Network config changes from 12.04 LTS to 14.04 LTS?

[ElToro]

Has something changes in the way network connections are configured from 12.04 LTS to 14.04 LTS?

I have just upgraded a box that I use as a proxy server with two network cards, one connecting to the LAN, the other to the WAN (via a cable modem). After upgrading to 14.04 LTS, the box does not connect on either card. That is, it seems to connect for a minute at startup (clients on the LAN are showing a connection), but then the connections are lost, both to the LAN and to the WAN. Almost looks like some service or other is initialized at startup that blocks the connections... :mad:

If I, after startup, I disable the LAN network connection on the proxy and then enable it again, the Internet is suddenly reachable on the clients. They do not reach the server, however (pinging 10.0.0.1 from a client gives 100% packet loss). At the same time, the WAN seems to be unreachable from the server...:confused: (pinging 8.8.8.8 results in 100% packet loss).

Any suggestions would be most welcome...

Ifconfig gives me the following:


eth0 Link encap:Ethernet HWaddr 00:11:6b:4f:9b:a9
inet addr:192.168.0.201 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::211:6bff:fe4f:9ba9/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:762 errors:0 dropped:0 overruns:0 frame:0
TX packets:806 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:90303 (90.3 KB) TX bytes:104638 (104.6 KB)

eth1 Link encap:Ethernet HWaddr 00:11:6b:4f:9b:cf
inet addr:10.0.0.1 Bcast:10.0.0.255 Mask:255.255.255.0
inet6 addr: fe80::211:6bff:fe4f:9bcf/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8740 errors:0 dropped:0 overruns:0 frame:0
TX packets:996 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:990117 (990.1 KB) TX bytes:136964 (136.9 KB)

eth2 Link encap:Ethernet HWaddr d4:85:64:c4:c0:ef
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:3005 errors:0 dropped:0 overruns:0 frame:0
TX packets:3005 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:339203 (339.2 KB) TX bytes:339203 (339.2 KB)


The rc.local is as follows:


#!/bin/sh -e
#
# rc.local
#

ip addr flush eth0;
ip addr flush eth1;
ifconfig eth0 down;
ifconfig eth1 down;
ifconfig lo down;
ifconfig lo up;
ifconfig eth0 up;
ifconfig eth1 up;
ifconfig eth0 192.168.0.201 netmask 255.255.255.0
ifconfig eth1 10.0.0.1 netmask 255.255.255.0
sysctl net/ipv4/ip_forward=0
iptables -F
iptables -X
iptables -P INPUT DROP
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
#and on again once the policies are set
sysctl net/ipv4/ip_forward=1
#share on mediaserver
#redirect port 80 on lan card and masquerade on wan card :
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
#accept all packets in lo and protect against spoofing :
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -i !lo -s 127.0.0.0/8 -j DROP
iptables -A FORWARD -i !lo -s 127.0.0.0/8 -j DROP
#accept only established input but all output on WAN card
iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i eth1 -j ACCEPT
iptables -A OUTPUT -o eth0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
#iptables -A INPUT -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
#just forget the invalid packets :
iptables -A OUTPUT -o eth0 -m state --state INVALID -j DROP
iptables -A INPUT -i eth0 -m state --state INVALID -j DROP
exit 0

[steveholt2]

Hi,

Did you (or anyone) ever solve this? I am having a very similar problem. I recently upgraded to 14.04.1 LTS, and it no longer seems to handle my network configuration for any amount of time. I have a tuner device (I'm running Myth) connected to eth0 as a Link-Local setup, and I have a wireless card connecting to a wireless router and the internet. When I boot up, everything works fine. I can access the tuner device on the local network at a 169.254.x.x address, and I can get on the internet. However, with a day the system loses the ability to access one or both of the networks. Attempts to ping the router or the device result in "connect: Network is unreachable." Rebooting fixes everything for a few hours. This worked fine on version 12, and since I'm using this machine as a DVR, I kind of need it to be able to stay on the networks.

Anyway, this sounds like it might be the same problem, so I'm very curious if there is a resolution. Thanks.