Can't ping anymore

dicaiopolis · 2015-07-18 04:12:29

Hi everybody,

My ethernet stopped working, so I setup a wifi dongle. I've got access to internet perfectly, but can't ping anymore (which I do sometimes to check my connection). I do:
ping -c3 www.google.com\

and get:

PING www.google.com (64.233.160.105) 56(84) bytes of data.

--- www.google.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2006ms

Do you know what's going on and how to fix it?

Thanks for helping,
D.

teckk · 2015-07-21 19:42:50

PING www.google.com (64.233.160.105) 56(84) bytes of data.

That looks like your DNS server is working.
What do you get from:

ping -c3 64.233.160.105

How about:

ping google.com

I've got access to internet perfectly

What does that mean? You can load web pages ok? And you can't ping google?

You'll get a different IP from ping www.google.com\ and ping google.com

ewaller · 2015-07-21 20:35:36

It could well be that your router is blocking ICMP echo requests. If everything except ping works, that is most certainly the cause (Well, something, not necessarily the router, in the path is blocking ICMP echo request)

fukawi2 · 2015-07-21 22:50:14

Run `mtr google.com` (install mtr from [extra] first of course) and post the output. This should show exactly where the ping packets are going missing.

dicaiopolis · 2015-07-22 14:43:50

teckk wrote:

What do you get from:
ping -c3 64.233.160.105

PING 64.233.160.105 (64.233.160.105) 56(84) bytes of data.

--- 64.233.160.105 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2008ms

teckk wrote:

How about:
ping google.com

It takes too long and gives me no feedback. Had to just cancel it.

teckk wrote:

What does that mean? You can load web pages ok? And you can't ping google?

Yes, I cant load google and any other web page, but can't ping.

oliver · 2015-07-22 14:48:33

dicaiopolis wrote:

Yes, I cant load google and any other web page, but can't ping.

I'm assuming you have an extra 't' in the third word. :-)

I think ewaller has got it - your router is blocking ICMP? Does it work if you bypass the router?

dicaiopolis · 2015-07-22 14:50:45

fukawi2 wrote:

Run `mtr google.com` (install mtr from [extra] first of course) and post the output. This should show exactly where the ping packets are going missing.

It takes forever and gives me no feedback.

dicaiopolis · 2015-07-22 14:54:44

oliver wrote:

dicaiopolis wrote:
Yes, I cant load google and any other web page, but can't ping.
I'm assuming you have an extra 't' in the third word. :-)
I think ewaller has got it - your router is blocking ICMP? Does it work if you bypass the router?

I tried to allow ping using the following commands:

iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
iptables -A INPUT -p icmp --icmp-type echo-reply -j ACCEPT

It didn't work. Could you help me on this? Everything started after my ethernet board stopped working and I installed a ethernet wifi adapter.

Thanks.

ewaller · 2015-07-22 16:48:45

Please verify that you can use the internet, you just cannot ping. (See oliver's post).
Do you have administrative rights on the wireless router?

branch · 2015-07-22 20:17:31

dicaiopolis wrote:

iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
iptables -A INPUT -p icmp --icmp-type echo-reply -j ACCEPT

Is this on the router? If so, both rules need to be set on the FORWARD chain instead of INPUT/OUTPUT.

Also, -A appends the rules to the bottom of the chain after any REJECT's or DROP's, so they won't do anything. Use -I instead to insert the rules at the top.

dicaiopolis · 2015-07-23 00:16:54

ewaller wrote:

Please verify that you can use the internet, you just cannot ping. (See oliver's post).
Do you have administrative rights on the wireless router?

Yes I have access to internet, I just can't ping. How could I verify if I have administrative rights on the router?

Thanks.

dicaiopolis · 2015-07-23 00:18:21

branch wrote:

dicaiopolis wrote:
iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
iptables -A INPUT -p icmp --icmp-type echo-reply -j ACCEPT
Is this on the router? If so, both rules need to be set on the FORWARD chain instead of INPUT/OUTPUT.
Also, -A appends the rules to the bottom of the chain after any REJECT's or DROP's, so they won't do anything. Use -I instead to insert the rules at the top.

Sorry for my ignorance, but how would be the code?

iptables -I FORWARD -p icmp --icmp-type echo-request -j ACCEPT (??)

Thanks for your help.

ewaller · 2015-07-23 00:21:38

dicaiopolis wrote:

How could I verify if I have administrative rights on the router?

Do you own it? Do you have the password to log into it as an administrator?

dicaiopolis · 2015-07-23 19:24:45

ewaller wrote:

dicaiopolis wrote:
How could I verify if I have administrative rights on the router?
Do you own it? Do you have the password to log into it as an administrator?

Yeah, I can sudo it, when necessary.
By the way, sudoing when pinging makes no difference.

Last edited by dicaiopolis (2015-07-23 19:29:48)

ewaller · 2015-07-23 20:03:59

Is there a firewall in the router? That is where you are likely to need to adjust the iptables

branch · 2015-07-23 20:07:47

dicaiopolis wrote:

Sorry for my ignorance, but how would be the code?
iptables -I FORWARD -p icmp --icmp-type echo-request -j ACCEPT (??)
Thanks for your help.

Yes, that looks right. And another for echo-reply. The rule for echo-reply is probably more important as that is what is likely being blocked.

