Transparent Cisco IOS Firewall

Lessons Discussion
8

I just labbed this up again, just in case I’m not losing my mind :grin:

On Cisco VIRL, it’s also not working for me. I can ping between R3 and R1 without issues and I don’t get any hits on my access-lists.

On my older 2800 routers running IOS 15.1(4)M10 it’s working though:

R1#show version 
Cisco IOS Software, 2800 Software (C2800NM-ADVENTERPRISEK9-M), Version 15.1(4)M10, RELEASE SOFTWARE (fc2)

Let’s enable a debug on R2:

R2#debug ip packet
IP packet debugging is on

Try a ping from R3:

R3#ping 192.168.13.1 repeat 1000 timeout 0

R2 drops them:

R2#show access-lists R3-TO-R1
Extended IP access list R3-TO-R1
    10 deny ip any any (1027 matches)

Ping from R1:

R1#ping 192.168.13.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.13.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

This is traffic that R2 inspects:

R2#show ip inspect sessions 
Established Sessions
 Session 49BFA068 (192.168.13.1:8)=>(192.168.13.3:0) icmp SIS_OPEN

Rene