Hi,I'm trying to setup a firewall at our data center and I think I'm missing a few things here. I have a Class C ip range, lets call it 1.2.3.0/24. I have a firewall running kernel 2.6.9 and iptables 1.2.11. My firewall has 2 network interfaces, on the external interface I've added an alias for each external ip that I want to nat to internal servers:
eg. ifconfig eth0:0 1.2.3.10 netmask 255.255.255.0 (Is this the correct way to use multiple ip's?) My servers on the inside interface are on the 192.168.0.0/24 network. I'm able to ssh to an internal server via an external ip address.The problem is I can't seem to connect out (via ssh, dns, www etc) from the inside servers. There is a rule blocking these connections as it shows me in the firewall logs:
Oct 25 18:27:22 fw1 kernel: IN=eth1 OUT=eth0 SRC=192.168.0.20 DST=4.3.2.1 LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=28642 DF PROTO=UDP SPT=32769 DPT=53 LEN=40 Oct 25 18:27:31 fw1 kernel: IN=eth1 OUT=eth0 SRC=192.168.0.20 DST=4.3.2.1 LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=18271 DF PROTO=TCP SPT=32792 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0
I've attached my firewall script, could someone please take a look at it and give me a hand. Or if they have a similar setup, could you send me your config. If there is a better way to do this, please let me know.
Many thanks, Marc
Attachment:
firewall.sh
Description: application/shellscript
