Context-Based Access Control (CBAC) 基于上下文的访问控制 实验

【实验说明】

配置路由器出站流量检查，动态打开ACL条目

 

IOS：c7200-adventerprisek9-mz.124-24.T3.bin

 

【实验拓扑】

 

【实验配置向导】

• 将上面网络配置为 IP service 实验中的“Standard NAT with Overloading(PAT)”
• 创建检查规则命名为 INSPECT，允许TCP协议
• 创建检查规则命名为 INSPECT ，允许FTP流量通过路由器
• 配置规则允许ICMP 并检查路由器自身产生的TCP与ICMP流量
• 创建 INBOUND 访问控制列表，允许OSPF，并阻止其他流量
• 在路由器的串口的入方向应用访问控制列表 INBOUND
• 应用检查规则到路由器串口的出方向

 

【实验配置】

--------------------------------实验PAT配置---------------------------------------------------------

R1: interface FastEthernet0/0 ip address 10.0.0.1 255.255.255.0 no sh ip route 0.0.0.0 0.0.0.0 10.0.0.4   R6: interface FastEthernet0/0 ip address 10.0.0.6 255.255.255.0 no sh ip route 0.0.0.0 0.0.0.0 10.0.0.4   R4： interface Loopback0 ip address 150.1.4.4 255.255.255.0 ip ospf network point-to-point no sh ! interface FastEthernet0/0 ip address 10.0.0.4 255.255.255.0 ip nat inside no sh ! interface serial1/0 en fram no sh ! interface Serial1/0.1 point-to-point ip address 155.1.0.4 255.255.255.0 frame-relay interface-dlci 405 ip nat outside no sh ! interface Serial1/1 ip address 155.1.45.4 255.255.255.0 clock rate 2000000 ip nat outside no sh ! router ospf 1 router-id 150.1.4.4 network 150.1.4.4 0.0.0.0 area 0 network 155.1.0.4 0.0.0.0 area 0 network 155.1.45.4 0.0.0.0 area 0 ! router bgp 1 bgp router-id 150.1.4.4 neighbor 150.1.5.5 remote-as 2 neighbor 150.1.5.5 ebgp-multihop 255 neighbor 150.1.5.5 update-source Loopback0 ! ip access-list standard INSIDE_NETWORK permit 10.0.0.0 0.0.0.255 ! ip nat inside source list INSIDE_NETWORK interface Loop0 overload

R5: interface Loopback0 ip address 150.1.5.5 255.255.255.0 ip ospf network point-to-point no sh ! interface Serial1/0 encapsulation frame-relay no sh ! interface Serial1/0.1 point-to-point ip address 155.1.0.5 255.255.255.0 frame-relay interface-dlci 504 no sh ! interface Serial1/1 ip address 155.1.45.5 255.255.255.0 clock rate 2000000 no sh ! router ospf 1 router-id 150.1.5.5 network 150.1.5.5 0.0.0.0 area 0 network 155.1.0.5 0.0.0.0 area 0 network 155.1.45.5 0.0.0.0 area 0 ! router bgp 2 bgp router-id 150.1.5.5 neighbor 150.1.4.4 remote-as 1 neighbor 150.1.4.4 ebgp-multihop 255 neighbor 150.1.4.4 update-source Loopback0 neighbor 150.1.4.4 default-originate

--------- ---------------------------------------CBAC 配置----------------------------------------------------------

【实验配置】

R4:

ip inspect name INSPECT ftp

ip inspect name INSPECT icmp router-traffic

ip inspect name INSPECT tcp router-traffic

!

ip access-list ext INBOUND

permit ospf any any

deny ip any any log

!

interface Serial 0/1

ip access-group INBOUND in

ip inspect INSPECT out

!

interface Serial 0/0.1

ip access-group INBOUND in

ip inspect INSPECT out

 

【实验验证】

R4#show ip inspect config

Session audit trail is disabled

Session alert is enabled

one-minute (sampling period) thresholds are [400:500] connections

max-incomplete sessions thresholds are [400:500]

max-incomplete tcp connections per host is 50. Block-time 0 minute.

tcp synwait-time is 30 sec -- tcp finwait-time is 5 sec

tcp idle-time is 3600 sec -- udp idle-time is 30 sec

dns-timeout is 5 sec

Inspection Rule Configuration

Inspection name INSPECT

http alert is on audit-trail is off timeout 3600

ftp alert is on audit-trail is off timeout 3600

icmp alert is on audit-trail is off timeout 10

telnet alert is on audit-trail is off timeout 3600

router alert is on audit-trail is off timeout 30

R6#telnet 150.1.5.5

Trying 150.1.5.5 ... Open

R5>

R4#show ip inspect sessions

Established Sessions

Session 650FF88C (10.0.0.6:54327)=>(150.1.5.5:23) tcp SIS_OPEN

Session 650FFB04 (150.1.4.4:40087)=>(150.1.5.5:179) tcp SIS_OPEN

R4#ping 150.1.5.5

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 150.1.5.5, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 44/44/48 ms

R4#telnet 150.1.5.5

Trying 150.1.5.5 ... Open