No internet with static public ip address 1

[octavian10]

Can someone please answer a simple question about a 2621 router that I am playing with? I have the follwoing configuration working no problem for letting internal users access the internet.

interface FastEthernet0/0
ip address dhcp
ip nat outside
duplex auto
speed auto

interface FastEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
duplex auto
speed auto

ip nat inside source list 100 interface fastethernet0/0 overload

access-list 100 permit ip 192.168.1.1 0.0.0.255 any

The problem I have is that if I take the public address issued to the router and staticly assign it to Fastethernet0/0 the internet access no longer works. Example
interface Fastethernet0/0
ip address 24.50.xx.xx 255.255.255.0
ip nat outside
duplex auto
speed auto
24.50.xx.xx 255.255.255.0 was issued to the router by the isp when fastethernet0/0 was in ip address dhcp mode.



"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)

 

[JOAMON]

Can you post the rest of the config....sounds like a default route problem....when you change so static ip you should also change default route to the ip address of the next hop router.

 

[JOAMON]

What type of internet connection do you have and is there another modem or router involved with your connection?

 

[octavian10]

Her you go thanks for your time.
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
!
ip subnet zero
!
ip audit notify log
ip audit po max-events 100
!
no voice hpi capture buffer
no voice hpi capture destination
!
interface FastEthernet0/0
ip address 24.50.xx.xx 255.255.255.0
ip nat outside
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
duplex auto
speed auto
!
ip nat inside source list 100 interface FastEthernet0/0 overload
ip http server
no ip http secure-server
ip classless
!
access-list 100 permit ip 192.168.1.1 0.0.0.255 any
!
line con 0
line aux 0
line vtu 0 4
!
end

Thats all of it


"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)

 

[octavian10]

I have a cable modem connected directly to FastEthernet0/0

"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)

 

[JOAMON]

Is the internet service you signed up for a static service? Typically cable internet is dynamic. If you are trying to assign a static address to a dynamic service it will not work.

Aside from that the above configuration must have a default route:

ip route 0.0.0.0 0.0.0.0 XXX.XXX.XXX.XXX (next hop router after router interface f0/0) Because this is an ethernet interface do not just use ip route 0.0.0.0 0.0.0.0 fastethernet0/0 as your arp cache will be huge.

 

[octavian10]

The internet service right now is dynamic, I have not yet requested a static ip address from my isp but plan to do so in the near future, hence the testing I am trying to do by grabbing the issued dhcp address and making it static. So you are saying that when I request this static address I should also request the ip address and mask of the next hop router? Also why wont this dhcp issued address work in a static role? Thanks again

"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)

 

[JOAMON]

When your interface gets its address automatically it knows the next hop to get to the internet. When the address is assigned statically you must then tell it were to go ie....next hop. When you signup for static this will be provided to you. Could be that if you do not authenticate on the cable network through thier DHCP server that you are denied access. Also a DHCP server has a pool of address and if you assgin one of those static the DHCP server will be unaware of it and possibly assign it to another machine which will make both unusable. If you still want to test then you must find the next hop router and put it as the default route as mentioned previously.

 

[octavian10]

Thanks again for your time. I just requested the static address and they gave me the address for the next hop. They also gave me DNS server address, do I need to input thes into my router also?

"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)

 

[octavian10]

Additionally, if I am not to use 0.0.0.0 0.0.0.0 as the ip route, what should I use?

"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)

 

[JOAMON]

you dont want to use
ip route 0.0.0.0 0.0.0.0 fastethernet0/0

you want to use
ip route 0.0.0.0 0.0.0.0 XXX.XXX.XXX.XXX (X=next hop ip address)

Your PC's must have a valid DNS entry to be able to go anywhere on the net. They either are assigned this via DHCP or Static. Once you get router on the net then go to a PC and see if you can ping

http://www.google.com

If it converts it to a numeric IP address then the PC should be ok.

 

[octavian10]

Thanks for all your info you made this transition to a static address much less complicated then I thought it would be.

"I hear and I forget. I see and I remember. I do and I understand."
- Confucius (551 BC - 479)