安全防御 --- IPSec理论（02）
附：
协议与模式分类
esp 和 ah 的分类：
- 数据的安全性：ESP有机密性；AH无机密性
- 场景：ESP适合公网场景；AH适合内网 / 私网场景
（数据的安全性主要依赖于传输端之间需要做认证）
传输模式和隧道模式的分类：
- 传输端的可达性：传输模式有可达性；隧道模式无可达性
- 场景：传输模式（私网数据通过公网传输；异种网络之间通过其他网络传输）；隧道模式（专线，隧道已做，本身路由可达）
ipsec配置（路由器）
静态路由协议下的IPSec
保证基础网络可达
[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ip add 100.1.1.1 24
[r1]ip route-static 0.0.0.0 0 100.1.1.2
[ISP]int g0/0/0
[ISP-GigabitEthernet0/0/0]ip add 100.1.1.2 24
[ISP]int g0/0/1
[ISP-GigabitEthernet0/0/1]ip ad 100.1.2.1 24
[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ip add 100.1.2.2 24
[r2]ip route-static 0.0.0.0 0 100.1.2.1
[r1]int LoopBack 0
[r1-LoopBack0]ip add 172.16.10.1 24
[r2]int LoopBack 0
[r2-LoopBack0]ip add 172.16.1.1 24
（1）配置 IKE SA
<1> 安全提议
[r1]ike proposal 1 // 安全提议编号
[r1-ike-proposal-1]encryption-algorithm 3des-cbc // 加密算法（3des）
[r1-ike-proposal-1]authentication-algorithm sha1 // 认证算法（sha1）
[r1-ike-proposal-1]authentication-method pre-share // 认证模式（预共享：pre）
[r1-ike-proposal-1]dh group2 // 非对称加密算法强度
[r1]dis ike proposal --- 查看未显示以及默认配置
Number of IKE Proposals: 2
-------------------------------------------
IKE Proposal: 1
Authentication method : pre-shared
Authentication algorithm : SHA1
Encryption algorithm : 3DES-CBC
DH group : MODP-1024
SA duration : 3600
PRF : PRF-HMAC-SHA
-------------------------------------------
-------------------------------------------
IKE Proposal: Default
Authentication method : pre-shared
Authentication algorithm : SHA1
Encryption algorithm : DES-CBC
DH group : MODP-768
SA duration : 86400
PRF : PRF-HMAC-SHA
-------------------------------------------
[r2]ike proposal 1
[r2-ike-proposal-1]encryption-algorithm 3des-cbc
[r2-ike-proposal-1]dh group2
[r2-ike-proposal-1]sa duration 3600PRF：完美向前法。
<2> 安全认证
[r1]ike peer 12 v1 // ike认证名称和版本
[r1-ike-peer-12]exchange-mode main // 模式选择（默认主模式）
[r1-ike-peer-12]pre-shared-key cipher 234 // 编译预共享密钥
[r1-ike-peer-12]ike-proposal 1 // 调用安全提议
[r1-ike-peer-12]remote-address 100.1.2.2 // 调用远端地址
[r2]ike peer 12 v1
[r2-ike-peer-12]ike-proposal 1
[r2-ike-peer-12]pre-shared-key cipher 234
[r2-ike-peer-12]remote-address 100.1.1.1
[r2-ike-peer-12]exchange-mode main（2）配置IPSec SA 安全提议信息
[r1]ipsec proposal 1 // ipsec提议
[r1-ipsec-proposal-1]transform esp // 选择传输协议
[r1-ipsec-proposal-1]esp authentication-algorithm sha2-512 // 认证算法
[r1-ipsec-proposal-1]esp encryption-algorithm aes-128 // 加密算法
[r1-ipsec-proposal-1]encapsulation-mode tunnel // 封装模式（隧道模式）
[r1]dis ipsec proposal --- 查看
Number of proposals: 1
IPSec proposal name: 1
Encapsulation mode: Tunnel
Transform : esp-new
ESP protocol : Authentication SHA2-HMAC-512
Encryption AES-128
[r2]ipsec proposal 1
[r2-ipsec-proposal-1]transform esp
[r2-ipsec-proposal-1]encapsulation-mode tunnel
[r2-ipsec-proposal-1]esp authentication-algorithm sha2-512
[r2-ipsec-proposal-1]esp encryption-algorithm aes-128（3）定义加密流量（感兴趣流）
[r1]acl 3000
[r1-acl-adv-3000]rule 5 permit ip source 172.16.10.1 0.0.0.0 destination 172.16.1.1 0.0.0.0
[r2]acl 3000
[r2-acl-adv-3000]rule 5 permit ip source 172.16.1.1 0.0.0.0 destination 172.16.10.1 0.0.0.0（4）配置安全策略集
[r1]ipsec policy k 10 isakmp --- 定义名为k，序列号为10，运用isakmp（IKE）进行协商
[r1-ipsec-policy-isakmp-k-10]ike-peer 12 // 关联ike-peer
[r1-ipsec-policy-isakmp-k-10]security acl 3000 // 关联感兴趣流
[r1-ipsec-policy-isakmp-k-10]pfs dh-group2 // pfs：完美向前法
[r2]ipsec policy k 10 isakmp
[r2-ipsec-policy-isakmp-k-10]ike-peer 12
[r2-ipsec-policy-isakmp-k-10]proposal 1
[r2-ipsec-policy-isakmp-k-10]security acl 3000
[r2-ipsec-policy-isakmp-k-10]pfs dh-group2（5）接口调用安全策略集
[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ipsec policy k
[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ipsec policy k进行触发：
（6）查看安全联盟建立情况
dis ike sa
