Some office internal LAN cannot access internet after finishing configuring the adding USG firewall, if we change the quondam TPLINK SOHU Router , they can access internet. We have undid all the access control of the USG firewall, the problem also exist.
(1) analyse the difference between the two facilities before and after changing, the TPLINK SOHO Router default the NAT function undoes, but USG doesn’t configure NAT , after the NAT transition, the internal LAN address has been transformed export address to go out, because UGS doesn’t configure NAT , the LAN address cannot be transformed, it means there is no return route of LAN address in the peer end.
(2) USG sets to NAT ,internal LAN can access internet, so the problem is in the peer end.
(3) Relate peer end , the problem has been solved.
(1) The problem of equipment configuration
(2) Other network problem
(1) we should consider the problem on the point of view of the whole network when there have many problems,cannot localise the single facility
(2) use the mode of replacing to check problem, we need catch the key difference point before and after replacing.