pen-testing client, question on gateway and network topology
 

Hello all,
Today i was pen-testing my clients n/w.
It has around 60 hosts...lets suppose 1-60.
ICMP packets are not reaching to any machine except .15. They all are reaching upto .78 (different subnet), which is of ISP.
But for machine .15 ICMP are crossing .78--->.234--->.15(host)
This .234 is also of ISP.
Networks .1 and .2 machines seems to be router (telnet is open), but all ports on .15 are filtered.
Then what is the gateway of this n/w ???

If .1 or .2 are gateways then why the packets to .15 are being delivered directly to .15 and not routing from .1 or .2 ???
Is .15 the gateway ?
Where is the firewall ?


regards