dhcp for isp

[carl_townshend]

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 ?

[vladrac-ccna]

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:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a00800f0804.shtml#casestudy2

Hope this helps,

if so, please rate my post.

Vlad

[carl_townshend]

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

[vladrac-ccna]

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?

vlads