Hi, I have a network setup where networks 192.168.1.0/24 and 192.168.2.0/24 are served by same router(Cisco 1841, c1841-spservicesk9-mz.124-7a.bin) and while addresses in 192.168.1.0/24 are NAT -ed to inside global address 10.10.10.1, the 192.168.2.0/24 network is not NAT-ed: http://s10.postimg.org/dsn73dzm1/test.png
I would like to deny access from 192.168.2.0/24 network to 192.168.1.0/24. For this reason I have "deny ip 192.168.2.0 0.0.0.255 192.168.1.0 0.0.0.255" ACL in inbound direction on interface facing the 192.168.2.0/24 network: R3#sh ip access-lists 100 Extended IP access list 100 10 deny ip 192.168.2.0 0.0.0.255 192.168.1.0 0.0.0.255 (456 matches) 20 permit ip any any (90 matches) R3# However, at the same time, one should have access from 192.168.1.0/24 network to 192.168.2.0/24 network. Because of the ACL described above, this obviously does not work as returning packages from 192.168.2.0/24 network will have src IP from 192.168.2.0/24 network and dst IP from 192.168.1.0/24 network and will be dropped by ACL. What are the options here? I tried to add second NAT setup which should change the src address of those packets which are from 192.168.1.0/24 AND destined to 192.168.2.0/24. Configuration for this was following: interface Vlan5 description -> T42 eth0 ip address 192.168.1.1 255.255.255.0 ip nat inside end ! interface Vlan10 description -> T60 ip address 192.168.2.1 255.255.255.0 ip access-group 100 in ip nat outside end ! ip nat inside source list 102 interface Vlan10 overload ! access-list 102 permit ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255 ! Such approach seems to work. If I send an ICMP "echo request" package from 192.168.1.2 to 192.168.2.2, then it's NAT -ed and for 192.168.2.2 host this ICMP "echo request" appears to be from 192.168.2.1. In addition, I tried few setups with policy based routing, but eventually none of those worked. What is the best approach here? Stick with this NAT solution described above? Something completely different to separate two networks behind the same router? regards, Martin _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/