Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

dhcp address?

hello all,

i have just managed to get my hands on a second hand 2500 series router and i would like to configure it for use in my house.

so far i have got up to wiping the old config off the router, so i have a blank canvas to play with.

here is my setup:

isp conntection ------> 2500 router --> my internal network

my isp has geven me a router to access the internet with but have told me not to edit the configuration on it.

my isp gives me my ip address via dhcp so i need to configure one of the ethernet ports on my 2500 router to reconfigure its self according to what their dhcp server gives me.

i have worked out how to configure the other ethernet port to work on my internal network and i can ping the router from inside my network, so that seems to work correctly.

when i configure the other port, will the router automaticaly work out that i want to pass information from one network to the other, or will i have to tell it what i want to do?

i would be very happy if some one can help

thanking you inadvance

steve keners

Cisco Employee

Re: dhcp address?

Try to understand the setup here..three questins?

1)how 2500 router connected with physically ISP..Via T1/BRI/serial port or other way?

2)Which port of 2500 will get the ip address assigned from the dhcp of ISP?

3)how many eth port you have on 2500?

That will help to answer the questions.

Now in general, the 2500 connects to isp via dialup/leased line so ip will assign ip address "dynamically" (from their dhcp) to that port on 2500.

You can run "NAT" from inside privet network to outside isp network to access it. For that you ned to inform the router what to do. So lets know more in regards to those three q's.Thx..Tejal

New Member

Re: dhcp address?


sorry i did not include that information, but here it is.

the 2500 router has two ethernet ports eth0 and eth1

the 2500 connects my isp's router via a crossover cable (mdi.x) and in pluged in to eth0 (rj45)

the internal network is plugged in to eth1 (coax/thin net, what ever you want to call it)

eth0 is the port that is given the dhcp information and reconfigured, hopefuly, automatically.

i dont know how i configure eth0 to reconfigure its self with the dhcp information, so please could you tell me what commands i need to type to get this to work.

once again i thank you for your time

Steve keners

CreatePlease to create content