I'm working with a VxWorks PPP server running on an embedded system. There seems to be a problem with IPCP DNS negotiation. Each time the PPP server offers a IPCP to a client, the client seems to be rejecting the DNS1 and DNS2 fields and is accepting the IP address.
I tried with a windows dial up connection ( with 'automatically request dns' option) and an Ubuntu pppoed client (with 'usepeerdns' option). In both cases the clients are configured to obtain the DNS from the PPP server.
The packet sequence are as follows:
- Client sends IPCP Configure-Request with IP, DNS1 and DNS2 set to 0.
- Server sends IPCP Configure-Request with the relevant IP, DNS1 and DNS2 in the options field.
- Client sends Configure-Reject (Code 0x04) with DNS1 and DNS2 in the payload.
- Server sends IPCP Configure-Request with just the IP. Handshaking completes with a ACK and both agreeing on just the IP address.
I'm not really sure where this is going wrong.
Any help is much appreciated! Thanks!