Loopback Detection
CISCO: https://www.cisco.com/c/ja_jp/support/docs/content-networking/keepalives/118390-technote-keepalive-00.html
Apresia: https://www.apresia.jp/products/ent/np/usersguide/layer2/top.html?p=NP_loop_c_sp.html
allied-telesis CentreCOM GS950: https://www.allied-telesis.co.jp/support/list/switch/gs950/002152f/docs/overview_00040_Bridge_0040_LoopbackDetection.html
Huawei – LDT and LBDT Configuration http://support.huawei.com/enterprise/docinforeader!loadDocument1.action?contentId=DOC1000088877&partNo=10232 http://support.huawei.com/enterprise/docinforeader!loadDocument1.action?contentId=DOC1000112303&partNo=10232
YAMAHA http://www.rtpro.yamaha.co.jp/SW/docs/swx2310p/Rev_2_02_06/layer2/layer2_loop_detect.html?rev=2.02.06&category=layer2
検出するにはEthernetヘッダ内のEthernet Type Numberを見るのが基本的な模様
https://www.infraexpert.com/study/tea13.htm https://en.wikipedia.org/wiki/MAC_address#Address_details