no reply from ping

lord-fu · 06-13-2007, 11:09 AM

Hello and many thanks,

FC6
Linux pbx.X.X 2.6.18-1.2798.fc6 #1 SMP Mon Oct 16 14:37:32 EDT 2006 i686 i686 i386 GNU/Linux

Weird issue I can't seem to solve. I ping google, yahoo, anything outside of our networks and I get no response, the same if someone trys to ping this machine where routing is involved. In other words I can ping this machine from within this network but if routing is involved, nothing.

Code:

[root@pbx ~]# ping google.com
PING google.com (64.233.167.99) 56(84) bytes of data.
[root@pbx ~]# ping yahoo.com
PING yahoo.com (66.94.234.13) 56(84) bytes of data.

Will just sit there and never advance to show a reply.

Quote:

[root@pbx ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.0.0.0 * 255.255.0.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth1
192.168.0.0 * 255.255.0.0 U 0 0 0 eth1
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth1

Code:

[root@pbx ~]# traceroute google.com
traceroute to google.com (72.14.207.99), 30 hops max, 40 byte packets
 1  * * *
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  * * *
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

Code:

[root@pbx ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:04:75:90:7B:2E
          inet addr:10.0.5.1  Bcast:10.0.255.255  Mask:255.255.0.0
          inet6 addr: fe80::204:75ff:fe90:7b2e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:292511 errors:0 dropped:0 overruns:1 frame:0
          TX packets:291397 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:48121841 (45.8 MiB)  TX bytes:160269305 (152.8 MiB)
          Interrupt:193 Base address:0x6000

eth1      Link encap:Ethernet  HWaddr 00:07:E9:3F:0E:04
          inet addr:192.168.5.1  Bcast:192.168.255.255  Mask:255.255.0.0
          inet6 addr: fe80::207:e9ff:fe3f:e04/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:396885 errors:0 dropped:0 overruns:0 frame:0
          TX packets:125263 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:382233870 (364.5 MiB)  TX bytes:19768215 (18.8 MiB)
          Base address:0x28c0 Memory:fb040000-fb060000

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:16436  Metric:1
          RX packets:200 errors:0 dropped:0 overruns:0 frame:0
          TX packets:200 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:313874 (306.5 KiB)  TX bytes:313874 (306.5 KiB)

I have entered runlevel 5 and used the gui tool to disable firewall, and setenforce 0, and still problem persists. We use local DNS servers.

Quote:

[root@pbx ~]# cat /etc/resolv.conf
nameserver 192.168.3.1
nameserver 192.168.3.2

I really am at a loss here, any ideas? Am I missing something? I will gladly provide more info if asked.

MTIA

[edit] I just saw now in the output of that ifconfig up there on interface etho this line with an overrun
RX packets:292511 errors:0 dropped:0 overruns:1 frame:0 <- bad?

tomcdyer · 06-13-2007, 12:34 PM

You have given a lot of info.

One question, Do you have any proxy servers running? As i've had problems with network apps and proxies.

What i can say is that your DNS seems to be working (as it translated google.com to 64.233.167.99).

Also if i am correct, your gateway seems to be on a netmask of 0.0.0.0?
and you have 2 IP addresses for eth0 (nothing odd there but still could be a problem). I assume the 192.168.0.0 is for the internet and most networking. Have you tried manually setting these addresses and not using 192.168.0.0 try 192.168.0.22 or something above 10.

Hope this is helpful

DotHQ · 06-13-2007, 12:37 PM

I've had this same problem when /etc/sysconfig/iptables was set not to accept pings, and iptables is instructed to drop the packet. When that happens you get no response, which sounds like your problem.

To test this theory do a:
service iptables stop
Then see if you get any different results with your ping.

GregLee · 06-13-2007, 12:49 PM

Your ip addresses suggest you are on a local lan, so maybe you're behind a router? The router may have it's own firewall which is blocking ping. (My router does have a firewall, and it does block ping in and out of the local lan by default.)

lord-fu · 06-13-2007, 01:10 PM

@tomcdyer Thank you for your response.

Quote:

You have given a lot of info.

The more the better I suppose.

Quote:

One question, Do you have any proxy servers running?

No.

Quote:

What i can say is that your DNS seems to be working (as it translated google.com to 64.233.167.99).