Conn-ID Peer VPN Flag(s) Phase
---------------------------------------------------------------
2 100.1.2.2 0 RD|ST 2
1 100.1.2.2 0 RD|ST 1
Flag Description:
RD--READY ST--STAYALIVE RL--REPLACED FD--FADING TO--TIMEOUT
HRT--HEARTBEAT LKG--LAST KNOWN GOOD SEQ NO. BCK--BACKED UP
dis ipsec sa
[Outbound ESP SAs]
SPI: 1407390962 (0x53e314f2)
Proposal: ESP-ENCRYPT-AES-128 SHA2-512-256
SA remaining key duration (bytes/sec): 1887329280/2740
Max sent sequence-number: 5
UDP encapsulation used for NAT traversal: N
[Inbound ESP SAs]
SPI: 3197321182 (0xbe933fde)
Proposal: ESP-ENCRYPT-AES-128 SHA2-512-256
SA remaining key duration (bytes/sec): 1887436380/2740
Max received sequence-number: 5
Anti-replay window size: 32
UDP encapsulation used for NAT traversal: N
动态路由协议下的IPSec
新建环回
[r1]int LoopBack 0
[r1-LoopBack1]ip ad 1.1.1.1 24
gre下的隧道配置
[r1]int t0/0/0
[r1-Tunnel0/0/0]tunnel-protocol gre
[r1-Tunnel0/0/0]source g0/0/0
[r1-Tunnel0/0/0]destination 100.1.2.2
[r1-Tunnel0/0/0]ip add 10.1.1.1 24
[r2]int lo 1
[r2-LoopBack1]ip add 2.2.2.2 24
[r2]int t0/0/0
[r2-Tunnel0/0/0]tunnel-protocol gre
[r2-Tunnel0/0/0]source g0/0/0
[r2-Tunnel0/0/0]destination 100.1.1.1
[r2-Tunnel0/0/0]ip add 10.1.1.2 24
ospf配置
[r1]ospf 1
[r1-ospf-1]a 0
[r1-ospf-1-area-0.0.0.0]network 1.1.1.1 0.0.0.0
[r1-ospf-1-area-0.0.0.0]network 10.1.1.1 0.0.0.0
[r2]ospf 1
[r2-ospf-1]a 0
[r2-ospf-1-area-0.0.0.0]network 2.2.2.2 0.0.0.0
[r2-ospf-1-area-0.0.0.0]network 10.1.1.2 0.0.0.0
查看邻居建立情况
[r1]dis ospf peer brief
OSPF Process 1 with Router ID 100.1.1.1
Peer Statistic Information
----------------------------------------------------------------------------
Area Id Interface Neighbor id State
0.0.0.0 Tunnel0/0/0 100.1.2.2 Full
----------------------------------------------------------------------------（1）配置 IKE SA
<1> 安全提议
[r1]ike proposal 10
[r1-ike-proposal-10]encryption-algorithm 3des-cbc
[r1-ike-proposal-10]authentication-algorithm sha1
[r1-ike-proposal-10]authentication-method pre-share
[r1-ike-proposal-10]dh group2
[r2]ike proposal 10
[r2-ike-proposal-10]encryption-algorithm 3des-cbc
[r2-ike-proposal-10]authentication-algorithm sha1
[r2-ike-proposal-10]authentication-method pre-share
[r2-ike-proposal-10]dh group2<2> 安全认证
[r1]ike peer gre v1
[r1-ike-peer-gre]pre-shared-key simple aaa // 设置预共享密钥（simple：本地不加密）
[r1-ike-peer-gre]exchange-mode aggressive // 采用野蛮模式
[r1-ike-peer-gre]local-id-type name // 采用name定义
[r1-ike-peer-gre]remote-name a1 // 远端name为a1
[r1-ike-peer-gre]remote-address 100.1.2.2 // 远端IP
[r1-ike-peer-gre]ike-proposal 10 // 引用ike
[r1]ike local-name a1 // 全局定义本地name
[r2]ike peer gre v1
[r2-ike-peer-gre]ike-proposal 10
[r2-ike-peer-gre]pre-shared-key simple aaa
[r2-ike-peer-gre]remote-address 100.1.1.1
[r2-ike-peer-gre]exchange-mode aggressive
[r2-ike-peer-gre]local-id-type name
[r2-ike-peer-gre]remote-name a1（2）配置ipsec sa 的安全提议信息
[r1]ipsec proposal gre
[r1-ipsec-proposal-gre]encapsulation-mode transport
[r2]ipsec proposal gre
[r2-ipsec-proposal-gre]encapsulation-mode transport
（3）定义加密流量（感兴趣流）
[r1]acl 3001
[r1-acl-adv-3001]rule 10 permit gre source 100.1.1.1 0 destination 100.1.2.2 0
[r2]acl 3001
[r2-acl-adv-3001]rule 10 permit gre source 100.1.2.2 0 destination 100.1.1.1 0
（4）配置安全策略集
[r1]ipsec policy gre 10 isakmp
[r1-ipsec-policy-isakmp-gre-10]ike-peer gre
[r1-ipsec-policy-isakmp-gre-10]proposal gre
[r1-ipsec-policy-isakmp-gre-10]security acl 3001
[r2]ipsec policy gre 10 isakmp
[r2-ipsec-policy-isakmp-gre-10]security acl 3001
[r2-ipsec-policy-isakmp-gre-10]proposal gre
[r2-ipsec-policy-isakmp-gre-10]ike-peer gre（5）接口调用安全策略集
[r1]int g0/0/0
[r1-GigabitEthernet0/0/0]ipsec policy gre
[r2]int g0/0/0
[r2-GigabitEthernet0/0/0]ipsec policy greping进行触发：
流量已加密
（6）分析
