이 문서에서는 두 보안 어플라이언스와 인터넷 트래픽을 PAT하여 LAN-to-LAN(L2L) IPsec 터널을 통해 이동하는 VPN 트래픽을 변환(NAT)하는 단계에 대해 설명합니다. 각 보안 어플라이언스에는 그 뒤에 보호되는 사설 네트워크가 있습니다. 이 예에서는 내부 네트워크가 동일하고 겹치는 두 개의 Cisco ASA(Adaptive Security Appliance)가 VPN 터널을 통해 연결됩니다. 일반적인 시나리오에서는 사용자가 동일한 서브넷의 IP 주소를 ping하기 때문에 ping 패킷이 로컬 서브넷에서 나가지 않으므로 VPN 간의 통신이 발생하지 않습니다. 이 두 개인 내부 네트워크가 서로 통신하기 위해 정책 NAT는 로컬 서브넷의 변환을 위해 두 ASA에서 모두 사용되므로 통신이 예상대로 이루어집니다.
이 컨피그레이션 예제를 진행하기 전에 Cisco ASA에 인터페이스의 IP 주소를 구성했는지 확인하고 기본 연결을 설정해야 합니다.
이 문서의 정보는 다음 소프트웨어 버전을 기반으로 합니다.
Cisco Adaptive Security Appliance Software 버전 7.x 이상
이 문서의 정보는 특정 랩 환경의 디바이스를 토대로 작성되었습니다. 이 문서에 사용된 모든 디바이스는 초기화된(기본) 컨피그레이션으로 시작되었습니다. 현재 네트워크가 작동 중인 경우, 모든 명령어의 잠재적인 영향을 미리 숙지하시기 바랍니다.
이 컨피그레이션은 Cisco PIX Security Appliance 버전 7.x 이상에서도 사용할 수 있습니다.
문서 규칙에 대한 자세한 내용은 Cisco 기술 팁 규칙을 참조하십시오.
이 섹션에는 이 문서에서 설명하는 기능을 구성하기 위한 정보가 표시됩니다.
참고: 이 섹션에 사용된 명령에 대한 자세한 내용을 보려면 명령 조회 도구(등록된 고객만 해당)를 사용하십시오.
이 문서에서는 다음 네트워크 설정을 사용합니다.
이 문서에서는 다음 구성을 사용합니다.
ASA-1 |
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ASA-1#show running-config : Saved : ASA Version 8.0(3) ! hostname ciscoasa enable password 8Ry2YjIyt7RRXU24 encrypted names ! interface Ethernet0 nameif outside security-level 0 ip address 172.162.1.1 255.255.255.0 !--- Configure the outside interface. ! interface Ethernet1 nameif inside security-level 100 ip address 192.168.1.1 255.255.255.0 !--- Configure the inside interface. passwd 2KFQnbNIdI.2KYOU encrypted ftp mode passive access-list new extended permit ip 192.168.2.0 255.255.255.0 192.168.3.0 255.255.255.0 !--- This access list (new) is used with the crypto map (outside_map) !--- in order to determine which traffic should be encrypted !--- and sent across the tunnel. access-list policy-nat extended permit ip 192.168.1.0 255.255.255.0 192.168.3.0 255.255.255.0 !--- The policy-nat ACL is used with the static !--- command in order to match the VPN traffic for translation. pager lines 24 mtu outside 1500 mtu inside 1500 no failover asdm image flash:/asdm-615.bin no asdm history enable arp timeout 14400 static (inside,outside) 192.168.2.0 access-list policy-nat !--- It is a Policy NAT statement. !--- The static command with the access list (policy-nat), !--- which matches the VPN traffic and translates the source (192.168.1.0) to !--- 192.168.2.0 for outbound VPN traffic. global (outside) 1 interface nat (inside) 1 0.0.0.0 0.0.0.0 0 0 !--- The previous statements PAT the Internet traffic !--- except for the VPN traffic that uses the IP address 172.17.1.1. route outside 0.0.0.0 0.0.0.0 172.162.1.2 1 !--- Output is suppressed. !--- PHASE 2 CONFIGURATION ---! !--- The encryption types for Phase 2 are defined here. crypto ipsec transform-set CISCO esp-des esp-md5-hmac !--- Define the transform set for Phase 2. crypto map outside_map 20 match address new !--- Define which traffic should be sent to the IPsec peer with the !--- access list (new). crypto map outside_map 20 set peer 172.162.1.2 !--- Sets the IPsec peer (remote end point) crypto map outside_map 20 set transform-set CISCO !--- Sets the IPsec transform set "CISCO" !--- to be used with the crypto map entry "outside_map" crypto map outside_map interface outside !--- Specifies the interface to be used with !--- the settings defined in this configuration !--- PHASE 1 CONFIGURATION ---! !--- This configuration uses isakmp policy 65535. !--- Policy 65535 is included in the configuration by default. !--- These configuration commands define the !--- Phase 1 policy parameters that are used. crypto isakmp identity address crypto isakmp enable outside crypto isakmp policy 65535 authentication pre-share encryption des hash md5 group 2 lifetime 86400 tunnel-group 172.162.1.2 type ipsec-l2l !--- In order to create and manage the database of connection-specific records !--- for IPsec-L2L—IPsec (LAN-to-LAN) tunnels, use the tunnel-group !--- command in global configuration mode. !--- For L2L connections, the name of the tunnel group must be !