From: Mohammad Saeed (mzsaeed@gmail.com)
Date: Sun Feb 04 2007 - 02:21:52 ART
So, theoratically atleast, a router shall not need to perform routing
betweeb its directly connected networks? Am I right? Because it has
all the entries in the routing table with C (Directly Connected)!!!
And as per my understanding, this how routing process happens, that
router receives the frame, will remove ethernet header, look at the
destnation network address, go and check if he knows how to reach that
network in its routing table, find the entry for that network, prepare
new ethernet frame and send out that interface!!!!!
Regards,
Mohammad Zahed Saeed
On 2/3/07, Scott Morris <swm@emanon.com> wrote:
> The best thing to do here is "debug ip packet" and see what the router tells
> you. Most likely what you will be seeing there is an "encapsulation failed"
> message, which means that something within your configuration is not
> allowing/not returning a Layer2 address for you.
>
> In ethernet world, we have arp that magically does the Layer3 --> Layer2
> resolution for us. Depending on your configuration of serial lines (frame
> relay???) things may need to be manually set.
>
> In any event, the debug will help you get a handle on what the router is
> attempting to do there.
>
> HTH,
>
>
> Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE
> #153, CISSP, et al.
> CCSI/JNCI-M/JNCI-J
> IPexpert VP - Curriculum Development
> IPexpert Sr. Technical Instructor
> smorris@ipexpert.com
> http://www.ipexpert.com
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Mohammad Saeed
> Sent: Saturday, February 03, 2007 11:56 PM
> To: Cisco certification
> Subject: Very basic Routing Question!!!!
>
> Hi,
>
> Sorry, my last email I didn't complete and was sent by mistake....
>
> R1's S0/0 is connected to R5's S0/0.1 and they have network address
> 170.12.23.0/24 with IP Address 170.12.23.1 and 170.12.23.5.
>
> R5 has another S0/0.2 and have IP 173.23.23.5/24. On R1 you give default
> route
>
> ip route 0.0.0.0 0.0.0.0 serial 0/0
>
> Now as R5 has
>
> C 173.12.23.0 connected to S0/0
> C 173.23.23.0 connected to S0/0
>
> in the Routing table and R 1 has defalut route to R5, if you say
>
> R1# ping 173.23.23.5
>
> Why R5 does not respond, when it has the entry for 173.23.23.5 in the
> routing table and R1 is sending the packets with source IP 173.12.23.1????
> Because as I understand, R1 will send the packets for any destination to R5,
> R5 shall look in to its RT that destination is 173.23.23.0, do I know how to
> reach this network, Yes, it is directly connected, so it shall respond, but
> its not, can any bosy explain why?
>
> Regards,
>
> Mohammad Zahed
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Mar 01 2007 - 07:38:45 ART