We introduce the new "End.DT46" action for supporting the SRv6 End.DT46
Behavior in iproute2.
The SRv6 End.DT46 Behavior, defined in RFC 8986 [1] section 4.8, can be
used to implement L3 VPNs based on Segment Routing over IPv6 networks in
multi-tenants environments and it is capable of handling both IPv4 and
IPv6 tenant traffic at the same time.
The SRv6 End.DT46 Behavior decapsulates the received packets and it
performs the IPv4 or IPv6 routing lookup in the routing table of the
tenant.
As for the End.DT4 and for the End.DT6 in VRF mode, the SRv6 End.DT46
Behavior leverages a VRF device in order to force the routing lookup into
the associated routing table using the "vrftable" attribute.
To make the End.DT46 work properly, it must be guaranteed that the
routing table used for routing lookup operations is bound to one and
only one VRF during the tunnel creation. Such constraint has to be
enforced by enabling the VRF strict_mode sysctl parameter, i.e.:
$ sysctl -wq net.vrf.strict_mode=1
Note that the same approach is used for the End.DT4 Behavior and for the
End.DT6 Behavior in VRF mode.
An SRv6 End.DT46 Behavior instance can be created as follows:
$ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100
Standard Output:
$ ip -6 route show 2001:db8::1
2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100 metric 1024 pref medium
JSON Output:
$ ip -6 -j -p route show 2001:db8::1
[ {
"dst": "2001:db8::1",
"encap": "seg6local",
"action": "End.DT46",
"vrftable": 100,
"dev": "vrf100",
"metric": 1024,
"flags": [ ],
"pref": "medium"
} ]
This patch updates the route.8 man page and the ip route help with the
information related to End.DT46.
Considering that the same information was missing for the SRv6 End.DT4 and
the End.DT6 Behaviors, we have also added it.
[1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Paolo Lungaroni <paolo.lungaroni@uniroma2.it>
Signed-off-by: David Ahern <dsahern@kernel.org>
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