Hi, I have a problem with ipsec setup on my 2 box one of them is rhel4 Update 3 and other one is fedora core 4 I get the following error: rhel 4.3 box: Jul 12 19:07:32 racoon: INFO: NAT detected -> UDP encapsulation (ENC_MODE 1->61443). Jul 12 19:07:32 racoon: INFO: NAT detected -> UDP encapsulation (ENC_MODE 1->61443). Jul 12 19:07:32 racoon: INFO: Adjusting my encmode UDP-Tunnel->61441 Jul 12 19:07:32 racoon: INFO: Adjusting peer's encmode UDP-Tunnel->61441 Jul 12 19:07:32 racoon: INFO: Adjusting my encmode UDP-Tunnel->61441 Jul 12 19:07:32 racoon: INFO: Adjusting peer's encmode UDP-Tunnel->61441 Jul 12 19:07:32 racoon: ERROR: libipsec failed send update (No algorithm specified) Jul 12 19:07:32 racoon: ERROR: pfkey update failed. Jul 12 19:07:32 racoon: ERROR: failed to process packet. Jul 12 19:07:32 racoon: ERROR: phase2 negotiation failed. fedora 4: Jul 12 21:08:12 searchdb15 racoon: INFO: Adjusting my encmode UDP-Tunnel->Tunnel Jul 12 21:08:12 searchdb15 racoon: INFO: Adjusting peer's encmode UDP-Tunnel(61443)->Tunnel(1) Jul 12 21:08:12 searchdb15 racoon: INFO: Adjusting my encmode UDP-Tunnel->Tunnel Jul 12 21:08:12 searchdb15 racoon: INFO: Adjusting peer's encmode UDP-Tunnel(61443)->Tunnel(1) Jul 12 21:08:12 searchdb15 racoon: ERROR: libipsec failed send update_nat (No algorithm specified) Jul 12 21:08:12 searchdb15 racoon: ERROR: pfkey update failed. Jul 12 21:08:12 searchdb15 racoon: ERROR: failed to process packet. Jul 12 21:08:12 searchdb15 racoon: ERROR: phase2 negotiation failed. The error is obvious: libipsec failed send update_nat (No algorithm specified) but where should I define this? my configuration is as follows: sainfo anonymous { pfs_group modp768; encryption_algorithm 3des; authentication_algorithm hmac_md5; compression_algorithm deflate; } include "/etc/racoon/XX.XXX.XXX.conf"; XX.XXX.XXX.conf: remote XX.XXX.XXX { exchange_mode main; nat_traversal on; proposal { encryption_algorithm 3des; hash_algorithm md5; authentication_method pre_shared_key; dh_group modp1024; } } By the way ipsec-tools version on fedora is ipsec-tools-0.6.4-1.1 and on rhel ipsec-tools-0.3.3-6.rhel4.1 -- Omer Faruk Sen http://www.faruk.net