# Firefox disable Detection OS



## Handy92 (Feb 24, 2017)

I have FIREFOX on FreeBSD with IPFW, and Opera on Windows10 using NAT Connection. In bought system ipleak http://ipleak.com/full-report/ Detecting OS. My question is how detect it, and how to disable it (Proxy on native??). -> http://i.imgur.com/7h2vbI1.png


```
=====line 1 col 0 lines from top 1 ============================================
ipfw -q -f flush

ipfw -q add 0010 deny all from any to any via lo0
ipfw -q add 0020 deny all from any to 127.0.0.0/8
ipfw -q add 0030 deny all from 127.0.0.0/8 to any
ipfw -q add 0040 deny all from any to any frag

ipfw -q add 0060 allow tcp from me to any 53 out setup keep-state
ipfw -q add 0070 allow udp from me to any 53 out keep-state
ipfw -q add 0080 allow tcp from me to any 80 out setup keep-state
ipfw -q add 0090 allow tcp from me to any 443 out setup keep-state

ipfw -q add 1000 deny log all from any to any
```

My current prefs.js /home/username/.mozilla/firefox/fhaby3bt.default/prefs.js config for firefox with (uBlock, Canvablocker(instalation is need)), disable WebRTC,  Cache to RAM, Blank Start Page, and else.


```
http://pastebin.com/cRAKWBNH
```

SiteCatalog:
http://ipleak.com/full-report/
http://dnsleak.com/results?token=xllab01jvrvgth6e
https://ipleak.net/


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## ridel (Feb 24, 2017)

TCP/IP stack fingerprinting. It is independent of the programs. You can use bridge connection in virtualbox, but ipfw be bypassed by windows traffic in this case.
Also, these settings allow disguise as a windows 7-8-10, but breaks the system:
kern.ipc.maxsockbuf=131072
net.inet.tcp.recvspace=8192
net.inet.ip.ttl=128
net.inet.ip.rfc6864=0

likely this site uses p0f (http://lcamtuf.coredump.cx/p0f3/)
/usr/ports/net-mgmt/p0f


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