draft-ietf-nvo3-geneve-08 says: It is strongly RECOMMENDED that Path MTU Discovery ([RFC1191], [RFC1981]) be used by setting the DF bit in the IP header when Geneve packets are transmitted over IPv4 (this is the default with IPv6). Now that ICMP error handling is working for GENEVE, we can comply with this recommendation. Make this configurable, though, to avoid breaking existing setups. By default, DF won't be set. It can be set or inherited from inner IPv4 packets. If it's configured to be inherited and we are encapsulating IPv6, it will be set. This only applies to non-lwt tunnels: if an external control plane is used, tunnel key will still control the DF flag. v2: - DF behaviour configuration only applies for non-lwt tunnels, apply DF setting only if (!geneve->collect_md) in geneve_xmit_skb() (Stephen Hemminger)
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| @@ -566,10 +566,19 @@ enum { · 565 unmodified lines | ||
| 566 | 566 | IFLA_GENEVE_UDP_ZERO_CSUM6_RX, |
| 567 | 567 | IFLA_GENEVE_LABEL, |
| 568 | 568 | IFLA_GENEVE_TTL_INHERIT, |
| 569 | + IFLA_GENEVE_DF, | |
| 569 | 570 | __IFLA_GENEVE_MAX |
| 570 | 571 | }; |
| 571 | 572 | #define IFLA_GENEVE_MAX (__IFLA_GENEVE_MAX - 1) |
| 572 | 573 | |
| 574 | +enum ifla_geneve_df { | |
| 575 | + GENEVE_DF_UNSET = 0, | |
| 576 | + GENEVE_DF_SET, | |
| 577 | + GENEVE_DF_INHERIT, | |
| 578 | + __GENEVE_DF_END, | |
| 579 | + GENEVE_DF_MAX = __GENEVE_DF_END - 1, | |
| 580 | +}; | |
| 581 | + | |
| 573 | 582 | /* PPP section */ |
| 574 | 583 | enum { |
| 575 | 584 | IFLA_PPP_UNSPEC, |