Hello,

I have an internet connection on a computer with windows, the linux takes the internet from it with a proxy, with the program winproxy, when I ping I cant use a proxy, and therefor I cant ping because without a proxy, there is no internet,so, how can I ping using a proxy server ?

Hi ,

Let me clarify a few things first ....
When ur using proxy ( i assume its squid) ur using http protocol whereas when pinging someone ur using icmp protocol .... u got the picture ? u cant ping from a proxy unless under below mentioned circumstances :

1. Ur proxy does ip forwarding .... that is simply forwards ur request to the external server (and not proxy/cache ) without bringing http protocol into picture.

2. U can use ip masquerading fetaure ..... u might need to downlaod appropriate ipmasquerade module to do that.

ipforwarding is done certain modification in one of the files in /proc directory whereas for ipmasquerade u need to go on internet and read some docs .

Hope this puts u in right track.

Regards ,
Xanthium.

so, how can I share icmp ?

Hi ,

I guess u didnt take efforts to study more about ipmasquerade and ipforwarding .

Assuming ur new to linux community i will try to help (If i can).

As i told with ip forwarding u dont need any proxy installed on ur linux box. Ur clients simply need to mention ur linux box as the default gateway and ur linux box will simply forward the requests
to external world.... the downside side is that the http pages wont be cached and users might use heavy apps like napster, icq and so on ......

IP forwarding on RedHat :
echo "1" > /proc/sys/net/ipv4/ip_forward

NOTE: Check for the exsistence of the file and then put the command in any of the startup files. Also i dont know how to do this on non RedHat machines.


Now u should use ip masquerade software. It supports ICMP masquerade.
so whenever ur clients send icmp packet ( PING) it will substitute its own address insted of the client and vice versa. Hope this clears.

Still in doubt try searching internet for what i have mentioned above. Try reading ip masquerading howto on www.linuxdoc.org.


OR IF NOTHING WORKS ------>
check out a software called ipautofw .... i havent tried it myself so
try ur luck.


Feel free to contact if u arent able to ping ..... but try reading the online docs about ipmasquerading first and try out things urself.


Regards,
Xanthium.

Hi ,

I guess this is rather embarassing but i how to admit that i replied hastily to ur post. Ur getting ur internet from a windows running winproxy ( and i thought it was the other way around).

SORRY SIR but there is no way ur linux box or any other client can ping external world with winproxy as the proxy s/w.WinProxy will not allow ICMP packets - including ping and tracert - to pass through the proxy in either direction. However WinProxy allows telnet to non-standard ports.


Sorry for the wrong info i provided.


Thanks.

Got the same question as Mega^Deth.
So does anyone knows which proxy does have this feature ?
I looked at several proxies at Tucows but none of them mention icmp.

xanthium Hello,

you already told me I cant do it with winproxy,
so with which software can I ?

Hi ,

Iam not much into windows based environment. But i guess You may want to try the HummingBird SOCKS Client, AutoSOCKS, or SocksCAP, which are firewall traversal applications that transparently "socks-ify" Windows-based TCP/IP applications, letting them work behind proxy servers.
As such this provide u with "socks-ified" ping utility which u can use to ping outside world ..... however u CANNOT use the ping utility provided with Linux or Windows. You need to use
the "socks-ified" ping utility ONLY.

or maybe you can try send ICMP packets on and Internet Sharing Solution using Network Address Translation (NAT). WinGate 4.0.1 with the ENS plug-in makes use of NAT and will allow the client computers to Ping. I guess previously i had talked about ipmasquerading which is similar to NAT. Try reading about NATting on the internet.


Got my point ?


Regards,
Xanthium.

Hi ,

I forgot to mention that i do not know of any proxy which allows icmp packets to traverse. In my previous post i only mentioned applications (socks-ified ) that ur client can use to ping the outside world .... they are by no way acting as server . Hope iam clear.

Regards,
Xanthium.

Err, linuxquestions.org? Am I in the right forum here? No offence mega^deth, but I use Linux because Windows proxies never fit my needs. There are MANY different ways to achieve icmp forwarding under Linux. If you don't want to take the plunge, that's understandable, but given the security and control advantages of a linux solution, and the fact that you are posting to a linux forum, I would suggest some open source alternatives:

ipchains
iptables
squid
search http://www.google.com/linux or http://freshmeat.net for proxy servers

Mega, thought you liked to know this, I setup connection sharing on my xp box and put my redhat box on dhcp, I can do anything from browsing to pinging. There was no need to setup a proxy in mozilla or whatever.

Its the same as IP forarding in linux !!!!!! except u dont cache the http.

regards,
Xanthium.