What firewall rules to set for an internal network?


the internet connection is made by  LinkSys modem router Zyxel Prestige 600 series

 LinkSys modem router Zyxel Prestige 600 series

the linksys is connected with dlink router DSR-500N

the computer inside the network go to the internet, use outlook (smpt pop default port)

there no database connection to internet

I post a screenshot for the DLINK router

and a screenshot for the prestige linksys (it seems there are not firewall rules in the linksys)

Dlink Firewall rules setupMr THOMAS Patrice
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NetExpert Network Solutions Pte LtdTechnical SpecialistCommented:
Based on your update, I can see the the computer in LAN network can connect internet?

Exactly what is the issue in your network?

//there no database connection to internet//   -- what does it mean?  does the database server not able to connect internet
patrocle_runAuthor Commented:

yes, the all computer in network connect to internet without problem

the server also.

the database not need to connect to internet

NetExpert Network Solutions Pte LtdTechnical SpecialistCommented:
@patrice  -- currently whats the issue in your network?

can you elaborate a bit please?
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patrocle_runAuthor Commented:
there are no problem in the network

i thought is was not normal that there are not firewall rules
patrocle_runAuthor Commented:
The good firewall rules is :

- block all ports

- list all application we need (HTTP,FTP,POP,SMTP,etc...)

- open only ports needed (80,8080,443,20,21,110,...etc)

Generally, it needs :

internet ( port 80,8080 HTTP) , HTTPS : port 443
ftp ( port 20,21)
mail (SMTP,POP  : port 110,25)

It needs to be ensured that all ports (used by applications that connect to internet) are opened

note : SMTP secured and POP secured use other ports

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patrocle_runAuthor Commented:
this is answer for the question.
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