如何配置 IPSEC 密鑰更新的提議

我有一個通過 IPSEC (strongswan) 成功執行的 VPN 連接。但是，每天至少有一次連接中斷。我認為這與重新加密有關，請參閱日誌：

Aug 25 02:34:25 myserver charon: 09[KNL] creating rekey job for CHILD_SA ESP/0xcbd335d0/xxx.xxx.xxx.xxx
Aug 25 02:34:25 myserver charon: 10[IKE] establishing CHILD_SA infonline_datapool{2} reqid 1
Aug 25 02:34:25 myserver charon: 12[CFG] received proposals: ESP:AES_CBC_256/HMAC_SHA2_256_128/MODP_2048/NO_EXT_SEQ
Aug 25 02:34:25 myserver charon: 12[CFG] configured proposals: ESP:AES_CBC_256/HMAC_SHA1_96/MODP_2048/NO_EXT_SEQ, ESP:AES_CBC_128/AES_CBC_192/AES_CBC_256/HMAC_SHA2_256_128/HMAC_SHA2_384_192/HMAC_SHA
2_512_256/HMAC_SHA1_96/AES_XCBC_96/NO_EXT_SEQ
Aug 25 02:34:25 myserver charon: 12[IKE] no acceptable proposal found
Aug 25 02:34:25 myserver charon: 12[IKE] failed to establish CHILD_SA, keeping IKE_SA
Aug 25 02:34:25 myserver charon: 12[IKE] sending DELETE for ESP CHILD_SA with SPI cbd2f4c3
Aug 25 02:34:25 myserver charon: 11[IKE] CHILD_SA rekeying failed, trying again in 10 seconds
Aug 25 02:34:35 myserver charon: 15[IKE] establishing CHILD_SA infonline_datapool{3} reqid 1
Aug 25 02:34:35 myserver charon: 06[CFG] received proposals: ESP:AES_CBC_256/HMAC_SHA2_256_128/MODP_2048/NO_EXT_SEQ
Aug 25 02:34:35 myserver charon: 06[CFG] configured proposals: ESP:AES_CBC_256/HMAC_SHA1_96/MODP_2048/NO_EXT_SEQ, ESP:AES_CBC_128/AES_CBC_192/AES_CBC_256/HMAC_SHA2_256_128/HMAC_SHA2_384_192/HMAC_SHA
2_512_256/HMAC_SHA1_96/AES_XCBC_96/NO_EXT_SEQ
Aug 25 02:34:35 myserver charon: 06[IKE] no acceptable proposal found
Aug 25 02:34:35 myserver charon: 06[IKE] failed to establish CHILD_SA, keeping IKE_SA
Aug 25 02:34:35 myserver charon: 06[IKE] sending DELETE for ESP CHILD_SA with SPI c068db7b
Aug 25 02:34:35 myserver charon: 07[IKE] received DELETE for ESP CHILD_SA with SPI c7a90494
Aug 25 02:34:35 myserver charon: 07[IKE] closing CHILD_SA infonline_datapool{1} with SPIs cbd335d0_i (34701240 bytes) c7a90494_o (451113 bytes) and TS yyy.yyy.yyy.0/25 === 10.10.42.0/24
Aug 25 02:34:35 myserver charon: 07[IKE] sending DELETE for ESP CHILD_SA with SPI cbd335d0
Aug 25 02:34:35 myserver charon: 07[IKE] CHILD_SA closed
Aug 25 02:34:35 myserver charon: 07[IKE] detected CHILD_REKEY collision with CHILD_DELETE
Aug 25 02:34:35 myserver charon: 09[IKE] received DELETE for unknown ESP CHILD_SA with SPI 632d34ba
Aug 25 02:34:35 myserver charon: 09[IKE] CHILD_SA closed
Aug 25 02:34:35 myserver charon: 10[IKE] received DELETE for unknown ESP CHILD_SA with SPI 632d34ba
Aug 25 02:34:35 myserver charon: 10[IKE] CHILD_SA closed
Aug 25 02:34:35 myserver charon: 12[IKE] received DELETE for IKE_SA infonline_datapool[1]
Aug 25 02:34:35 myserver charon: 12[IKE] deleting IKE_SA infonline_datapool[1] between xxx.xxx.xxx.xxx[xxx.xxx.xxx.xxx]...yyy.yyy.yyy.yyy[yyy.yyy.yyy.yyy]
Aug 25 02:34:35 myserver charon: 12[IKE] IKE_SA deleted

我想這裡的關鍵線是：

Aug 25 02:34:25 myserver charon: 12[CFG] received proposals: ESP:AES_CBC_256/HMAC_SHA2_256_128/MODP_2048/NO_EXT_SEQ
Aug 25 02:34:25 myserver charon: 12[CFG] configured proposals: ESP:AES_CBC_256/HMAC_SHA1_96/MODP_2048/NO_EXT_SEQ, ESP:AES_CBC_128/AES_CBC_192/AES_CBC_256/HMAC_SHA2_256_128/HMAC_SHA2_384_192/HMAC_SHA
2_512_256/HMAC_SHA1_96/AES_XCBC_96/NO_EXT_SEQ
Aug 25 02:34:25 myserver charon: 12[IKE] no acceptable proposal found

配置是

conn conn_name
   type=tunnel
   authby=secret
   left=xxx.xxx.xxx.xxx
   leftsubnet=xxx.xxx.xxx.0/25
   right=yyy.yyy.yyy.yyy
   rightsubnet=10.10.42.0/24
   ike=aes256-sha256-modp2048
   ikelifetime=86400s
   esp=aes256-sha1-modp2048
   pfs=yes
   auto=start

如何配置連接以使其不會中斷？（當我重新啟動 ipsec 時，它連接得很好。）

你的分析是準確的，你現在只需要得出正確的結論:)

您可以在您指出的日誌消息中看到對等方提出的算法。由於您配置了 SHA-1 並且對等方提出了 SHA-256，因此沒有匹配項（您配置的預設提議確實包括 SHA-256，但沒有 DH 組，因此也不匹配）。

所以修復很簡單，配置esp=aes256-sha256-modp2048.

引用自：https://serverfault.com/questions/1031366