1. DHCP and DNS a) IP address of the host: 130.233.46.218 DNS name of the host: dhcp-pr-8.tml.hut.fi IP address of the DNS server used: 130.233.16.3 IP address of the DHCP server used: 130.233.46.1 b) in a separate file c) The host is allowed to use the given IP address for seven days. 2. SMTP a) in a separate file b) Email control information consists of recipient and sender email addresses. They are given with RCPT and MAIL commands. In the TCPdump file frames 75 and 77 include these commands. The delivered message is given after a DATA command. In the TCPdump file frames 83 and 85 include the delivered message. c) Part of the TCP segments are acknowledgements for the data received. If the receiver has no application data to send the TCP segment can be sent without payload. 3. Other Traffic a) The packet seems to have come out from nowhere. The TCP connection has not been established. The reason for that may be for example that the connection was already established before the beginning of the TCPdump file. b) Files www.tml.hut.fi/ index page, www.tml.hut.fi/Opinnot/ index page and www.tml.hut.fi/styles/Kuvia/kennoop.gif were requested by HTTP. 4. Email Message a) Date: Mon, 20 Sep 2004 12:56:12 +0300 (EEST) From: Aaro Assari X-X-Sender: liia@peak.local To: Arttu Assari Subject: Penguins Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII "If penguins are so smart, then why do they live in iglos?" -Unknown b) It was not required to mention the corresponding RFC in this question. Yes: * email address of the sender (From, RFC 2822) * time the message was sent (Date, RFC 2822) * the mail exchange servers via which the message arrived (Received, RFC 2821) * IP address of the sender (Received, RFC 2821) * SMTP server the sender used (Received, RFC 2821) Maybe: * name of the sender (From, RFC 2822) * email client the sender used (an optional header, e.g. User Agent, RFC 2822) * name of the recipient (To, RFC 2822) * email address of the recipient (To, RFC 2822) * possible other recipients (Cc / Bcc, RFC 2822) c) In the email messages of the real world there very often occurs something that is incorrect according to the RFCs.