/proc/sys/net/conf/<iface>/seg6_* variables:
  
  seg6_enabled - BOOL
  	Accept or drop SR-enabled IPv6 packets on this interface.
  
  	Relevant packets are those with SRH present and DA = local.
  
  	0 - disabled (default)
  	not 0 - enabled
  
  seg6_require_hmac - INTEGER
  	Define HMAC policy for ingress SR-enabled packets on this interface.
  
  	-1 - Ignore HMAC field
  	0 - Accept SR packets without HMAC, validate SR packets with HMAC
  	1 - Drop SR packets without HMAC, validate SR packets with HMAC
  
  	Default is 0.