1Tunnel metadata manipulation actionTuinnLnietnlcu(xm8e)tadata manipulation action in tc(8)
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6 tunnel_key - Tunnel metadata manipulation
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9 tc ... action tunnel_key { unset | SET }
10 SET := set src_ip ADDRESS dst_ip ADDRESS id KEY_ID dst_port UDP_PORT
12 tos TOS ttl TTL [ csum | nocsum ]
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16 The tunnel_key action combined with a shared IP tunnel device, allows
17 to perform IP tunnel en- or decapsulation on a packet, reflected by the
18 operation modes UNSET and SET. The UNSET mode is optional - even with‐
19 out using it, the metadata information will be released automatically
20 when packet processing will be finished. UNSET function could be used
21 in cases when traffic is forwarded between two tunnels, where the meta‐
22 data from the first tunnel will be used for encapsulation done by the
23 second tunnel. SET mode requires the source and destination ip ADDRESS
24 and the tunnel key id KEY_ID which will be used by the ip tunnel shared
25 device to create the tunnel header. The tunnel_key action is useful
26 only in combination with a mirred redirect action to a shared IP tunnel
27 device which will use the metadata (for SET ) and unset the metadata
28 created by it (for UNSET ).
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32 unset Unset the tunnel metadata created by the IP tunnel device. This
33 function is not mandatory and might be used only in some spe‐
34 cific use cases (as explained above).
35 set Set tunnel metadata to be used by the IP tunnel device. Requires
37 id , src_ip and dst_ip options. dst_port and geneve_opts are
38 optional.
39 id Tunnel ID (for example VNI in VXLAN tunnel)
41 src_ip Outer header source IP address (IPv4 or IPv6)
43 dst_ip Outer header destination IP address (IPv4 or IPv6)
45 dst_port
47 Outer header destination UDP port
48 geneve_opts
50 Geneve variable length options. geneve_opts is specified
51 in the form CLASS:TYPE:DATA, where CLASS is represented
52 as a 16bit hexadecimal value, TYPE as an 8bit hexadecimal
53 value and DATA as a variable length hexadecimal value.
54 Additionally multiple options may be listed using a comma
55 delimiter.
56 tos Outer header TOS
58 ttl Outer header TTL
60 [no]csum
62 Controlls outer UDP checksum. When set to csum (which is
63 default), the outer UDP checksum is calculated and
64 included in the packets. When set to nocsum, outer UDP
65 checksum is zero. Note that when using zero UDP checksums
66 with IPv6, the other tunnel endpoint must be configured
67 to accept such packets. In Linux, this would be the
68 udp6zerocsumrx option for the VXLAN tunnel interface.
69 If using nocsum with IPv6, be sure you know what you are
71 doing. Zero UDP checksums provide weaker protection
72 against corrupted packets. See RFC6935 for details.
73
75 The following example encapsulates incoming ICMP packets on eth0 into a
76 vxlan tunnel, by setting metadata to VNI 11, source IP 11.11.0.1 and
77 destination IP 11.11.0.2, and by redirecting the packet with the meta‐
78 data to device vxlan0, which will do the actual encapsulation using the
79 metadata:
80 #tc qdisc add dev eth0 handle ffff: ingress
82 #tc filter add dev eth0 protocol ip parent ffff: \
83 flower \
84 ip_proto icmp \
85 action tunnel_key set \
86 src_ip 11.11.0.1 \
87 dst_ip 11.11.0.2 \
88 id 11 \
89 action mirred egress redirect dev vxlan0
90 Here is an example of the unset function: Incoming VXLAN traffic with
92 outer IP's and VNI 11 is decapsulated by vxlan0 and metadata is unset
93 before redirecting to tunl1 device:
94 #tc qdisc add dev eth0 handle ffff: ingress
96 #tc filter add dev vxlan0 protocol ip parent ffff: flower \
97 enc_src_ip 11.11.0.2 enc_dst_ip 11.11.0.1 enc_key_id 11 action tunnel_key unset action mirred egress redirect dev tunl1
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101 tc(8)
102iproute2 1T0unNnoevl 2m0e1t6adata manipulation action in tc(8)