why the ipsec vpn is up but the traffic can not be forwarded

Latest reply: Apr 20, 2018 10:09:13 547 1 2 0

the topology like this:


AR1 establish the ipsec vpn with AR2, we found that the ipsec vpn is up, but the traffic is not ok.

AR1 can not ping AR2.

we checked the configuration of both AR, we found that , on the AR1, there is a commands : but

ipsec authentication sha2 compatible enable

but the AR2 did not have this configuration, we checked the function for this commands:



The ipsec authentication sha2 compatible enable command enables SHA-2 to be compat

ible with earlier versions.

When IPSec uses the SHA-2 algorithm, if the devices on two ends of an IPSec tunnel are from different vendors or run different software versions, they may use different encryption and decryption methods. In this situation, traffic between devices is interrupted.

To solve this problem, run the ipsec authentication sha2 compatible enable command to enable SHA-2 to be compatible with earlier versions.


after we add this commands on the AR2, the traffic is ok, we can ping from AR1 to AR2




  • x
  • convention:

Created Apr 20, 2018 10:09:13 Helpful(0) Helpful(0)

  • x
  • convention:


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