Getting “Protocol not supported” from setkey: why?

Question

I'm trying to setup an IPsec connection between two Linux systems. I've enabled the kernel options mentioned on the IPsec Howto.

I've setup a setkey script like this:

#! /usr/sbin/setkey -vf
add 192.168.210.1 192.168.210.2 esp 24501 -E 3des-cbc  "123456789012123456789012";
add 192.168.210.1 192.168.210.2 ah 24500 -A hmac-md5 "1234567890123456";

The results come back with "Protocol not supported" (details below). I've double checked the kernel settings using /proc/config.gz: Every one of the options mentioned in the howto has a 'y'. What else might I be missing?

# /flash/ipsec 
sadb_msg{ version=2 type=3 errno=0 satype=3
  len=16 reserved=0 seq=0 pid=23105
sadb_ext{ len=4 type=9 }
sadb_key{ bits=192 reserved=0
  key= 03000500 ff200000 02000000 44f2adbf 00000000 00000000 }
sadb_ext{ len=2 type=1 }
sadb_sa{ spi=24501 replay=0 state=0
  auth=0 encrypt=3 flags=0x00000040 }
sadb_ext{ len=2 type=19 }
sadb_x_sa2{ mode=0 reqid=0
  reserved1=52 reserved2=2 sequence=1076530488 }
sadb_ext{ len=3 type=5 }
sadb_address{ proto=255 prefixlen=32 reserved=0x0000 }
sockaddr{ len=16 family=2 port=0
 44f2adbf  }
sadb_ext{ len=3 type=6 }
sadb_address{ proto=255 prefixlen=32 reserved=0x0000 }
sockaddr{ len=16 family=2 port=0
 b86ae316  }

sadb_msg{ version=2 type=3 errno=93 satype=3
  len=2 reserved=0 seq=0 pid=23105

The result of line 2: Protocol not supported.
sadb_msg{ version=2 type=3 errno=0 satype=2
  len=15 reserved=0 seq=0 pid=23105
sadb_ext{ len=3 type=8 }
sadb_key{ bits=128 reserved=0
  key= 02000000 44f2adbf 00000000 00000000 }
sadb_ext{ len=2 type=1 }
sadb_sa{ spi=24500 replay=0 state=0
  auth=2 encrypt=0 flags=0x00000040 }
sadb_ext{ len=2 type=19 }
sadb_x_sa2{ mode=0 reqid=0
  reserved1=52 reserved2=2 sequence=1076530488 }
sadb_ext{ len=3 type=5 }
sadb_address{ proto=255 prefixlen=32 reserved=0x0000 }
sockaddr{ len=16 family=2 port=0
 44f2adbf  }
sadb_ext{ len=3 type=6 }
sadb_address{ proto=255 prefixlen=32 reserved=0x0000 }
sockaddr{ len=16 family=2 port=0
 b86ae316  }

sadb_msg{ version=2 type=3 errno=93 satype=2
  len=2 reserved=0 seq=0 pid=23105

The result of line 3: Protocol not supported.
#

Answer 1

These kernel config settings do the trick:

CONFIG_INET_XFRM_MODE_TRANSPORT=y
CONFIG_INET_XFRM_MODE_TUNNEL=y