How to ping when behind a proxy?

31

7

I am using an HTTP proxy server to connect to the internet.

Because of that my pings are not working

ping www.google.com

says Unreachable Host

How can I configure ping to use the HTTP proxy?

Lazer

Posted 2010-08-13T09:20:16.533

Reputation: 13 841

It may be helpful to know what setup you are using? Is this a linux server with squid and iptables for example? – Tim Alexander – 2010-08-13T09:51:29.387

Answers

35

In general you can't. ping needs a direct network connection on the IP level to do its work. A proxy works on a higher layer of the TCP/IP network model, where there is no direct access to the IP protocol.

You would need to somehow circumvent the proxy (change firewall settings, use a VPN, ...). Whether this is possible (and allowed) depends on your network configuration, but it's probably not possible.

As a workaround, there are many web-based ping services available (search for "web-based ping"). These will work.

sleske

Posted 2010-08-13T09:20:16.533

Reputation: 19 887

Web-based pings cannot be used to test the latency of my own connection, as they are initiated from the server. Maybe some implementation of ping in java that runs in the browser. – Jose Gómez – 2015-09-08T08:14:49.623

While the ICMP protocol operates on ISO/OSI layer 3, the ping utility operates on layer 7. To quote my CS teacher, ping is a 3-7 hybrid. It may well be possible that the layer 7 part is capable of proxy handling. This would explain why my answer to this question works (at least for me).

– s3lph – 2015-09-13T18:56:18.100

@the_Seppi: Interesting, I've never heard of ping being layer 7. Do you have any pointers for further reading? – sleske – 2015-09-13T20:28:36.787

7

You may try this,But first you have to install curl.

http_proxy=http://<proxy_username>:<proxy_password>@<your_proxy_server>:<your_proxy_port>  curl -I http://google.com/

Ishant Mrinal

Posted 2010-08-13T09:20:16.533

Reputation: 221

24this is not PING. – törzsmókus – 2015-02-24T20:42:54.163

2or you can use curl -x 'http://<proxy_username>:<proxy_password>@<your_proxy_server>:<your_proxy_port>' – phyatt – 2017-12-07T18:20:57.480

1@törzsmókus: But it is likely a good answer to the source of the question ... to test, if some server is available and working! – Andreas Dietrich – 2018-11-19T09:51:18.620

1The question was, How can I configure ping to use the HTTP proxy? This post by @Ishant Mrinal does not answer that. If someone asks a question [How] to test, if some server is available and working [from behind a proxy?], feel free to add this answer, and also link to it in the comments of this question. – törzsmókus – 2018-11-19T12:05:32.130

1@törzsmókus - You are correct in that the answer does not address strictly the question. It may be the case that the OP (or other readers searching for a similar idea, as myself) asks this while not being specifically interested in using ping, but in using it only as a quick way to test if a given PC is reaching the outside network (as another use, besides the comment by Andreas Dietrich). I found this answer useful (the main idea behind SO), and so did at least other 8 users. – sancho.s Reinstate Monica – 2019-01-08T06:38:26.043

1

As others noted, ping doesn't work through proxy.

But you can use utility httping for that. It sends a HEAD request (by default) to a web server and measures the time it took to get a response.

Example:

httping -x 192.68.1.12:1080 -g http://google.com

Example output:

➜  ~ httping -g http://google.com -c 3
PING google.com:80 (/):
connected to 64.233.165.113:80 (313 bytes), seq=0 time= 38.49 ms 
connected to 64.233.165.101:80 (313 bytes), seq=1 time= 66.94 ms 
connected to 64.233.165.100:80 (313 bytes), seq=2 time= 40.79 ms 
--- http://google.com/ ping statistics ---
3 connects, 3 ok, 0.00% failed, time 3162ms
round-trip min/avg/max = 38.5/48.7/66.9 ms

Where:

  • -x - Address of a proxy server, port is optional
  • -g - URL to send a request to

Other useful options:

  • -5 - Use SOCKS5. Should be put after the -x option, i.e.:

    httping -x localhost:1080 -5 -g http://google.com
    
  • -c - How many probes to send before exiting. Infinite by default.
  • -G - Do a GET request instead of a HEAD request. That means that also full page/file will be transferred. Note that in this case you're no longer measuring the latency! Useful for testing actual websites.

Be noticed that the time measured also includes the latency introduced by the proxy server itself.


The utility is available through a number of repositories for different OS'es and Linux distros:

Ubuntu:

sudo apt install httping

Alpine:

sudo apk add httping

macOS with Homebrew:

brew install httping

As another example, I used httping to estimate latency of my connection to Tor network through Tor proxy:

httping -x localhost:9050 -5 -g http://google.com

The only option I wish httping had is the ability to ask SOCKS5 proxy for domain name resolution, instead of doing it on its own, which is a more secure way with Tor.


Here is a link to the author's website:

https://www.vanheusden.com/httping/

Bogdan Kondratov

Posted 2010-08-13T09:20:16.533

Reputation: 11