Add documentation for new IOAM sysctls:
- ioam6_id and ioam6_id_wide: two per-namespace sysctls
- ioam6_enabled, ioam6_id and ioam6_id_wide: three per-interface sysctls
Example of IOAM configuration based on the following simple topology:
_____ _____ _____
| | eth0 eth0 | | eth1 eth0 | |
| A |.----------.| B |.----------.| C |
|_____| |_____| |_____|
1) Node and interface IDs can be configured for IOAM:
# IOAM ID of A = 1, IOAM ID of A.eth0 = 11
(A) sysctl -w net.ipv6.ioam6_id=1
(A) sysctl -w net.ipv6.conf.eth0.ioam6_id=11
# IOAM ID of B = 2, IOAM ID of B.eth0 = 21, IOAM ID of B.eth1 = 22
(B) sysctl -w net.ipv6.ioam6_id=2
(B) sysctl -w net.ipv6.conf.eth0.ioam6_id=21
(B) sysctl -w net.ipv6.conf.eth1.ioam6_id=22
# IOAM ID of C = 3, IOAM ID of C.eth0 = 31
(C) sysctl -w net.ipv6.ioam6_id=3
(C) sysctl -w net.ipv6.conf.eth0.ioam6_id=31
Note that "_wide" IDs equivalents can be configured the same way.
2) Each node can be configured to form an IOAM domain. For instance,
we allow IOAM from A to C only (not the reverse path), i.e. enable
IOAM on ingress for B.eth0 and C.eth0:
(B) sysctl -w net.ipv6.conf.eth0.ioam6_enabled=1
(C) sysctl -w net.ipv6.conf.eth0.ioam6_enabled=1
3) An IOAM domain (e.g. ID=123) is defined and made known to each node:
(A) ip ioam namespace add 123
(B) ip ioam namespace add 123
(C) ip ioam namespace add 123
4) Finally, an IOAM Pre-allocated Trace can be inserted in traffic sent
by A when C (e.g. db02::2) is the destination:
(A) ip -6 route add db02::2/128 encap ioam6 trace type 0x800000 ns 123
size 12 dev eth0
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
