Sun Apr 16, 2006 8:11 am
I see what he is trying to say...
If he pings the local address of his internal interface, from witin winbox, the ping fails. (this packet sould never leave the router it is a ping to an interlal address)
This would be similar to pinging the internal loop back interface on any IP stack.. (127.0.0.1)
If he pings his internal interface from another device inside his NAT ie 192.168.0.4 the ping succeeds...
As this is an internal stack request, it sould never pass any NATs..
It could however pass thru a filter rule if it is interperited as an input. (Router input chain)
I tested this and it will fail under the folowing conditions..
1) place a filter in the input chain for PING and create a drop rule for icmp for all packets orriginating from the router to 0.0.0.0/0 (all addresses). In this case the ping will fail..
2) place a drop rule for ICMP from 0.0.0.0/0 to the router's internal interface. the PING will fail here as well..
Nat should have nothing to do with it as no request to "cross the router" have been made (unless there are mangle rules involved..)
My guess would be an accidental filter rule ment for the external interface that got aplied to the internal interface..
The issue could be a simple typo / oops in a filter rule...
I have made MANY oops in filter rules in my day...
I am a,,, dare I say it ,,, CNE and I mess up with the best of them...
Po boby is nerfect.....
This may be the case, or I may have simply be out of my mind, but I would take another look at the firewall rules and make sure thet there isnt a filter invalved...
PS after more barin farts... I think the later test is closer to the thruth,,
A filter rule filtering the origination of ICMP "from" the router's internal interface is the most likely, as it would allow for the reply to a PING but trap it's own origination of a "grope" request...
Just my two cents worth (US)....
Craig