I am using the Cisco 5 router configuration to teach 1st year classes as in Cisco Networking Academy program.I faced a strange problem whose cause I am unable to fathom.After the routers are set up I can ping from any router to any router.
However from a desktop connected to a switch connected to Router A ethernet interface I can ping Router B interfaces but no further.One local feedback was that this is a switch problem but then it doesn't explain why I can ping Router B.I was wondering if there is any known problem with Windows Ping?One thing I observed was that both RIP and IGRP were enabled in Router A.
Any clues? I have no way to reproduce the problem as due to time constraints I couldn't save the router configurations.
This sounds like possibly your Ethernet (the one your desktop was connected to) network might not have been advertised to the rest of the routers properly. Your any to any pinging from router to router may have not included reachability to this network and may have looked like you had full reachability when you actually did not. This would have allowed your PC to ping a directly connected (routerB) device bu no further due to other routers having no knowledge of this source network. Just an idea. RIP and IGRP on Router_A should have caused no problems if configured correctly (redistribution,etc). I don't see the switch problem here. Hope this helps,
The router B was not directly connected.The PC was connected to a switch port .Another switch port was connected to ethernet port of Router A.Router A
serial port(DCE) was connected to Router B serial port(DTE).I could ping from
PC to router B but no further.
As you say,what could be the reason for the ethernet network not being advertised properly.
Without seeing your configurations there may have been many reasons for this network not to be advertised. Since you stated that RIP and IGRP were running, possibly the classful network was different on your ethernet and not contained within the network statements in the routing protocols. Distribution not setup properly, etc. Just guessing.
I was assuming you were pinging Router_B's Serial. This would be connected (to Router_A).. So pings would succeed to this interface. Pings beyond this interface would not succeed if this network was no advertised. If I am wrong with my assumption of where you are pinging (router_b's Serial) then it must be something else.
Hope this helps,
Router_B was directly connected, l believe, to Router_A. This is the direct connection I was referring to. Forgot to put that in my last post.
The configuration is:
Desktop PC running Windows 98
a)Desktop NIC connected by cat-5 straight through cable to switch A
b)Hyperterminal running on Desktop connected through console cable to Router A console port
c)Switch A connected to Router A ethernet port through AUI
d)Desktop IP address falls in the ethernet network address range of Router A
e)Desktop Gateway is set to IP address of ethernet interface of Router A
Router A serial 0 port(DCE) connected to Router B serial 1 port(DTE)
Router B serial 1 port(DCE) connected to Router C serial 0 port(DTE)
Router C serial 1 port(DCE) connected to Router D serial 0 port(DTE)
Router D serial 1 port(DCE) connected to Router E serial 0 port(DTE)
From Desktop Hyperterminal it is possible to ping all interfaces of all routers(
all serial interfaces,all ethernet interfaces).
From Command Prompt Window in Desktop it is possible to ping all Router A
interfaces(serial and ethernet) and all Router B interfaces(serial and ethernet)
.However all other router interfaces are inaccessible.
Same result with telnet and tracert
Although your suggestions make sense I am still confused about the problem
and guess I just have to try and reproduce the scenario again.
dear just check show arp on all the rtr?on each rtr it should show the entry of all rtr. or u can check the switch table. it is pinging to rtr A and B bcos it has an entry in switch table for rtr A and rtr B is direclty connected to rtr A. but other rtr r not directly connected to rtr A.just define g/w of last resort on each rtr ..i think this may solve ur problem.
do check arp entries on each rtr.
As others have stated here, this sounds to me like a routing issue as opposed to a switching issue. Someone already gave some good advice here .... if you can re-create the configs, check the routing tables. I think you might find that router B just simply does not know how to get to the destination address and may just need a gateway of last resort to route the packets thru. Personally, I'd start with that and then possibly move the the other router configurations.
I've gone through all the comments made by the other people for your problem. Is there anyway that you can provide the configuration of the routers and also "show ip route" on all routers? I think that the problem is associated with using RIP and IGRP since these two are classfull routing protocols.