New 2.6.29.4-167.fc11.i586 Can access Internet and ping router -not Internal hosts?

gdotoli · 11-01-2009, 11:23 AM

My linux box can access the internet and ping the router but fails when pinging any host on it's own subnet. I need a little help

64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=2.73 ms
64 bytes from 192.168.0.1: icmp_seq=2 ttl=64 time=2.58 ms
64 bytes from 192.168.0.1: icmp_seq=3 ttl=64 time=2.88 ms
^C
--- 192.168.0.1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2952ms
rtt min/avg/max/mdev = 2.582/2.732/2.884/0.123 ms
[root@gila gdotoli]# ping 192.168.0.5
PING 192.168.0.5 (192.168.0.5) 56(84) bytes of data.
From 192.168.0.32 icmp_seq=2 Destination Host Unreachable
From 192.168.0.32 icmp_seq=3 Destination Host Unreachable
From 192.168.0.32 icmp_seq=4 Destination Host Unreachable

Does anyone have any ideas? There may be a routing or fw issue on the
system, because the Windows systems on this network ping each other fine.

catfish 2.6.29.4-167.fc11.i586 #1 SMP Wed May 27 17:14:37 EDT 2009 i686 i686 i386 GNU/Linux

bertl · 11-01-2009, 01:14 PM

Your network mask may be set incorrectly (should be /24 or 255.255.255.0 probably); do you just use DHCP from your router or is the IP set up manually? Another slight possibility is that it uses the same IP address as one of the other computers.

Have a look at the output of 'ip a l' or 'ifconfig'. It should list something like

Code:

$ ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:24:e8:8e:e1:d0  
          inet addr:192.168.0.x  Bcast:0.0.0.0  Mask:255.255.255.0
          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)
          Memory:f6ae0000-f6b00000 

$ ip a l eth0
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
    link/ether 00:24:e8:8e:e1:d0 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.x/24 scope global eth0

Both tools do the same thing so just use the one you're most comfortable with. Replace 192.168.0.x with the actual IP address of your linux box, of course. The suspected culprit is the '255.255.255.0' with ifconfig or the '/24' with ip.

Since you're using fedora your /etc/sysconfig/network-scripts/ifcfg-eth0 probably needs attention.

Hope that helps. If not, I don't immediately have a clue.

-Bert

catkin · 11-01-2009, 01:43 PM

Quote:

Originally Posted by bertl

Your network mask may be set incorrectly ...

Wouldn't pinging the router/gateway fail in that case?

The problem may be firewalls on the other computers. Are they able to ping each other and this computer?

bertl · 11-01-2009, 02:03 PM

Well if the netmask is set too tight (/25?) he might see some and not see others, but it's not very likely. Windows firewall sounds more likely, yes.

gdotoli · 11-01-2009, 07:28 PM

eth0 Link encap:Ethernet HWaddr 00:E0:4C:F8:BE:C8
inet addr:192.168.0.32 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::2e0:4cff:fef8:bec8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:42318 errors:0 dropped:0 overruns:0 frame:0
TX packets:28691 errors:0 dropped:0 overruns:0 carrier:0
collisions:9824 txqueuelen:1000
RX bytes:49866888 (47.5 MiB) TX bytes:3358412 (3.2 MiB)
Interrupt:16 Base address:0x8000

RX bytes:682832 (666.8 KiB) TX bytes:682832 (666.8 KiB)

Still a problem

[gdotoli@gila ~]$ ping 192.168.0.1
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=3.29 ms
64 bytes from 192.168.0.1: icmp_seq=2 ttl=64 time=2.54 ms
64 bytes from 192.168.0.1: icmp_seq=3 ttl=64 time=2.71 ms
^C
--- 192.168.0.1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2425ms
rtt min/avg/max/mdev = 2.545/2.852/3.296/0.327 ms
[gdotoli@gila ~]$ ping 192.168.0.10
PING 192.168.0.10 (192.168.0.10) 56(84) bytes of data.
From 192.168.0.32 icmp_seq=2 Destination Host Unreachable
From 192.168.0.32 icmp_seq=3 Destination Host Unreachable
From 192.168.0.32 icmp_seq=4 Destination Host Unreachable

bertl · 11-05-2009, 02:14 PM

Have you checked catkin's suggestion? Windows firewalls by default don't always allow ping replies. If you disable the windows firewalls or set them up to allow ICMP echo requests / replies, that might help.