僕の備忘録(PC、UN*X、ネットワーク関連が中心)なんです。
自分の書いたところは適当(な時とか)に書き換えますので御了承を。
ping(8)の-s オプションに、少し大きい数字をくっつけてみた。
以下、-c 1で送信したpingの、送信元と送信先のモニタリング(一部メッセージ
省略)。
$ sudo tcpdump -q -n -p icmp 02:35:30.147929 IP $SEND_LOCAL_IP > $REMOTE_HOST: ICMP echo request, id 1352, seq 1, length 1480 02:35:30.148052 IP $SEND_LOCAL_IP > $REMOTE_HOST: ip-proto-1 02:35:30.148187 IP $SEND_LOCAL_IP > $REMOTE_HOST: ip-proto-1 02:35:30.148245 IP $SEND_LOCAL_IP > $REMOTE_HOST: ip-proto-1 02:35:30.148325 IP $SEND_LOCAL_IP > $REMOTE_HOST: ip-proto-1 02:35:30.148407 IP $SEND_LOCAL_IP > $REMOTE_HOST: ip-proto-1 02:35:30.148485 IP $SEND_LOCAL_IP > $REMOTE_HOST: ip-proto-1 02:35:35.273634 IP $REMOTE_HOST > $SEND_LOCAL_IP: ICMP echo reply, id 1352, seq 1, length 1480 02:35:35.273637 IP $REMOTE_HOST > $SEND_LOCAL_IP: ip-proto-1 02:35:35.273639 IP $REMOTE_HOST > $SEND_LOCAL_IP: ip-proto-1 02:35:35.274003 IP $REMOTE_HOST > $SEND_LOCAL_IP: ip-proto-1 02:35:35.274006 IP $REMOTE_HOST > $SEND_LOCAL_IP: ip-proto-1 02:35:35.274008 IP $REMOTE_HOST > $SEND_LOCAL_IP: ip-proto-1 02:35:35.274009 IP $REMOTE_HOST > $SEND_LOCAL_IP: ip-proto-1 ^C 14 packets captured 14 packets received by filter 0 packets dropped by kernel
$ sudo tcpdump -q -n -p icmp 02:35:31.161717 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ICMP echo request, id 1352, seq 1, length 1400 02:35:31.951709 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:32.591567 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:33.186511 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:33.761488 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:34.291522 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:35.066575 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:35.206178 IP $SEND_GLOBAL_IP > $REMOTE_HOST: ip-proto-1 02:35:35.206254 IP $REMOTE_HOST > $SEND_GLOBAL_IP: ICMP echo reply, id 1352, seq 1, length 1480 02:35:35.206273 IP $REMOTE_HOST > $SEND_GLOBAL_IP: ip-proto-1 02:35:35.206277 IP $REMOTE_HOST > $SEND_GLOBAL_IP: ip-proto-1 02:35:35.206279 IP $REMOTE_HOST > $SEND_GLOBAL_IP: ip-proto-1 02:35:35.206282 IP $REMOTE_HOST > $SEND_GLOBAL_IP: ip-proto-1 02:35:35.206284 IP $REMOTE_HOST > $SEND_GLOBAL_IP: ip-proto-1 ^C 14 packets captured 15 packets received by filter 1 packet dropped by kernel
回数指定でpingしておいて、ping(8)が終了した(端末から送信を終えた)
直後にモバイルルータを再起動すると、$REMOTE_HOSTに
全部は届かないことに気づいた。
すぐには届かないパケットは、ルータの中に滞留しているように見えた。
FreeBSD 10.2-RELEASE-p18。
$ dmesg | grep Removable da0: <Generic- Compact Flash 1.00> Removable Direct Access SCSI device da1: <Generic- SM/xD-Picture 1.00> Removable Direct Access SCSI device da2: <Generic- SD/MMC 1.00> Removable Direct Access SCSI device da3: <Generic- MS/MS-Pro/HG 1.00> Removable Direct Access SCSI device da4: <Generic- SD/MMC/MS/MSPRO 1.00> Removable Direct Access SCSI device
ちなみにLinux(3.13.0-93-generic, Precise)だと、
[30788.440271] scsi 2:0:0:0: Direct-Access Generic- Compact Flash 1.00 PQ: 0 ANSI: 0 CCS [30788.443225] scsi 2:0:0:1: Direct-Access Generic- SM/xD-Picture 1.00 PQ: 0 ANSI: 0 CCS [30788.446221] scsi 2:0:0:2: Direct-Access Generic- SD/MMC 1.00 PQ: 0 ANSI: 0 CCS [30788.449403] scsi 2:0:0:3: Direct-Access Generic- MS/MS-Pro/HG 1.00 PQ: 0 ANSI: 0 CCS [30788.452415] scsi 2:0:0:4: Direct-Access Generic- SD/MMC/MS/MSPRO 1.00 PQ: 0 ANSI: 0 CCS [30788.452722] sd 2:0:0:0: Attached scsi generic sg2 type 0 [30788.452899] sd 2:0:0:1: Attached scsi generic sg3 type 0 [30788.453118] sd 2:0:0:2: Attached scsi generic sg4 type 0 [30788.453293] sd 2:0:0:3: Attached scsi generic sg5 type 0 [30788.453460] sd 2:0:0:4: Attached scsi generic sg6 type 0
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