概要 †
Linux †
ネットワーク †
- dial tcp: i/o timeout
- netcontrack テーブルが足りていなかったりする
- Ephemeral port exhaustion
ネットワーク †
L7 †
- https の URL に投げるときは、-k をつけないと証明書周りで怒られる
- -w をつけると、DNS や TLS ハンドシェイクなどの時間を見ることができる。
```
curl -v -k -w 'lookup: %{time_namelookup}
connect: %{time_connect}
appconnect: %{time_appconnect}
pretransfer: %{time_pretransfer}
redirect: %{time_redirect}
starttransfer: %{time_starttransfer}
total: %{time_total}
' https://www.google.com/
```
```
curl -v -k -w 'lookup: %{time_namelookup}
connect: %{time_connect}
appconnect: %{time_appconnect}
pretransfer: %{time_pretransfer}
redirect: %{time_redirect}
starttransfer: %{time_starttransfer}
total: %{time_total}
' 123.45.67.89
```
L4 †
- traceroute
- Timeouts at the very end of the report
- The target's firewall may be blocking requests. The target is still most probably reachable with a normal HTTP request, however. This should not affect normal connection.
- The return path may have an issue from the destination point. This would mean the signal is still reaching, but just not getting the return signal back to your computer. This should not affect normal connection.
- これは異なる復路を使っていてそこでレイテンシが発生しているということ
- Possible connection problem at the target. This will affect the connection.
![[PukiWiki]](image/pukiwiki.png "[PukiWiki]")
