spb-rs2/ipv4: show protocols all NWLink

NWLink BGP --- start 2019-05-14 Connect BGP Error: Hold timer expired

Description:    NWLink/42893/AS42893
  BGP state:          Connect
    Neighbor address: 31.44.186.9
    Neighbor AS:      42893
    Last error:       BGP Error: Hold timer expired
  Channel ipv4
    State:          DOWN
    Table:          master4
    Preference:     100
    Input filter:   (unnamed)
    Output filter:  (unnamed)
    Import limit:   5000
      Action:       disable