I have an IOS router (12.4) that I am adding a VPN tunnel to. There are other active tunnels on this router (both ezvpn, site-to-site and GRE). Everything appears to be working on both sides regarding phase 1/phase 2 negotiation, but packets that are being send from the PIX to the IOS router, while being encrypted and encapsulated do not appear to be being decrypted on the IOS end.
I have spent many, many hours on trying to diagnose this and I am struggling - would appreciate any help.
Show crypto isakmp sa on the IOS shows (IPs changed for security):
1.1.1.1 2.2.2.2 QM_IDLE 4 0 ACTIVE
Show crypto ipsec sa on the IOS shows (IPs changed for security):
local ident (addr/mask/prot/port): (10.13.39.0/255.255.255.0/0/0)
remote ident (addr/mask/prot/port): (172.16.50.0/255.255.255.0/0/0)
current_peer 2.2.2.2 port 500
PERMIT, flags={origin_is_acl,}
#pkts encaps: 408, #pkts encrypt: 408, #pkts digest: 408
#pkts decaps: 0, #pkts decrypt: 0, #pkts verify: 0
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0
#pkts not decompressed: 0, #pkts decompress failed: 0
#send errors 108, #recv errors 0
local crypto endpt.: 1.1.1.1, remote crypto endpt.: 2.2.2.2
path mtu 1500, ip mtu 1500, ip mtu idb FastEthernet0/0
current outbound spi: 0xBC3A7FC9(3157950409)
inbound esp sas:
spi: 0x2DF17FA(48175098)
transform: esp-3des esp-sha-hmac ,
in use settings ={Tunnel, }
conn id: 3003, flow_id: FPGA:3, crypto map: CustVPN
sa timing: remaining key lifetime (k/sec): (4553489/2310)
IV size: 8 bytes
replay detection support: Y
Status: ACTIVE
inbound ah sas:
inbound pcp sas:
outbound esp sas:
spi: 0xBC3A7FC9(3157950409)
transform: esp-3des esp-sha-hmac ,
in use settings ={Tunnel, }
conn id: 3004, flow_id: FPGA:4, crypto map: CustVPN
sa timing: remaining key lifetime (k/sec): (4553463/2310)
IV size: 8 bytes
replay detection support: Y
Status: ACTIVE
outbound ah sas:
outbound pcp sas:
I am focusing in on the decapsulation/decryption and on why it is not happening. Everything appears to be working on the PIX end.
show crypto isakmp sa on the PIX shows (IPs changed for security):
Active SA: 1
Rekey SA: 0 (A tunnel will report 1 Active and 1 Rekey SA during rekey)
Total IKE SA: 1
1 IKE Peer: 1.1.1.1
Type : L2L Role : initiator
Rekey : no State : MM_ACTIVE
show crypto ipsec sa on the PIX shows (IPs changed for security):
Crypto map tag: outside_map, seq num: 120, local addr: 2.2.2.2
access-list outside_cryptomap_120 permit ip 172.16.50.0 255.255.255.0 10.13.39.0 255.255.255.0
local ident (addr/mask/prot/port): (172.16.50.0/255.255.255.0/0/0)
remote ident (addr/mask/prot/port): (10.13.39.0/255.255.255.0/0/0)
current_peer: 1.1.1.1
#pkts encaps: 1030, #pkts encrypt: 1030, #pkts digest: 1030
#pkts decaps: 322, #pkts decrypt: 322, #pkts verify: 322
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 1030, #pkts comp failed: 0, #pkts decomp failed: 0
#pre-frag successes: 0, #pre-frag failures: 0, #fragments created: 0
#PMTUs sent: 0, #PMTUs rcvd: 0, #decapsulated frgs needing reassembly: 0
#send errors: 0, #recv errors: 0
local crypto endpt.: 2.2.2.2, remote crypto endpt.: 1.1.1.1
path mtu 1500, ipsec overhead 58, media mtu 1500
current outbound spi: 02DF17FA
inbound esp sas:
spi: 0xBC3A7FC9 (3157950409)
transform: esp-3des esp-sha-hmac none
in use settings ={L2L, Tunnel, }
slot: 0, conn_id: 36, crypto-map: outside_map
sa timing: remaining key lifetime (kB/sec): (4274981/1824)
IV size: 8 bytes
replay detection support: Y
outbound esp sas:
spi: 0x02DF17FA (48175098)
transform: esp-3des esp-sha-hmac none
in use settings ={L2L, Tunnel, }
slot: 0, conn_id: 36, crypto-map: outside_map
sa timing: remaining key lifetime (kB/sec): (4274939/1824)
IV size: 8 bytes
replay detection support: Y
Everything seems ok to me but the IOS is not decrypting. The other tunnels on the system are working fine. Debugs do not show any errors.
