# Pi-Hole and iptables

**URL:** <https://discourse.pi-hole.net/t/pi-hole-and-iptables/14452>\
**Category:** Help\
**Created:** [November 14, 2018, 6:11pm UTC](https://discourse.pi-hole.net/t/pi-hole-and-iptables/14452 "2018-11-14T18:11:25Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![jfb](https://discourse-cdn.pi-hole.net/user_avatar/discourse.pi-hole.net/jfb/32/4332_2.png) [@jfb](https://discourse.pi-hole.net/u/jfb)\
**Post date:** [November 15, 2018, 1:34pm UTC](https://discourse.pi-hole.net/t/pi-hole-and-iptables/14452/5 "2018-11-15T13:34:45Z")

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> [@MountFX](#):
>
> FritzBox cannot use raspberry pi anymore as DNS server and uses the fallback DNS sever.

There is no effective concept of a "fallback DNS server", and if you have a second DNS server listed in the router (that is not a Pi-Hole), then some of your network traffic will route to that DNS and bypass Pi-Hole.

> [@Why should Pi-hole be my only DNS server?](https://discourse.pi-hole.net/t/why-should-pi-hole-be-my-only-dns-server/3376):
>
> Reduced Ad Blocking Capability The main reason you should Pi-hole as your only DNS server is that you will see increased performance in the blocking of ads. If you have two DNS servers (Pi-hole and something else), your network clients may not always query Pi-hole for name resolution. If a query happens to be answered from a non-Pi-hole DNS server, your block lists will not apply (since that DNS server doesn't know about them). All Queries Need To Go Through Pi-hole First Since other DNS serv…

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_[View the full topic](https://discourse.pi-hole.net/t/pi-hole-and-iptables/14452)._