--- the IP address of the IPsec peer (remote peer end). tunnel-group 172.162.1.2 ipsec-attributes pre-shared-key * !--- Enter the pre-shared key in order to configure the authentication method. telnet timeout 5 ssh timeout 5 console timeout 0 ! class-map inspection_default match default-inspection-traffic ! ! policy-map global_policy class inspection_default inspect dns maximum-length 512 inspect ftp inspect h323 h225 inspect h323 ras inspect netbios inspect rsh inspect rtsp inspect skinny inspect esmtp inspect sqlnet inspect sunrpc inspect tftp inspect sip inspect xdmcp ! service-policy global_policy global Cryptochecksum:33e1e37cd1280d908210dac0cc26e706 : end |
ASA-2 |
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ASA-2#show running-config : Saved : ASA Version 8.0(3) ! hostname ASA-2 enable password 8Ry2YjIyt7RRXU24 encrypted names ! interface Ethernet0 nameif outside security-level 0 ip address 172.162.1.2 255.255.255.0 ! interface Ethernet1 nameif inside security-level 100 ip address 192.168.1.1 255.255.255.0 ! !--- Output is suppressed. access-list new extended permit ip 192.168.3.0 255.255.255.0 192.168.2.0 255.255.255.0 !--- This access list (new) is used with the crypto map (outside_map) !--- in order to determine which traffic needs to be encrypted !--- and sent across the tunnel. access-list policy-nat extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0 !--- The policy-nat ACL is used with the static !--- command in order to match the VPN traffic for translation. pager lines 24 mtu outside 1500 mtu inside 1500 no failover asdm image flash:/asdm-615.bin no asdm history enable arp timeout 14400 static (inside,outside) 192.168.3.0 access-list policy-nat !--- This is a Policy NAT statement. !--- The static command with the access list (policy-nat), !--- which matches the VPN traffic and translates the source (192.168.1.0) to !--- 192.168.3.0 for outbound VPN traffic. global (outside) 1 interface nat (inside) 1 0.0.0.0 0.0.0.0 0 0 !--- The previous statements PAT the Internet traffic !--- except the VPN traffic that uses the outside interface IP address. route outside 0.0.0.0 0.0.0.0 172.162.1.2 1 !--- PHASE 2 CONFIGURATION ---! !--- The encryption types for Phase 2 are defined here. crypto ipsec transform-set CISCO esp-des esp-md5-hmac !--- Define the transform set for Phase 2. crypto map outside_map 20 match address new !--- Define which traffic needs to be sent to the IPsec peer. crypto map outside_map 20 set peer 172.162.1.1 !--- Sets the IPsec peer. crypto map outside_map 20 set transform-set CISCO !--- Sets the IPsec transform set "CISCO" !--- to be used with the crypto map entry "outside_map". crypto map outside_map interface outside !--- Specifies the interface to be used with !--- the settings defined in this configuration. !--- PHASE 1 CONFIGURATION ---! !--- This configuration uses isakmp policy 65535 !--- which is included in the configuration by default. !--- The configuration commands here define the !--- Phase 1 policy parameters that are used. crypto isakmp identity address crypto isakmp enable outside crypto isakmp policy 65535 authentication pre-share encryption des hash md5 group 2 lifetime 86400 !--- Output is suppressed. !--- In order to create and manage the database of connection-specific !--- records for IPsec-L2L—IPsec (LAN-to-LAN) tunnels, use the !--- tunnel-group command in global configuration mode. !--- For L2L connections, the name of the tunnel group must be !--- the IP address of the IPsec peer. tunnel-group 172.162.1.1 type ipsec-l2l tunnel-group 172.162.1.1 ipsec-attributes pre-shared-key * !--- Enter the pre-shared key in order to configure the authentication method. prompt hostname context Cryptochecksum:6b505b4a05c1aee96a71e67c23e71865 : end |
이 섹션을 사용하여 컨피그레이션이 제대로 작동하는지 확인합니다.
Output Interpreter 도구(등록된 고객만 해당)(OIT)는 특정 show 명령을 지원합니다. show 명령 출력의 분석을 보려면 OIT를 사용합니다.
show crypto isakmp sa - 피어의 현재 IKE SA(Security Associations)를 모두 표시합니다.
show crypto ipsec sa - 현재 SA에서 사용하는 설정을 표시합니다.
