Indicates
the type of a change.
MULTIPLE_P2P_AD: indicates that repeated P2P neighbors appear.
L1_CIRCUIT_DOWN: indicates that the Level-1 interface is Down.
L2_CIRCUIT_DOWN: indicates that the Level-2 interface is Down.
CIRCUIT_DOWN: indicates that the P2P interface is Down.
CLEAR_L1_NEIGHBOUR: indicates that the Level-1 neighbor changes
after the undo isis command is used.
CLEAR_L2_NEIGHBOUR: indicates that the Level-2 neighbor changes
after the undo isis command is used.
CLEAR_NEIGHBOUR: indicates that the P2P neighbor changes after
the undo isis command is used.
P2P_HOLDTIMER_EXPIRED: indicates the P2P neighbor times out.
L1_HOLDTIMER_EXPIRED: indicates that the Level-1 neighbor times
out.
L2_HOLDTIMER_EXPIRED: indicates that the Level-2 neighbor times
out.
NEW_L1_ADJ: indicates a new Level-1 neighbor.
NEW_L2_ADJ: indicates a new Level-2 neighbor.
USGAGE_MISMATCH: indicates that the type of the neighbor is
different from that of the Hello message.
UPDT_LSP_FAILED: indicates that updating the neighbor status
in the LSP fails.
NO_MEMORY_FOR_HIGER_PRIORITY_ADJ: indicates that there is no
available memory for neighbors with high priorities.
DIFFERENT_NET: indicates that the network address of the neighbor
changes.
P2P_CIRCUIT_ID_CONFLT: indicates that IDs of P2P interfaces
conflict.
NEW_ADJ: indicates a new P2P neighbor.
AREA_MISMATCH: indicates the area address of the neighbor does
not match the local area address.
3_WAY_DOWN: indicates that the neighbor is Down during three-way
handshake.
3_WAY_INIT: indicates that the neighbor is Init during three-way
handshake.
3_WAY_UP: indicates that the neighbor is Up during three-way
handshake.
P2P_INIT_MEMORY_SHORTAGE: indicates that the memory is not
enough and the P2P neighbor is in the init state.
PROTOCOL_V4_6_TO_V4: indicates that the neighbor type changes
from IPv4 and IPv6 to IPv4.
PROTOCOL_V4_6_TO_V6: indicates that the neighbor type changes
from IPv4 and IPv6 to IPv6.
PROTOCOL_V4_TO_V4_6: indicates that the neighbor type changes
from IPv4 to IPv4 and IPv6.
PROTOCOL_V6_TO_V4_6: indicates that the neighbor type changes
from IPv6 to IPv4 and IPv6.
PROTOCOL_V4_TO_V6: indicates that the neighbor type changes
from IPv4 to IPv6.
PROTOCOL_V6_TO_V4: indicates that the neighbor type changes
from IPv6 to IPv4.
L1_BFD_DOWN: indicates that Level-1 BFD is Down.
L2_BFD_DOWN: indicates that Level-2 BFD is Down.
L12_BFD_DOWN: indicates that Level-1-2 BFD is Down.
TUNNEL_LEVEL_CHANGE: indicates that the tunnel level changes.
TUNNEL_L1_NEW: indicates that a Level-1 tunnel neighbor is
generated.
TUNNEL_L2_NEW: indicates that a Level-2 tunnel neighbor is
generated.
TUNNEL_L1_DOWN: indicates the Level-1 tunnel neighbor is Down.
TUNNEL_L2_DOWN: indicates the Level-2 tunnel neighbor is Down.
TUNNEL_L2_TO_L12: indicates that the neighbor changes from
a Level-2 neighbor to a Level-1-2 neighbor.
TUNNEL_L1_TO_L12: indicates that the neighbor changes from
a Level-1 neighbor to a Level-1-2 neighbor.
NEW_ADJ_CREATE: indicates that a new neighbor is generated.
NO_COMMON_TOPOLOGY: indicates that the topology information
carried in the received Hello message is different from that of the
neighbor.
REMOTE_IS_PACKET_CHANGED: indicates that the Hello message
sent by the remote neighbor changes.
NO_SNPA_IN_IIH: indicates that the received Hello message does
not contain the SNPA address.