It doesn't look like anyone responded, so I'll take a crack at it..... At 02:08 AM 1/24/02, Matsuzaki Kei wrote: >Hi all, > >This is my first posting. >I have two questions that I would like you guys to answer. > >First question: > > I'm connecting two Cisco 2621 by using Serial cable, and I'm > configuring these two routers. > > However, when I reload one router, the other also suddenly reload > itself automatically at the same time.
The other router shouldn't reload. Are you sure it had completed loading and was in a stable state? Perhaps it was in the middle of SLARPing from the router that you reloaded. There are some gotchas in lab networks with routers connected back-to-back via a serial cable. When you load a router, if the other router is already running, the new router will try to determine its IP address based on the running router's IP address. (This is called SLARP). The new router will then try to get its config from a TFTP server. This can take a long time and be irritating. It can appear that the router has hung. The new router will add the "service config" command into its saved config. You will want to remove this with the "no service config" command. Otherwise the router will have this annoying behavior every time it boots. To avoid problems, disconnect the serial cable until you have everything configured the way you want. Then connect the cable. >Second question: > > I'm connecting three Cisco 2621 by using Serial cable like a > triangle, and I have assigned the same network addresses from > 192.168.1.0/24 ON PURPOSE. I have not set any routing protocol > and any static route. If the router ports are in the same network, then you are right, you won't need a routing protocol or static routes. > e.g. Router1 s0/0=192.168.1.1/24 s0/1=192.168.1.2/24 > Router2 s0/1=192.168.1.3/24 s0/1=192.168.1.4/24 > Router3 s0/0=192.168.1.5/24 s0/1=192.168.1.6/24 > > (Router1)-------(Router2) > \ / > \ / > \ / > \ / > \ / > (Router3) Your core network in this case is a Layer-2 WAN. This is a little strange, but should work. There are actually some real-world networks that do this. > As far as I know, the cable which is connected to a router is > the network itself. If I do the same thing by using ethernet, > the error message 'IP address is overlapping' will be shown. If you put multiple Ethernets into one Layer-2 network, you're doing bridging or switching, not routing. To get this to work on the router you would have to configure bridging. A bridge doesn't need IP addresses, though it's nice if a bridge has one address for management. But you would give it just one IP address, not two. Cisco doesn't expect you to configure two Ethernet ports on a router in the same network, so the software complains when you do it. Cisco seems to have anticipated the need to do this on serial links, and so the software doesn't complain. Priscilla > However, in this case, no message was shown and I could set > the same network address above, and I could ping all three > routers. I have no clue why I could ping without assigning > the different network address and without routing. > > sorry for this long statement. > I really appreciate your reading my questions. > > Thank you, > > Kei ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=33143&t=33049 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
