Re: [TCLUG:19111] Cisco 675 and my network...

[Jon Schewe <jpschewe@eggplant.mtu.net>]

Should be setup just like my network, I've got two ethernet cards in my
firewall box, the external one gets EXT-IP, the other gets INT-IP.  So
here's the setup I've got.  INT-IP is in the 192.168.42.* range.  ROUTER is
my router, when then knows to talk to the ISP's gateway.

>netstat -rn
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
INT-IP          0.0.0.0         255.255.255.255 UH        0 0          0 eth0
EXT-IP          0.0.0.0         255.255.255.255 UH        0 0          0 eth1
127.0.0.1       0.0.0.0         255.255.255.255 UH        0 0          0 lo
192.168.42.0    0.0.0.0         255.255.255.0   U         0 0          0 eth0
0.0.0.0         ROUTER          0.0.0.0         UG        0 0          0 eth1
jpschewe@disk:~
>ifconfig
eth0      Link encap:Ethernet  HWaddr 00:80:48:C6:1F:A2  
          inet addr:INT-IP  Bcast:192.168.42.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4248130 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5606251 errors:4 dropped:0 overruns:0 carrier:4
          collisions:3489 txqueuelen:100 
          Interrupt:10 Base address:0xef80 

eth1      Link encap:Ethernet  HWaddr 00:C0:6D:15:9A:8F  
          inet addr:EXT-IP  Bcast:137.192.255.255  Mask:255.255.255.252
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3996917 errors:0 dropped:0 overruns:0 frame:15
          TX packets:2851098 errors:1 dropped:0 overruns:1 carrier:0
          collisions:257 txqueuelen:100 
          Interrupt:9 Base address:0xef40 

I think one thing that really helps here is the my external IP is in a
completly different range from my set of internal addresses so it's real easy
to separate them.

-- 
Jon Schewe 
http://eggplant.mtu.net/~jpschewe
schewe@tcfreenet.org