ASA-1#show crypto isakmp sa 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: 172.162.1.2 Type : L2L Role : initiator Rekey : no State : MM_ACTIVE
ASA-1#show crypto ipsec sa interface: outside Crypto map tag: outside_map, seq num: 20, local addr: 172.162.1.1 access-list new permit ip 192.168.2.0 255.255.255.0 192.168.3.0 255.255.2 5.0 local ident (addr/mask/prot/port): (192.168.2.0/255.255.255.0/0/0) remote ident (addr/mask/prot/port): (192.168.3.0/255.255.255.0/0/0) current_peer: 172.162.1.2 #pkts encaps: 9, #pkts encrypt: 9, #pkts digest: 9 #pkts decaps: 9, #pkts decrypt: 9, #pkts verify: 9 #pkts compressed: 0, #pkts decompressed: 0 #pkts not compressed: 9, #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.: 172.162.1.1, remote crypto endpt.: 172.162.1.2 path mtu 1500, ipsec overhead 58, media mtu 1500 current outbound spi: 0BA6CD7E inbound esp sas: spi: 0xFB4BD01A (4216049690) transform: esp-des esp-md5-hmac none in use settings ={L2L, Tunnel, } slot: 0, conn_id: 8192, crypto-map: outside_map sa timing: remaining key lifetime (kB/sec): (3824999/27738) IV size: 8 bytes replay detection support: Y outbound esp sas: spi: 0x0BA6CD7E (195480958) transform: esp-des esp-md5-hmac none in use settings ={L2L, Tunnel, } slot: 0, conn_id: 8192, crypto-map: outside_map sa timing: remaining key lifetime (kB/sec): (3824999/27738) IV size: 8 bytes replay detection support: Y
ASA-1#show nat NAT policies on Interface inside: match ip inside 192.168.1.0 255.255.255.0 outside 192.168.3.0 255.255.255.0 static translation to 192.168.2.0 translate_hits = 12, untranslate_hits = 5 match ip inside any outside any dynamic translation to pool 1 (172.162.1.1 [Interface PAT]) translate_hits = 0, untranslate_hits = 0 match ip inside any inside any dynamic translation to pool 1 (No matching global) translate_hits = 0, untranslate_hits = 0 match ip inside any dmz any dynamic translation to pool 1 (No matching global) translate_hits = 0, untranslate_hits = 0
ASA-1#show xlate 1 in use, 1 most used Global 192.168.2.0 Local 192.168.1.0
ASA-2#show crypto ipsec sa interface: outside Crypto map tag: outside_map, seq num: 20, local addr: 172.162.1.2 access-list new permit ip 192.168.3.0 255.255.255.0 192.168.2.0 255.255.25 5.0 local ident (addr/mask/prot/port): (192.168.3.0/255.255.255.0/0/0) remote ident (addr/mask/prot/port): (192.168.2.0/255.255.255.0/0/0) current_peer: 172.162.1.1 #pkts encaps: 9, #pkts encrypt: 9, #pkts digest: 9 #pkts decaps: 9, #pkts decrypt: 9, #pkts verify: 9 #pkts compressed: 0, #pkts decompressed: 0 #pkts not compressed: 9, #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.: 172.162.1.2, remote crypto endpt.: 172.162.1.1 path mtu 1500, ipsec overhead 58, media mtu 1500 current outbound spi: FB4BD01A inbound esp sas: spi: 0x0BA6CD7E (195480958) transform: esp-des esp-md5-hmac none in use settings ={L2L, Tunnel, } slot: 0, conn_id: 8192, crypto-map: outside_map sa timing: remaining key lifetime (kB/sec): (4274999/26902) IV size: 8 bytes replay detection support: Y outbound esp sas: spi: 0xFB4BD01A (4216049690) transform: esp-des esp-md5-hmac none in use settings ={L2L, Tunnel, } slot: 0, conn_id: 8192, crypto-map: outside_map sa timing: remaining key lifetime (kB/sec): (4274999/26902) IV size: 8 bytes replay detection support: Y
ASA-2#show crypto isakmp sa 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: 172.162.1.1 Type : L2L Role : responder Rekey : no State : MM_ACTIVE
문제를 해결할 때 변경 후 기존 SA를 지워야 합니다. PIX의 특권 모드에서 다음 명령을 사용합니다.
clear crypto ipsec sa - 활성 IPsec SA를 삭제합니다.
clear crypto isakmp sa - 활성 IKE SA를 삭제합니다.
Output Interpreter 도구(등록된 고객만 해당)는 특정 show 명령을 지원합니다. show 명령 출력의 분석을 보려면 OIT를 사용합니다.
참고: debug 명령을 사용하기 전에 디버그 명령에 대한 중요 정보를 참조하십시오.
debug crypto ipsec - 2단계의 IPsec 협상을 표시합니다.
debug crypto isakmp - 1단계의 ISAKMP 협상을 표시합니다.
개정 | 게시 날짜 | 의견 |
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1.0 |
09-Dec-2010 |
최초 릴리스 |