The USG2130 and the USG3040 are connected to each other over an IPSec VPN. Intranet users of the USG2130 can access the intranet consulting service of the USG3040, but they have to withstand a latency of more than 400 ms when they access an address on the 22.214.171.124 intranet segment of the USG3040. Intranet users on the 126.96.36.199 intranet segment of the USG3040 do not suffer a latency when they access the intranet segments 172.17.0.0 and 192.168.0.0 of the USG2130.
Change the public IP addresses used by the intranet users of the USG3040 to private IP addresses. The problem of a long latency disappears. Alternatively, you can configure a detailed route pointing to the destination IP address on the 188.8.131.52 network segment on the USG2130.
At first, it is suspected that the physical link to the server is problematic, but server can normally access the intranet of the USG2130, so the problem is not caused by a server link fault. Therefore, the problem occurs because intranet users of the USG3040 uses public IP addresses on the 184.108.40.206 as private IP addresses.
When a public IP address is used as a private one on the intranet, the peer end searches for the IP address on the public network when the IP address is pinged from the peer end. This exerts a great impact on intranet IP addresses. Therefore, it is recommended not to use public IP addresses as private IP addresses during communication with the public network.