08-29-2008 07:38 AM - edited 03-06-2019 01:04 AM
Hello all,
I just got Comcast internet with dynamic ip. I am installing cisco 1811 behind the comcast modem. But I cannot send the traffic out. I tried with and w/o BVI option in 1811 but still does not work. Does anyone have any suggestion?
Here are some basical config:
int fas 0
ip add dhcp
ip nat outside
int vlan 1
ip add 192.168.0.1 255.255.255.0
ip nat inside
ip nat inside source route-map NoNat interface fas 0 overload
ip access-list extended NATList
deny ip 192.168.0.0 0.0.0.255 10.0.0.0 0.255.255.255
deny ip 192.168.0.0 0.0.0.255 172.16.0.0 0.15.255.255
deny ip 192.168.0.0 0.0.0.255 192.168.0.0 0.0.255.255
permit ip 192.168.0.0 0.0.0.255 any
!
!
route-map nonat permit 10
match ip address NATList
ip route 0.0.0.0 0.0.0.0 FastEthernet0 name DefaultRouteToComcast
I called Comcast; they said the modem only allows one config and they don't know how to config anything behind the modem other than PCs.
Any help will be greatly apprecated!
thanks,
Gene
08-29-2008 08:09 AM
first off. Is the FAS interface getting a DHCP Address from comcast?
08-29-2008 08:49 AM
When you plug your PC into the modem, does it get a public or private IP address?
08-29-2008 09:12 AM
Public Address.
If I use router's fe 0 dhcp, I am getting completed different class of public ip than PC gets.
thanks,
08-29-2008 09:27 AM
Once you plug in the router and get an IP, can you ping the default gateway?
08-29-2008 09:56 AM
Don't know the default gateway if I use router. The ip I am getting is like 24.x.x.x different than the IP I am getting from PC 74.x.x.x. If I hard code the 74.x.x.x and default gateway into router fe interface and setup the default route, then I can ping.
thanks,
08-29-2008 01:04 PM
OK, let's move forward and address that later. Can the router ping an internet address like 4.2.2.2? If yes, can the router ping it when you source from the LAN side?
08-29-2008 01:18 PM
No, cannot even ping anything outside before the extended ping.
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