Advertising with a layer three routing protocol constituent link attributes of a layer two bundle

A network device comprising:

• a control unit comprising one or more processors;
• one or more forwarding units each having one or more interfaces, coupled to respective physical links, to exchange packet data units with other network devices of a network;
• a management interface of the control unit that receives configuration information that specifies first and second constituent links for a layer two (L2) aggregated interface, wherein the first and second constituent links are physical links connected to respective physical interfaces of the forwarding units;
• and
• a routing protocol daemon of the control unit that generates a link state message that specifies layer three (L3) routing information associated with the aggregated interface and includes a first sub-type-length-value (sub-TLV) that specifies an attribute of the first constituent link of the aggregated interface and a second sub-type-length-value (sub-TLV) that specifies an attribute of the second constituent link of the aggregated interface,
• wherein the routing protocol daemon sends the link state message from the network device to another network device of the network in accordance with a routing protocol.

A network device comprising:

• a control unit comprising one or more processors;
• and
• a routing protocol daemon of the control unit that receives a link state message in accordance with a routing protocol for a layer two (L2) aggregated interface having first and second constituent links, wherein the link state message specifies layer three (L3) routing information associated with the aggregated interface and includes a first sub-type-length-value (sub-TLV) that specifies an attribute of a first constituent link of the aggregated interface and a second sub-type-length-value (sub-TLV) that specifies an attribute of a second constituent link of the aggregated interface,
• wherein the routing protocol daemon computes a path through a network that includes the first constituent link when the attribute of the first constituent link satisfies a computation constraint for the path and the attribute of the second constituent link does not satisfy the computation constraint.