<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial, helvetica, sans-serif;font-size:10pt"><div>Hi all,</div><div style="font-family:arial, helvetica, sans-serif;font-size:10pt"><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><div style="font-family:arial, helvetica, sans-serif;font-size:10pt;"><div> I have a question regarding IPSec processing on Security Gateway (SEG). Consider a network as below.</div><div><br></div><div><br></div><div>Host A ----------------------Gateway --------------------Gateway--------------------Host B</div><div> 1 2</div><div><br></div><div>If suppose the IPSec
tunnel is required to be initiated from Host A to Host B, I was wondering how will the IPSec packets be </div><div>processed on route to Host B. Lets say its ESP in tunnel mode. The packet from Host A to Gateway 1
would appear as below</div><div><br></div><div><br></div><div>New IP | ESP | Orig IP | UDP</div><div><br></div><div>My question is, when this packet is received on Gateway 1, will the ESP header of this packet be decrypted to form another ESP</div><div>and the resulting packet going out would appear like</div><div><br></div><div>New IP | ESP | Orig IP | UDP</div><div><br></div><div><br></div><div>OR </div><div><br></div><div>Or its the entire IP packet received is given as input to form another ESP packet.. And the resulting packet going out would appear like</div><div><br></div><div>New IP | ESP | IP | ESP | Orig IP | UDP</div><div> |<-----------hashed---------> |</div><div><br></div><div><br></div><div>I hope you have got my question. Please correct me If am wrong at any place.. And would appreciate if you could guide me to
some </div><div>specification that explains the IPSec Processing on Gateways.</div><div><br></div><div><br></div><div>Many Thanks,</div><div>Bharat</div><div><br></div><div><br></div><div style=""></div>
</div><br>
<meta http-equiv="x-dns-prefetch-control" content="on"></div></div><div style="position:fixed"></div>
</div><br>
</body></html>