6in4 2.3 KB

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  1. .TH 6IN4 8
  2. .SH NAME
  3. 6in4 - 6to4 tunnel of IPv6 through IPv4
  4. .SH SYNOPSIS
  5. .B ip/6in4
  6. [
  7. .B -ag
  8. ] [
  9. .B -x
  10. .I netmtpt
  11. ] [
  12. .IB local6[ / mask]
  13. [
  14. .I remote4
  15. [
  16. .I remote6
  17. ] ] ]
  18. .SH DESCRIPTION
  19. .I 6in4
  20. sets up and operates a tunnel of IPv6 traffic through an IPv4 connection.
  21. .PP
  22. .I Local6
  23. and
  24. .I mask
  25. define the IPv6 address and subnet of the near end of the tunnel
  26. .RI ( mask
  27. defaults to
  28. .L /128
  29. for a single-host
  30. tunnel).
  31. If
  32. .I local6
  33. is missing or
  34. .LR - ,
  35. it defaults to
  36. .IP
  37. .BI 2002: aabb : ccdd ::1/48
  38. .PP
  39. where
  40. .IR aa ,
  41. .IR bb ,
  42. .I cc
  43. and
  44. .I dd
  45. are the hexadecimal equivalents of the bytes
  46. .IB a . b . c .\c
  47. .I d
  48. in this host's primary IPv4 address.
  49. .PP
  50. .I Remote4
  51. is the IPv4 address of the far end of the tunnel
  52. (must be given explicitly for a configured tunnel, or
  53. defaults to the anycast address 192.88.99.1 for
  54. .IR 6to4 ).
  55. .PP
  56. .I Remote6
  57. is the IPv6 address of the far end of the tunnel
  58. (used as the point-to-point destination for routing, and
  59. defaults to a link-local address constructed from
  60. .IR remote4 ).
  61. .PP
  62. .I 6in4
  63. forks a pair of background processes to copy packets to and from
  64. the tunnel.
  65. .PP
  66. Options are:
  67. .TF -x
  68. .PD 0
  69. .TP
  70. .B -a
  71. permit any remote IPv4 address as the far end of a tunnel.
  72. This is likely to be useful for the server side of a tunnel.
  73. .TP
  74. .B -g
  75. add a default route to the tunnel for global IPv6 addresses.
  76. .TP
  77. .B -x
  78. use the network mounted at
  79. .I netmtpt
  80. instead of
  81. .LR /net .
  82. .PD
  83. .SH EXAMPLES
  84. If your primary IPv4 address is public,
  85. you can start a
  86. .I 6to4
  87. tunnel simply with
  88. .IP
  89. .EX
  90. ip/6in4 -g
  91. .EE
  92. .PP
  93. Similarly, you can start a server for
  94. .I 6to4
  95. tunnels with
  96. .IP
  97. .EX
  98. ip/6in4 -ag
  99. .EE
  100. .PP
  101. If you use a tunnel broker at address
  102. .LR 5.6.7.8 ,
  103. configured to give you a
  104. .L /64
  105. subnet with address
  106. .LR 2001:1122:3344:5566:: ,
  107. you can start the tunnel with
  108. .IP
  109. .EX
  110. ip/6in4 -g 2001:1122:3344:5566::/64 5.6.7.8
  111. .EE
  112. .SH FILES
  113. .TF /net/ipmux
  114. .PD 0
  115. .TP
  116. .B /net/ipmux
  117. access to IPv6-in-IPv4 packets
  118. .TP
  119. .B /net/ipifc
  120. packet interface to IPv6 network
  121. .SH SEE ALSO
  122. .IR bridge (3),
  123. .I ipmux
  124. in
  125. .IR ip (3),
  126. .I linklocal
  127. in
  128. .IR ipconfig (8)
  129. .br
  130. .B /lib/rfc/rfc3056
  131. .br
  132. .B /lib/rfc/rfc3068
  133. .SH BUGS
  134. Needs a kernel with an
  135. .I ipmux
  136. driver.
  137. .PP
  138. The tunnel client filters addresses fairly conservatively in both directions.
  139. However it's not watertight,
  140. and may be flakey in other ways so don't put too much trust in it.