Internet issue after changing WAN to DHCP from PPOE

Why did you change from PPoE to DHCP, they are different connection methods?

Ian

The ISP provider changed the ONT.

could you please help me to fix the issue? 

Why are you using a 10:address on your external interface? Your router should be in bridge mode so you get a real address.

ian

The isp provided me 10: range, but our network is in 192.168.1.1.

Will the issue get fixed if I change the isp address to a c class IP? 

No,, changing the address will not fix the issue, is your modem in bridge mode?

you said your internal address is 192.168.x.x, why have you setup the dhcp server with a 10 range.?

ian

I don't have access to the modem. The ISP manages it.

They are using DHCP i think. 

Hi, you did not answer all of my questions.

ian

But the DHCP in sophos is not using. 

It is disabled

Based on what you are saying you do not need a Nat on your XG. The failing bit sounds like your isp has issues with their gateway router. You best follow up wit them.

ian

NAT in V18 would help in case of such problems. If you are running V18, simply enable the default SNAT on the bottom of the NAT window. 

Please let me try to understand your answer. You are advising a double Nat might fix his website access, but if he is using the web proxy it will not go through the Nat, correct?

Please let me try to understand your answer. You are advising a double Nat might fix his website access, but if he is using the web proxy it will not go through the Nat, correct?

Basically a SNAT will not "harm". SNAT is something, this will properly not fix the root cause but can fix many problems in the own network.