V V V ]
Sep 12 08:16:28 07[NET] sending packet: from 212.92.82.249[500] to 178.230.110.60[28037] (180 bytes)
Sep 12 08:16:28 05[NET] received packet: from 178.230.110.60[28037] to 212.92.82.249[500] (228 bytes)
Sep 12 08:16:28 05[ENC] parsed ID_PROT request 0 [ KE No NAT-D NAT-D ]
Sep 12 08:16:28 05[IKE] remote host is behind NAT
Sep 12 08:16:28 05[ENC] generating ID_PROT response 0 [ KE No NAT-D NAT-D ]
Sep 12 08:16:28 05[NET] sending packet: from 212.92.82.249[500] to 178.230.110.60[28037] (244 bytes)
Sep 12 08:16:28 01[NET] received packet: from 178.230.110.60[28102] to 212.92.82.249[4500] (108 bytes)
Sep 12 08:16:28 01[ENC] invalid ID_V1 payload length, decryption failed?
Sep 12 08:16:28 01[ENC] could not decrypt payloads
Sep 12 08:16:28 01[IKE] message parsing failed
Sep 12 08:16:28 01[ENC] generating INFORMATIONAL_V1 request 3753807788 [ HASH N(PLD_MAL) ]
Sep 12 08:16:28 01[NET] sending packet: from 212.92.82.249[500] to 178.230.110.60[28037] (76 bytes)
Sep 12 08:16:28 01[IKE] ID_PROT request with message ID 0 processing failed
Sep 12 08:16:47 05[JOB] deleting half open IKE_SA with 192.168.1.6 after timeout
Sep 12 08:16:58 07[JOB] deleting half open IKE_SA with 178.230.110.60 after timeout

Re: IPSec VPN RTBE88U

UXinG — Sat, 12 Sep 2026 07:34:36 GMT

ik looks like the asus doesn't accept the UDP packets

topic IPSec VPN RTBE88U in Networking

IPSec VPN RTBE88U

Re: IPSec VPN RTBE88U

Re: IPSec VPN RTBE88U

Re: IPSec VPN RTBE88U