keepalive setting and ping command

[preeda]

Dear all,

I have two routers, A and B connected running HDLC protocol. The problem is that from router A I can not ping router B, eventhrough interface and line protocol up at sh int command.There is no ACL setting to both routers.

I was told by carrier to enable keepalive at router A Later the problem is gone. Anyone has any idea to this ??

Well, I have tried to put no keepalive back to router A, and the problem comes back again. I have no idea how this related. Please help !!

Thanks,
Preeda

 

[routerman]

Is your link A to B using IP unnumbered?

If so then which on interface did you enable keep alive?

All the `no keepalive' command does on an ethernet interface is force the interface to the upstate regardless of the real state. On a serial interface it depends on the line protocol etc.

 

[preeda]

We don't have ip unnumbered. The interface that I am talking about is serial 0. In this case, the line protocol still up, but can not ping the remote router not until enable keepalive. Again we are running HDLC between these 2 routers.

Thanks,
Preeda