Re: proxy relay agent

[Jonathan Wenocur <[e-mail]>]

>> How does it depend on the PPP client at the dial-in client end? Can't the whole
>> process be handled by the proxy DHCP client as a part of IPCP negotiation?
>> But the questions arise whether the dial-in client will wait for say 2 minutes
>> (in the worst case) for IPCP negotiation? Also what action should be taken when 
>> lease for the dial-in client expires (since it could not be renewed for any 
>> reason)? It is not proper to break the connection abruptly. Then what should be
>> done? 
>>      Any thoughts on these issues will be highly appreciated.

What I was alluding to in the last mail was that if you want the
dial-in client to use DHCP to obtain its IP address then there is a
timing issue since IPCP may not be up by the time DHCP tries to get
the address.  This is one of the reasons we use the proxy client
method.  In the proxy client case the remote access server is doing
the DHCP work and, as you say, passes the IP address back to the
dial-in client using IPCP.  It's up to the dial-in client to know how
to take that address and force it down into the IP stack, which is not
necessarily that easy (and I don't know whow it's done, the client
software folks handle that end).

In the case of lease expiration you have no choice but to bring down
IPCP since the IP address is no longer valid.  Even if you could
obtain a new address it's not necessarily possible to force a new
address into the IP stack at the dial-in client end, and even if you
succeed in doing _that_ you still lose all current IP activity anyway
since the address changed.  (By the way, if other NCPs are running
over the connection you don't have to bring those down, only IPCP.)

-- Jonathan