How to route ICMP packets...

  • Thread starter Thread starter S Fisher
  • Start date Start date
S

S Fisher

Hi,

Need an expert to answer this one!

I have an NT 4 box operating as an internet gateway running CProxy
(www.youngzsoft.com) as a caching proxy server for a small network of Win 2K
machines.
All the proxies work fine with no problems.

I want to be able to use PING & TRACERT commands on one of the local
machines and can't figure out how to route the ICMP packets through the
gateway.
I presume I would need to add a route (using route.exe ?) on the gateway
machine but don't know what it should be.
There is also a network option on NT 4 to allow IP forwarding but I'm not
sure what that is for.

Can anyone help me?! please!

Network is configured 192.168.0.x/255.255.255.0 & gateway machine is
192.168.0.254

Regards to the group,

Sholto.
 
I doubt it is a routing issue. It probably is an issue with the proxy server
configuration. Any traffic that is not destined for the local network will go through
the default gateway if it is allowed to unless there is a static route in the routing
table which there would not be by default. I am not familiar with Cproxy but on
Microsoft ISA server you can allow or block ICMP outbound traffic at the gateway.
Check the documentation for Cproxy. --- Steve
 
Proxies don't forward (Route). You will need to have a helper service on the proxy system which can then ping ot trace route on your behalf enabled.
 
Caching Proxys typically follow the CERN Compliant HTTP Proxy standard and
do not "process" ICMP on behalf of clients behind it. They only provide
HTTP, HTTPS(port 443 only), FTP(one direction, read-only, http
encapsulated), and Gopher.

MS's ISA Server has a "SecureNAT Service" that allows ICMP, but only works
if the Clients are configured as SecureNAT Client. The other services of
ISA do not "process" ICMP.

MS's older Proxy1 & Proxy2 did not ever "process" ICMP. It was intentional
and by design.
 
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