Arch Linux

guardkuo

Member

Registered: 2012-12-21

Posts: 2

I cannot connect to internet after I update system.

Hi,

I update my system a few day ago (use systemd to replace rc.d) and I cannot connect internet. I guess my router table is broken, but I cannot find any problem.

I use ping to try some IP. And I find I connect to local machine only.
Do I miss some configuration ?
--------------------------------------------------------------
[~]ping -c 3 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.

--- 8.8.8.8 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2000ms

[~]$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.27.13.254   0.0.0.0         UG    204    0        0 eth2
10.10.12.0      0.0.0.0         255.255.255.0   U     0      0        0 eth1
172.27.12.0     0.0.0.0         255.255.254.0   U     204    0        0 eth2
[ ~]$ ping 172.27.13.254
PING 172.27.13.254 (172.27.13.254) 56(84) bytes of data.

--- 172.27.13.254 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 999ms

[ ~]$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.27.13.254   0.0.0.0         UG    204    0        0 eth2
10.10.12.0      0.0.0.0         255.255.255.0   U     0      0        0 eth1
172.27.12.0     0.0.0.0         255.255.254.0   U     204    0        0 eth2
[~]$ ping 172.27.13.254
PING 172.27.13.254 (172.27.13.254) 56(84) bytes of data.

--- 172.27.13.254 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 999ms

--- 172.27.13.254 ping statistics ---
41 packets transmitted, 0 received, 100% packet loss, time 40131ms

brebs

Member

Registered: 2007-04-03

Posts: 3,742

Re: I cannot connect to internet after I update system.

I'm not sure about that Genmask, so try this to make the route to your router explicit:

route add -net 172.27.13.254 netmask 255.255.255.255 dev eth2

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,690

Re: I cannot connect to internet after I update system.

You've two interfaces.  Could you tell us a bit more about your network's topography? 

Which interface to use expect connect to the Internet?  Where does the other network go?  (i.e. are you trying to be a bridge or provide NAT ?)

Also, as a sanity check, what do iip link and  ip addr report?

---

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---
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guardkuo

Member

Registered: 2012-12-21

Posts: 2

Re: I cannot connect to internet after I update system.

Hi,

I have 2 network interface.
The eth1 is for test only. It is connected to a 8 port LAN switch, and there are 2 NAS connected to this switch.

I use eth2 to connect to internet, for example, update system. I try to disable eth1, but it is still not work.

ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:e0:81:27:32:61 brd ff:ff:ff:ff:ff:ff
    inet 10.10.12.50/24 brd 10.10.12.255 scope global eth1
    inet6 fe80::2e0:81ff:fe27:3261/64 scope link
       valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:07:e9:01:a1:36 brd ff:ff:ff:ff:ff:ff
    inet 172.27.12.23/23 brd 172.27.13.255 scope global eth2
    inet6 fe80::207:e9ff:fe01:a136/64 scope link
       valid_lft forever preferred_lft forever

ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN mode DEFAULT
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000
    link/ether 00:e0:81:27:32:60 brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
    link/ether 00:e0:81:27:32:61 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
    link/ether 00:07:e9:01:a1:36 brd ff:ff:ff:ff:ff:ff

Last edited by guardkuo (2012-12-22 10:52:35)