pinging same host on the internet from two different LAN stations

[Daniel Hartmeier]

On Tue, Jul 26, 2005 at 05:58:18AM -0700, Pejman Moghadam wrote:

> I have one FreeBSD 5.4 router/firewall box in my LAN that do NAT with PF.
> The problem is I can't ping the same machine on the internet from two or more different machines
> on my LAN at the same time. only one of my LAN clients can ping that target, and pinging that
> target from another station is possible only when i stop pinging from first client.
> Is there any way or any tool that ICMP portmapping allows simultaneous connections to external
> targets from multiple machines from the LAN?

I don't believe you have actually tried this.

>From one workstation (10.1.1.20)

  $ ping 199.185.137.3
  64 bytes from 199.185.137.3: icmp_seq=0 ttl=235 time=218.693 ms
  64 bytes from 199.185.137.3: icmp_seq=1 ttl=235 time=211.615 ms
  [...]

At the same time, from another workstation (10.2.2.11)

  $ ping 199.185.137.3
  64 bytes from 199.185.137.3: icmp_seq=0 ttl=235 time=195.604 ms
  64 bytes from 199.185.137.3: icmp_seq=1 ttl=235 time=194.387 ms

On the gateway which does NAT for both

  # pfctl -ss | grep icmp
  kue0 icmp 10.1.1.20:354 -> 62.65.145.30:354 -> 199.185.137.3:354 0:0
  kue0 icmp 10.2.2.11:19057 -> 62.65.145.30:19057 -> 199.185.137.3:19057 0:0

What looks like port numbers in the state is the ICMP ID, a number
chosen randomly for one ping invokation. pf uses this to dispatch
incoming replies from the external host to the appropriate internal
host.

Daniel