nsip - software network interface encapsulating NS packets
in IP packets
option NSIP
#include <netns/ns_if.h>
The nsip 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
OpenBSD IP machinery.
The superuser 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 interface 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 following 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;
};
nsip%d: can't handle af%d. The interface was handed a message with addresses
formatted in an unsuitable address family; the packet was
dropped.
netintro(4), ns(4)
The nsip interface appeared in 4.3BSD.
It is absurd to have a separate pseudo-device for each ptto-pt link.
There is no way to change the IP address for an NS host once
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 universities.
OpenBSD 3.6 November 30, 1993
[ Back ] | 