Changing net.sctp.rto_max causes the wrong value of net.sctp.rto_min

Issue

• Customer tried to change sctp related parameters.

• At first, it was something like below:

  [PCRF_00_00_FNC1:/root] sysctl -a |grep sctp
  net.sctp_wmem = 4096    16384   4194304
  net.sctp_rmem = 4096    409500  4194304
  net.sctp_mem = 933888   1245184 1867776
  net.sctp.prsctp_enable = 1
  net.sctp.addip_enable = 0
  net.sctp.rto_beta_exp_divisor = 2
  net.sctp.rto_alpha_exp_divisor = 0
  net.sctp.cookie_preserve_enable = 0
  net.sctp.hb_interval = 30000
  net.sctp.max_init_retransmits = 8
  net.sctp.path_max_retrans = 5
  net.sctp.rcvbuf_policy = 0
  net.sctp.sndbuf_policy = 0
  net.sctp.association_max_retrans = 0
  net.sctp.max_burst = 4
  net.sctp.valid_cookie_life = 60000
  net.sctp.rto_max = 0
  net.sctp.rto_min = 0
  net.sctp.rto_initial = 1000
  

• After applying below commands, it net.sctp.rto_min shows the wrong value

  [PCRF_00_00_FNC1:/root] sysctl net.sctp.rto_min=1000            
  net.sctp.rto_min = 1000
  [PCRF_00_00_FNC1:/root] sysctl net.sctp.rto_max=60000           
  net.sctp.rto_max = 60000
  [PCRF_00_00_FNC1:/root] sysctl -a|grep sctp                    
  net.sctp_wmem = 4096    16384   4194304
  net.sctp_rmem = 4096    409500  4194304
  net.sctp_mem = 933888   1245184 1867776
  net.sctp.prsctp_enable = 1
  net.sctp.addip_enable = 0
  net.sctp.rto_beta_exp_divisor = 2
  net.sctp.rto_alpha_exp_divisor = 0
  net.sctp.cookie_preserve_enable = 0
  net.sctp.hb_interval = 30000
  net.sctp.max_init_retransmits = 8
  net.sctp.path_max_retrans = 5
  net.sctp.rcvbuf_policy = 0
  net.sctp.sndbuf_policy = 0
  net.sctp.association_max_retrans = 0
  net.sctp.max_burst = 4
  net.sctp.valid_cookie_life = 60000
  net.sctp.rto_max = 60000
  net.sctp.rto_min = 257698037761000
  net.sctp.rto_initial = 429496729700