回复: Strange result while ping serial interface

["Yu Ning" <yuning () cndata com>]

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 <dumbkid0 () yahoo com>
To: Yu Ning <yuning () cndata com>; nanog-post <nanog () merit edu>
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 <yuning () cndata com> 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.
>
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