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New Member

dhcp for isp

Can anyone tell me how the isp issues dhcp addresses, because surely from where they are issuing them there will be plenty of routers it has to pass before i recieve the offer at home, how it this dhcp traffic passed on to me ?


Re: dhcp for isp

Hello Carl,

DHCP works only on the LAN, I mean your host only broadcast messages and hopes it reaches a server on the LAN.

In order to have a server on a different LAN (or on a different router) they need to configure 2 things:

service dhcp

ip helper-address _> this will unicast your broadcast msg to the dhcp server.

really good link would be:

Hope this helps,

if so, please rate my post.


New Member

Re: dhcp for isp

Sorry I meant how does my router receive its wan address ?

Re: dhcp for isp

Hello Carl

what kind of router do you have?

do you have a sample of its configuration?

what is the link between this router and the WAN? ppp? is your router set as a dhcp client?