Step Eight: Testing external MASQ ICMP forwarding
From an internal MASQed computer, ping a static TCP/IP address (NOT a
machine by DNS name) out on the Internet (i.e. ping
152.2.210.81 (this technically the DNS name "metalab.unc.edu" which
is home of MetaLabs' Linux Archive). If this works, it should look something
like the result below and this ultimately shows that ICMP Masquerading is
working properly. (hit Control-C to abort the ping):
-------------------------------------
masq-client# ping 152.2.210.81
PING 12.13.14.15 (152.2.210.81): 56 data bytes
64 bytes from 152.2.210.81: icmp_seq=0 ttl=255 time=133.4 ms
64 bytes from 152.2.210.81: icmp_seq=1 ttl=255 time=132.5 ms
64 bytes from 152.2.210.81: icmp_seq=2 ttl=255 time=128.8 ms
64 bytes from 152.2.210.81: icmp_seq=3 ttl=255 time=132.2 ms
^C
--- 152.2.210.81 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 128.8/131.7/133.4 ms
------------------------------------- |
If this didn't work, again check your Internet connection. Make sure that
the MASQ server itself can ping this address. If this works from the MASQ
server, make sure you are using the simple rc.firewall ruleset and that
you have ICMP Masqurading compiled into the Linux kernel.
Finally, make sure that the ruleset which enables IP MASQ is pointing
to the correct EXTERNAL interface. PPPoE users should use the MASQ servers's
logical PPP interface such as "ppp0" and /NOT/ the physical external interface
like "eth0".
