2.11BSD/man/cat4/nsip.0
NSIP(4) UNIX Programmer's Manual NSIP(4)
NAME
nsip - software network interface encapsulating ns packets
in ip packets.
SYNOPSIS
#include <netns/ns_if.h>
Not currently supported under 2.11BSD
DESCRIPTION
The _n_s_i_p interface is a software mechanism which may be used
to transmit Xerox NS(tm) packets through otherwise
uncooperative networks. It functions by prepending an IP
header, and resubmitting the packet through the unix IP
machinery.
The super-user can advise the operating system of a willing
partner by naming an IP address to be associated with an NS
address. Presently, only specific hosts pairs are allowed,
and for each host pair, an artificial point-to-point inter-
face is constructed. At some future date, IP broadcast
addresses or hosts may be paired with NS networks or hosts.
Specifically, a socket option of SO_NSIP_ROUTE is set on a
socket of family AF_NS, type SOCK_DGRAM, passing the follow-
ing structure:
struct nsip_req {
struct sockaddr rq_ns; /* must be ns format destination */
struct sockaddr rq_ip; /* must be ip format gateway */
short rq_flags;
};
DIAGNOSTICS
nsip%d: can't handle af%d. The interface was handed a mes-
sage with addresses formatted in an unsuitable address fam-
ily; the packet was dropped.
SEE ALSO
intro(4N), ns(4F)
BUGS
It is absurd to have a separate pseudo-device for each pt-
to-pt link. There is no way to change the IP address for an
NS host once the the encapsulation interface is set up. The
request should honor flags of RTF_GATEWAY to indicate remote
networks, and the absence of RTF_UP should be a clue to
remove that partner. This was intended to postpone the
necessity of rewriting reverse ARP for the en device, and to
allow passing XNS packets through an Arpanet-Milnet gateway,
to facilitate testing between some co-operating
Printed 11/26/99 January 27, 1996 1
NSIP(4) UNIX Programmer's Manual NSIP(4)
universities.
Printed 11/26/99 January 27, 1996 2