老大,HELP!问两个问题

sky

RouterTK#show ip route<br>Codes: C-connected, s-static, l -IGRP, R -RIP, M -mobile, B -BGP, D -EIGRP, EX - EIGRP external,<br>O - OSPF, IA -OSPF inter area, EI -OSPF external type 1, E2 -OSPF external type 2, E -EGP,<br>i -IS-IS, L1 -IS-IS level-1, L2 -IS-IS level-2, * -candidate default, U - per-user static<br>route<br>Gateway of last resort is not set<br>R 202.30.8.0 /24[120/1] via 202.30.2.2, 00:00:16, Serial 0<br>C 202.30.9.0 /24 is directly connected, Serial 1<br>R 202.30.10.0 /24 is possibly down, routing via 202.30.9.1, Serial 1<br>R 202.30.11.0 /24 is possibly down, routing via 202.30.9.1, Serial 1<br>C 202.30.1.0 /24 is directly connected, Ethernet 0<br>C 202.30.2.0 /24 is directly connected, Serial 0<br>R 202.30.3.0 /24 [120/1] via 202.30.2.2, 00:00:17. Serial 0<br>R 202.30.4.0 /24 [120/15/ via 202.30.2.2, 00:00:17, Serial 0<br>R 202.30.5.0 /24 [120/15] via 202.30.2.2, 00:00:17, Serial 0<br>R 192.158.6.0 /24 [120/15] via 202.30.2.2, 00:00:17, Serial 0<br>R 202.30.7.0 /24 [120/1] via 202.30.2.2, 00:00:17, Serial 0<br>640 - 607<br>Leading the way in IT testing and certification tools, www.testking.com<br>- 222 -<br>You are troubleshooting a router with default settings. You are concerned about the 202.30.10.0 and<br>202.30.11.0 routes. In particular you are interested how long they will be kept in the routing table. What<br>would be the maximum time these routes would be kept in the routing table?<br>A. 30 seconds<br>B. 60 seconds<br>C. 240 seconds<br>D. 360 seconds<br>E. 630 seconds<br>Answer: C<br><br>老大,这题还是不太明白啊!<br><br>另外:&quot;bit-oriented protocols include SDLC,LLC,HDLC,TCP,IP,ect.&quot;<br>bit-oriented protocol是什么?<IMG border=0 SRC=http://www.spoto.net/bbs/images/brow/sad_smile.gif>

ahaha

RIP协议的生存时间拉。<br>

chinamoon

有几个时间Hold time, flush time, update time.找找资料理解一下.<br>R 202.30.10.0 /24 is possibly down, routing via 202.30.9.1, Serial 1<br>这条链路down了.所以,经过rip路由协议flush time以后,这条路由就从路由表移除了.<br>

sky

&quot;The hold down timer for RIP is 180 sec. The flush timer for RIP is 240 sec.&quot;<br>跟这个有什么联系?

ahaha

HOLD TIME是保持时间，这段时间里会保持路由表并不断发包询问，在询问得不到消息后，FLUSH TIME，路由被清楚。

sky

&quot;bit-oriented protocols include SDLC,LLC,HDLC,TCP,IP,ect.&quot;<br>bit-oriented protocol是什么?

ahaha

Bit-oriented protocol <br><br>面向比特协议 能不管帧内容而传送帧的数据链路层通讯协议类别。与面向字节协议相比，面向比特协议提供全双工操作并更加高效和可靠<br>

chinamoon

<BLOCKQUOTE><strong>引用</strong>：<HR Size=1>原文由 <b>ahaha</b> 发表:<br>HOLD TIME是保持时间，这段时间里会保持路由表并不断发包询问，在询问得不到消息后，FLUSH TIME，路由被清楚。<HR SIZE=1></BLOCKQUOTE><br><br>Very Very 正确.

sky

谢谢两位啦!

chinamoon

谢ahaha吧.他很久未出江湖了. :)