Note that the line you posted above will allow echo-request's through the firewall in both directions, which may not be what you want long-term. Since it seems you can executed commands with root privilege on your router, the output of

sudo iptables-save

could shed light on what the router is actually doing.

dicaiopolis · 2015-07-23 23:36:57

branch wrote:

dicaiopolis wrote:
Sorry for my ignorance, but how would be the code?
iptables -I FORWARD -p icmp --icmp-type echo-request -j ACCEPT (??)
Thanks for your help.
Yes, that looks right. And another for echo-reply. The rule for echo-reply is probably more important as that is what is likely being blocked.
Note that the line you posted above will allow echo-request's through the firewall in both directions, which may not be what you want long-term. Since it seems you can executed commands with root privilege on your router, the output of
sudo iptables-save
could shed light on what the router is actually doing.

Here's the result of sudo iptables-save:

# Generated by iptables-save v1.4.21 on Thu Jul 23 20:35:31 2015
*filter
:INPUT ACCEPT [31:3480]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [30:9776]
-A INPUT -p icmp -m icmp --icmp-type 0 -j ACCEPT
-A FORWARD -p icmp -m icmp --icmp-type 0 -j ACCEPT
-A FORWARD -p icmp -m icmp --icmp-type 8 -j ACCEPT
-A OUTPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
COMMIT

But it's not working anyway.

fukawi2 · 2015-07-23 23:42:01

dicaiopolis wrote:

fukawi2 wrote:
Run `mtr google.com` (install mtr from [extra] first of course) and post the output. This should show exactly where the ping packets are going missing.
It takes forever and gives me no feedback.

You need to look further into this -- what does "no feedback" mean? Just a blank screen? An error message? What? "No feedback" is not normal for the mtr tool.

branch · 2015-07-24 02:51:49

dicaiopolis wrote:

Is this really from your router? Is your router running Arch Linux?

I doubt it. They seem to be ignoring me.

Edit: Moderator foul up

Last edited by ewaller (2015-07-24 03:35:33)

ewaller · 2015-07-24 03:40:55

Branch,
My apologies. I hosed your post. I hit edit, not quote. My moderator privileges allowed me to destroy your post. My browser history did not help. <FacePalm>

dicaiopolis,
Branch's point was that it is incredulous that these were from your router, and that you are playing with your Arch installation when the problem is that the packets are being blocked at you router.

dicaiopolis · 2015-07-24 04:03:21

ewaller wrote:

Branch,
My apologies. I hosed your post. I hit edit, not quote. My moderator privileges allowed me to destroy your post. My browser history did not help. <FacePalm>
dicaiopolis,
Branch's point was that it is incredulous that these were from your router, and that you are playing with your Arch installation when the problem is that the packets are being blocked at you router.

Ok, but this was not happening before my ethernet board died, just after I started using a wifi usb key to deal with that lost... Before, I could ping and I didn't touch the router in between. I'll check it out anyway.

ewaller · 2015-07-24 04:05:36

But, the Ethernet board had been hooked to a wired port (I am assuming), but now you are coming in through the wireless access point.

dicaiopolis · 2015-07-24 05:26:54

ewaller wrote:

But, the Ethernet board had been hooked to a wired port (I am assuming), but now you are coming in through the wireless access point.

It's the router firewall the guilty one. I'm using a Humax router. Do you now how I could allow the ping? I dug the different possibilities, but still can't figure it out. can't guess the right way for doing it.

Thanks for your (everybody's) help.

PS.: since my ethernet board was directly connected to the router, why ping was not blocked anyway?

Last edited by dicaiopolis (2015-07-24 05:28:09)

Arch Linux

#1 2015-07-18 04:12:29

Can't ping anymore

#2 2015-07-21 19:42:50

Re: Can't ping anymore

#3 2015-07-21 20:35:36

Re: Can't ping anymore

#4 2015-07-21 22:50:14

Re: Can't ping anymore

#5 2015-07-22 14:43:50

Re: Can't ping anymore

#6 2015-07-22 14:48:33

Re: Can't ping anymore

#7 2015-07-22 14:50:45

Re: Can't ping anymore

#8 2015-07-22 14:54:44

Re: Can't ping anymore

#9 2015-07-22 16:48:45

Re: Can't ping anymore

#10 2015-07-22 20:17:31

Re: Can't ping anymore

#11 2015-07-23 00:16:54

Re: Can't ping anymore

#12 2015-07-23 00:18:21

Re: Can't ping anymore

#13 2015-07-23 00:21:38

Re: Can't ping anymore

#14 2015-07-23 19:24:45

Re: Can't ping anymore

#15 2015-07-23 20:03:59

Re: Can't ping anymore

#16 2015-07-23 20:07:47

Re: Can't ping anymore

#17 2015-07-23 23:36:57

Re: Can't ping anymore

#18 2015-07-23 23:42:01

Re: Can't ping anymore

#19 2015-07-24 02:51:49

Re: Can't ping anymore

#20 2015-07-24 03:40:55

Re: Can't ping anymore

#21 2015-07-24 04:03:21

Re: Can't ping anymore

#22 2015-07-24 04:05:36

Re: Can't ping anymore

#23 2015-07-24 05:26:54

Re: Can't ping anymore

Board footer