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1 | .\" Copyright (c) 1985, 1991, 1993 |
2 | .\" The Regents of the University of California. All rights reserved. | |
ef8cc9a4 | 3 | .\" |
91cff1e1 | 4 | .\" %sccs.include.redist.man% |
ef8cc9a4 | 5 | .\" |
9323e918 | 6 | .\" @(#)nsip.4 8.2 (Berkeley) %G% |
1324d254 | 7 | .\" |
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8 | .Dd |
9 | .Dt NSIP 4 | |
10 | .Os BSD 4.3 | |
11 | .Sh NAME | |
12 | .Nm nsip | |
13 | .Nd software network interface encapsulating NS packets in IP packets | |
14 | .Sh SYNOPSIS | |
15 | .Cd options NSIP | |
16 | .Fd #include <netns/ns_if.h> | |
17 | .Sh DESCRIPTION | |
ef8cc9a4 | 18 | The |
9903e566 | 19 | .Nm nsip |
ef8cc9a4 | 20 | interface is a software mechanism which may be |
9903e566 CL |
21 | used to transmit Xerox |
22 | .Tn NS Ns (tm) | |
23 | packets through otherwise uncooperative | |
ef8cc9a4 | 24 | networks. |
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25 | It functions by prepending an |
26 | .Tn IP | |
27 | header, and resubmitting the packet | |
28 | through the | |
29 | .Tn UNIX | |
30 | .Tn IP | |
31 | machinery. | |
32 | .Pp | |
ef8cc9a4 | 33 | The super-user can advise the operating system of a willing partner |
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34 | by naming an |
35 | .Tn IP | |
36 | address to be associated with an | |
37 | .Tn NS | |
38 | address. | |
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39 | Presently, only specific hosts pairs are allowed, and for each host |
40 | pair, an artificial point-to-point interface is constructed. | |
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41 | At some future date, |
42 | .Tn IP | |
43 | broadcast addresses or hosts may be paired | |
44 | with | |
45 | .Tn NS | |
46 | networks or hosts. | |
47 | .Pp | |
48 | Specifically, a socket option of | |
49 | .Dv SO_NSIP_ROUTE | |
50 | is set on a socket | |
51 | of family | |
52 | .Dv AF_NS , | |
53 | type | |
54 | .Dv SOCK_DGRAM , | |
55 | passing the following structure: | |
56 | .Bd -literal | |
ef8cc9a4 KS |
57 | struct nsip_req { |
58 | struct sockaddr rq_ns; /* must be ns format destination */ | |
59 | struct sockaddr rq_ip; /* must be ip format gateway */ | |
60 | short rq_flags; | |
61 | }; | |
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62 | .Ed |
63 | .Sh DIAGNOSTICS | |
64 | .Bl -diag | |
65 | .It nsip%d: can't handle af%d. | |
66 | The interface was handed | |
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67 | a message with addresses formatted in an unsuitable address |
68 | family; the packet was dropped. | |
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69 | .El |
70 | .Sh SEE ALSO | |
71 | .Xr intro 4 , | |
72 | .Xr ns 4 | |
73 | .Sh HISTORY | |
74 | The | |
75 | .Nm | |
76 | interface appeared in | |
77 | .Bx 4.3 . | |
78 | .Sh BUGS | |
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79 | It is absurd to have a separate pseudo-device for each pt-to-pt |
80 | link. | |
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81 | There is no way to change the |
82 | .Tn IP | |
83 | address for an | |
84 | .Tn NS | |
85 | host once the | |
9323e918 | 86 | encapsulation interface is set up. |
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87 | The request should honor flags of |
88 | .Dv RTF_GATEWAY | |
89 | to indicate | |
90 | remote networks, and the absence of | |
91 | .Dv RTF_UP | |
92 | should be a clue | |
ef8cc9a4 | 93 | to remove that partner. |
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94 | This was intended to postpone the necessity of rewriting reverse |
95 | .Tn ARP | |
ef8cc9a4 | 96 | for the |
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97 | .Xr en 4 |
98 | device, and to allow passing | |
99 | .Tn XNS | |
100 | packets through an | |
ef8cc9a4 KS |
101 | Arpanet-Milnet gateway, to facilitate testing between some co-operating |
102 | universities. |