This is correct.

Quote:

Also if i am correct, your gateway seems to be on a netmask of 0.0.0.0?

I did not set the netmask of this gateway. Just said, here is my gateway. I manually set information in /etc/sysconfig/network-scripts/ifcfg-ethx

Quote:

I assume the 192.168.0.0 is for the internet and most networking. Have you tried manually setting these addresses and not using 192.168.0.0 try 192.168.0.22 or something above 10.

192.168.0.0 is the network. The out put above shows 192.168.5.1 as the assigned address for this interface. And yes 192.168.x.x network talks to the outside world.

@DotHQ Thank you for your reply.

Quote:

To test this theory do a:
service iptables stop
Then see if you get any different results with your ping.

As I posted above, I have turned off the firewall. And policy's.

@GregLee Thank you for your reply.

Quote:

Your ip addresses suggest you are on a local lan, so maybe you're behind a router? The router may have it's own firewall which is blocking ping. (My router does have a firewall, and it does block ping in and out of the local lan by default.)

This is true and we are behind a firewall, however it is not blocking pings, the router allows all out from LAN and is a stateful packet filter. There are 75+ other servers behind our perimiter firewall and they all can ping out and get replies. This ipaddress was in use by another machine untill yesterday, when I rebuilt this one in question and assigned it the old machines ip. The old machine is down and off network right now. SO this rules out conflicts.

Any other ideas guys/girls?
MTIA

DotHQ · 06-13-2007, 01:15 PM

Does the router firewall accept pings for all IP addresses or just a specific range? If range then perhaps the new IP address is out of that range.

lord-fu · 06-13-2007, 01:25 PM

@DotHQ Thanks again for your reply
No ranges.
This ip address was used until yesterday, when it was given to this machine. The machine that owned the ip address yesterday had no networking hiccups of any kind.

Road_map · 06-13-2007, 01:53 PM

Quote:

Originally Posted by lord-fu

Code:

eth0      Link encap:Ethernet  HWaddr 00:04:75:90:7B:2E
          inet addr:10.0.5.1  Bcast:10.0.255.255  Mask:255.255.0.0


eth1      Link encap:Ethernet  HWaddr 00:07:E9:3F:0E:04
          inet addr:192.168.5.1  Bcast:192.168.255.255  Mask:255.255.0.0

Why netmask is 255.255.0.0? It should be 255.255.255.0.

lord-fu · 06-13-2007, 02:03 PM

@Road_map

Quote:

Why netmask is 255.255.0.0? It should be 255.255.255.0.

Not at all. Our netmask is exactly as it should be. We run 192.168.x.x and 10.0.x.x as displayed by the braodcast range as well.

Here is my interface setup info.

Code:

[root@pbx network-scripts]# cat ifcfg-eth0
# 3Com Corporation 3c905C-TX/TX-M [Tornado]
DEVICE=eth0
BOOTPROTO=none
BROADCAST=10.0.255.255
HWADDR=00:04:75:90:7B:2E
IPADDR=10.0.5.1
NETMASK=255.255.0.0
NETWORK=10.0.0.0
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes

Code:

[root@pbx network-scripts]# cat ifcfg-eth1
# Intel Corporation 82540EM Gigabit Ethernet Controller
DEVICE=eth1
BOOTPROTO=none
BROADCAST=192.168.255.255
HWADDR=00:07:E9:3F:0E:04
IPADDR=192.168.5.1
NETMASK=255.255.0.0
NETWORK=192.168.0.0
ONBOOT=yes
GATEWAY=192.168.0.1
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes

As someone asked earlier why we are setup for an ipv6 address, I am not sure why it shows I have set it to no under /etc/sysconfig/network and in the above files. I am not sure i that plays a role in this or not.

I agree with those that are suspecting firewall, but I have turned off that suspect. I have double checked to make sure the perimeter firewall is not blocking, it absolutely is not. I really am stumped.

MTIA

lord-fu · 06-13-2007, 03:37 PM

OK, got it sorted out. It was at the router. We used to have(until a week or so ago) a T1 line which I did not know had statically configured routes for this machine(IP).

Thanks to all for your help and ideas.

tomcdyer · 06-13-2007, 04:18 PM

Glad you sorted it out