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Hi, But it's obviously inefficient. Is it due to some inability of PPP ? Or can you tell what reason makes the packets a round trip ? Since the router should have the information of its local interface, why should it always send packets out, the get it back ? regards, Yu Ning -----Original Message----- From: Dumb Kid <[email protected]> To: Yu Ning <[email protected]>; nanog-post <[email protected]> Date: Thursday, May 11, 2000 9:45 AM Subject: Re: Strange result while ping serial interface >Yeah , it's normal. The packet actually travels to the >other end of the router over the serial and back. >That's why the response time is doubled. > > > >--- Yu Ning <[email protected]> wrote: >> >> Hi nanog, >> >> Strange thing happens everyday. When I were >> troubleshooting yestoday, >> I found a ping to my local serial interface (no >> matter it's 155M POS, >> or 2M Serial interface) takes nearly twice delay >> compared with a ping >> to the remote side of the serial interrface ! When I >> trace to my local >> serial interface, I got the first hop to the remote >> end, then second >> hop back to my local interface ! >> >> For example, 202.97.2.1 is local serial interface, >> while 2.2 is remote >> side. A trace on 2.1 to 2.1 first go to 2.2, then >> back to 2.1. And this >> situation can be verified on both side. >> >> Have you ever seen this situation ? Is it due to our >> misconfiguration? >> or it's sheerly a mis-display of result in Cisco box >> (can't believe it) >> >> The background is: we're using ISIS as IGP, and >> utilized level-1/2 link. >> >> thanks for any input. >> >> regards, >> >> Yu Ning >> ------------------------------------------- >> (Mr.) Yu(2) Ning(2) >> ChinaNet Backbone Operation >> Networking Dep.,Datacom Bureau >> China Telecom.,Beijing(100088),P.R.C >> +86-10-66418121/66418122/66418123(fax) >> ------------------------------------------- >> >> >> > > >===== > >-- >D.U.M.B.K.I.D. > >__________________________________________________ >Do You Yahoo!? >Send instant messages & get email alerts with Yahoo! Messenger. >http://im.yahoo.com/ > |