topic Re: PIX: does it route packets on the inside interfece in Network Security

PIX: does it route packets on the inside interfece

ifinet — Fri, 21 Feb 2020 06:37:28 GMT

I have a PIX with 2 interfaces: "inside" and "outside". I have no problem when a packet coming from a "inside net" PC (C) has to go outside. But if I have to reach an other network that is "inside" (192.168.0.0), it doesn't work; let's see the scheme below:

---192.168.0.0/24---

B C

| |

---172.31.0.0/16 (inside)---

PIX

----(outside)---

R----> Internet

---------------------------------------

I need to reach A from C (PIX is the default gateway of C and it has a specific route to A passing through B)

The question is: does the PIX route packets coming from inside to an other gateway that is on the same (inside) interface?

Re: PIX: does it route packets on the inside interfece

0rsnaric — Fri, 14 Mar 2003 17:45:07 GMT

No. The pix will not forward packets back out the interface it recieved them on. So even if you put a static route on the pix pointing back to the subnet A, the pix will drop the packets.

~rls

Re: PIX: does it route packets on the inside interfece

shannong — Fri, 14 Mar 2003 18:57:37 GMT

Assuming you have a router at B to get to A, you need make make that router B the default gateway of the C subnet.

Re: PIX: does it route packets on the inside interfece

brent.smith — Fri, 14 Mar 2003 22:44:41 GMT

The problem with making B your defualt-gateway is those nodes will start getting "icmp redirect". You should redisign your network so that the network that connects router b to PIX is a 30 bit. Like the first reply said, PIX is not ment to route inside traffic.