sudo ls -l /etc/NetworkManager/dispatcher.d/inetsquid.sh
-rwxr-xr-x 1 vovan users 655 янв  9 20:45 /etc/NetworkManager/dispatcher.d/inetsquid.sh

#!/bin/bash
R=$(nm-tool|grep State|cut -f2|grep -o "connected (global)")
B='connected'
echo $R | grep $B >/dev/null 2>&1; while [ "$?" != "0" ];
do
echo "Интернета пока НЕТ"
done
echo $R | grep $B >/dev/null 2>&1; if [ "$?" = "0" ];
then
ping -c 1 192.168.100.1 > /root/ping
a=$(cat /root/ping | tail -n2 | head -n1 | awk {'print $6'} | sed s/%//)
echo $a
if [ $a != 0 ]
then date > /root/fail && cp /etc/squid/squid.conf.home /etc/squid/squid.conf && systemctl restart squid
else date > /root/fail && cp /etc/squid/squid.conf.work /etc/squid/squid.conf && systemctl restart  squid
fi
fi
echo "ЗАЕБИСЬ НАЧАЛЬНИКА"
exit 0

extra/network-manager-applet 0.9.6.4-1 [установлен]
    GNOME frontends to NetWorkmanager
extra/networkmanager 0.9.6.4-1 [установлен]
    Network Management daemon

P PREROUTING ACCEPT -c 73 26203
-P INPUT ACCEPT -c 228 39315
-P FORWARD ACCEPT -c 0 0
-P OUTPUT ACCEPT -c 176 14032
-P POSTROUTING ACCEPT -c 176 14032
-N DIVERT
-A PREROUTING -p tcp -m socket -c 167 13859 -j DIVERT
-A PREROUTING -p tcp -m tcp --dport 80 -c 0 0 -j TPROXY --on-port 3129 --on-ip 0.0.0.0 --tproxy-mark 0x1/0x1
-A DIVERT -c 167 13859 -j MARK --set-xmark 0x1/0xffffffff
-A DIVERT -c 167 13859 -j ACCEPT

curl -I4 http://version6.ru/
curl: (7) couldn't connect to host

sudo iptables -S -v -t mangle
[sudo] password for vovan: 
-P PREROUTING ACCEPT -c 275 40777
-P INPUT ACCEPT -c 743 304174
-P FORWARD ACCEPT -c 0 0
-P OUTPUT ACCEPT -c 735 194966
-P POSTROUTING ACCEPT -c 735 194966
-N DIVERT
-N prevent_tproxy_loop
-A PREROUTING -p tcp -m socket -c 4072 946519 -j prevent_tproxy_loop
-A PREROUTING -p tcp -m tcp --dport 80 -c 0 0 -j TPROXY --on-port 3129 --on-ip 0.0.0.0 --tproxy-mark 0x1/0xffffffff
-A PREROUTING -p tcp -m socket -c 0 0 -j DIVERT
-A PREROUTING -p tcp -m tcp --dport 80 -c 0 0 -j TPROXY --on-port 3129 --on-ip 0.0.0.0 --tproxy-mark 0x1/0x1
-A DIVERT -c 0 0 -j MARK --set-xmark 0x1/0xffffffff
-A DIVERT -c 0 0 -j ACCEPT
-A prevent_tproxy_loop -c 4072 946519 -j MARK --set-xmark 0x1/0xffffffff
-A prevent_tproxy_loop -c 4072 946519 -j ACCEPT

sudo ss -npl | grep squid
LISTEN     0      128                      :::3129                    :::*      users:(("squid",1970,17))

http_port 3129 tproxy 

iptables -t mangle -N DIVERT
iptables -t mangle -A DIVERT -j MARK --set-mark 1
iptables -t mangle -A DIVERT -j ACCEPT
iptables  -t mangle -A PREROUTING -p tcp -m socket -j DIVERT
iptables  -t mangle -A PREROUTING -p tcp --dport 80 -j TPROXY --tproxy-mark 0x1/0x1 --on-port 3129

 ip -f inet rule add fwmark 1 lookup 100
ip -f inet route add local default dev eth1 table 100

echo 1 > /proc/sys/net/ipv4/ip_forward
echo 0 > /proc/sys/net/ipv4/conf/default/rp_filter
echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter
echo 0 > /proc/sys/net/ipv4/conf/eth1/rp_filter

curl -I4 http://version6.ru/
HTTP/1.1 200 OK
X-Powered-By: PHP/5.3.3-7+squeeze14
Set-Cookie: DokuWiki=kefdjai034aifjfrbvpu2365s0; path=/; HttpOnly
Set-Cookie: DW68700bfd16c2027de7de74a5a8202a6f=deleted; expires=Mon, 07-Nov-2011 20:22:34 GMT; path=/; httponly
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Type: text/html; charset=utf-8
Date: Tue, 06 Nov 2012 20:22:35 GMT
Server: lighttpd/1.4.28