TCP IP Illustrated

119 no we saw in section 1112 that many

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: am becomes 17 frames across the SLIP link. 11.5 No. The problem is that when the application times out and retransmits, the IP datagram generated by the retransmission has a new identification field. Reassembly is done only for fragments with the same identification field. 11.6 The identification field in the IP header (47942) is the same. 11.7 First, from Figure 11.4 we see that gemini does not have outgoing UDP checksums enabled. It's highly probable that the operating system on this host (SunOS 4.1.1) is one that never verifies an incoming UDP checksum unless outgoing UDP checksums are enabled. Second, it could be that most of the UDP traffic is local traffic, instead of WAN traffic, and therefore not subject to all the vagaries of WANs. 11.8 The loose and strict source routing options are copied into each fragment. The timestamp option and the record route option are not copied into each fragment-they appear only in the first fragment. 11.9 No. We saw in Section 11.12 that many implementations can filter incoming datagrams destined for a given UDP port number based on the destination IP address, source IP address, and source port number. Chapter 12 12.1 Broadcasting by itself does not add to network traffic, but it adds extra host processing. Broadcasting can lead to additional network traffic if the receiving hosts incorrectly respond with errors such as ICMP port unreachables. Also, routers normally don't forward broadcast packets, whereas bridges normally do, so broadcasts on a bridged network can travel much farther than they would on a routed network. 12.2 Every host receives a copy of every broadcast. The interface layer receives the frame, and passes it to the device driver. If the type field is for some other protocol, it is the device driver that discards the frame. 12.3 First execute netstat -r to see the routing table. This shows the names of all the interfaces. Then execute ifconfig (Section 3.8) for each interface: the flags tell if the interface supports broadcasting, and if so t...
View Full Document

This test prep was uploaded on 04/04/2014 for the course ECE EL5373 taught by Professor Guoyang during the Spring '12 term at NYU Poly.

Ask a homework question - tutors are online