Label Distribution Method and Device

A label distribution method, comprising:

• receiving, by a second routing device, a first Border Gateway Protocol (BGP) update message sent by a first routing device, wherein the first BGP update message comprises a first virtual private network (VPN) instance identifier and a first route target (RT), wherein the first VPN instance identifier is used to identify a first VPN instance on the first routing device, and the first RT is an RT of the first VPN instance;
• sending, by the second routing device, a second BGP update message to the first routing device after determining that the first RT is equal to a second RT, wherein the second BGP update message comprises a second VPN instance identifier and the second RT, wherein the second VPN instance identifier is used to identify a second VPN instance on the second routing device, and the second RT is an RT of the second VPN instance;
• and
• receiving, by the second routing device, a third BGP update message sent by the first routing device, wherein the third BGP update message comprises a first VPN instance label, wherein the first VPN instance label is a VPN instance label that is allocated by the first routing device to the second VPN instance after determining that the first RT is equal to the second RT.

A routing device, comprising:

• a processor;
• and
• a computer-readable storage medium storing instructions to be executed by the processor, such that the processor is programmed to perform a label distribution method by:
• sending a first Border Gateway Protocol (BGP) update message to a second routing device, wherein the first BGP update message comprises a first virtual private network (VPN) instance identifier and a first route target (RT), wherein the first VPN instance identifier is used to identify a first VPN instance on the routing device, and the first RT is an RT of the first VPN instance;
• receiving a second BGP update message sent by the second routing device, wherein the second BGP update message comprises a second VPN instance identifier and a second RT, wherein the second VPN instance identifier is used to identify a second VPN instance on the second routing device and the second RT is an RT of the second VPN instance, and wherein the second BGP update message is sent by the second routing device after the second routing device determines that the first RT is equal to the second RT;
• allocating a first VPN instance label to the second VPN instance after determining that the first RT is equal to the second RT;
• and
• sending a third BGP update message to the second routing device, wherein the third BGP update message comprises the first VPN instance label.

A routing device, comprising:

• a processor;
• and
• a computer-readable storage medium storing instructions to be executed by the processor, such that the processor is programmed to perform a label distribution method by:
• Receiving a first Border Gateway Protocol (BGP) update message sent by a first routing device, wherein the first BGP update message comprises a first virtual private network (VPN) instance identifier and a first route target (RT), wherein the first VPN instance identifier is used to identify a first VPN instance on the first routing device, and the first RT is an RT of the first VPN instance;
• sending a second BGP update message to the first routing device after determining that the first RT is equal to a second RT, wherein the second BGP update message comprises a second VPN instance identifier and the second RT, wherein the second VPN instance identifier is used to identify a second VPN instance on the routing device, and the second RT is an RT of the second VPN instance;
• and
• receiving a third BGP update message sent by the first routing device, wherein the third BGP update message comprises a first VPN instance label, wherein the first VPN instance label is a VPN instance label that is allocated by the first routing device to the second VPN instance after determining that the first RT is equal to the second RT.