キャプチャ結果を晒します．PPPoEサーバから何の反応も返ってきてない感じです．

# tcpdump -i fxp0
tcpdump: WARNING: fxp0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on fxp0, link-type EN10MB (Ethernet), capture size 96 bytes
12:55:40.907460 PPPoE PADI [Host-Uniq 0x40C6BAC3] [Service-Name "nifty"]
12:55:42.906706 PPPoE PADI [Host-Uniq 0x40C6BAC3] [Service-Name "nifty"]
12:55:46.906606 PPPoE PADI [Host-Uniq 0x40C6BAC3] [Service-Name "nifty"]
12:55:54.910944 PPPoE PADI [Host-Uniq 0x00C5BAC3] [Service-Name "nifty"]
12:55:56.910375 PPPoE PADI [Host-Uniq 0x00C5BAC3] [Service-Name "nifty"]
12:56:00.910286 PPPoE PADI [Host-Uniq 0x00C5BAC3] [Service-Name "nifty"]
12:56:09.912701 PPPoE PADI [Host-Uniq 0x40C0BAC3] [Service-Name "nifty"]
12:56:11.912034 PPPoE PADI [Host-Uniq 0x40C0BAC3] [Service-Name "nifty"]
12:56:15.911939 PPPoE PADI [Host-Uniq 0x40C0BAC3] [Service-Name "nifty"]
12:56:24.915262 PPPoE PADI [Host-Uniq 0xC0DB98C3] [Service-Name "nifty"]
12:56:26.914692 PPPoE PADI [Host-Uniq 0xC0DB98C3] [Service-Name "nifty"]