title: Server going slow after IPTables configuration? Try this
---
body:

Recently I've started the migration of my company's servers to a new provider.
After checking that the OS installed on the -now- old servers was Ubuntu 8.04
(holy shit), I decided to make a fresh install of CentOS 6.3, cleaning up all
the servers contents and setting up everything from scratch.

After setting my iptables rules (INPUT whitelisted, OUTPUT accept all) I
noticed a big delay on every connection made to my server. After checking a
lot of things, these two solved the issue:

## Enable unilimited traffic on your loopback interface

``` text
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
```

## Enable traffic for connections started by your server

``` text
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
```

Hope this solves your issue as it did with mine.
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pub_date: 2013-02-27
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