From: Ajit (ajitmohanraj@hathway.com)
Date: Fri Aug 01 2003 - 18:16:37 GMT-3
I can think of a Frame Relay env, wherein using an interface only bound
static route will cause problems :
Eg:
int s0
ip add 10.1.1.1 255.255.255.0
encap frame
frame-relay map ip 10.1.1.2 102
frame-relay map ip 10.1.1.3 103 ...etc
...........
............
!! and now I have a static route in the config saying
ip route 10.1.2.0 255.255.255.0 serial 0
ip route 10.1.3.0 255.255.255.0 serial 0
now the problem is that I will not be able to ping the hosts (10.1.1.2 and
10.1.1.3 etc) because the map table contains no entry for a give next-hop
address ...and hence the router drops the packet and sends an ICMP back ....
Meaning to say, suppose this router receives a packet 10.1.3.20 to be
routed, the router will look up the routing table and find the 2nd static
route matching it ..which definately states that serial 0 is the interface
through which it has to leave. But what about the next-hop address ? Since
we havent supplied one in the static route statement, the router uses the
destination address in the ip packet (which is 10.1.3.20) to find the map
statement that would correspond to the DLCI to be used . Now since there is
no map entry for this, the packet is dropped by the router !!
I hope this helps !!
to rectify this, change the static route to include the address of the
next-hop specifically
ip route 10.1.2.0 255.255.255.0 serial 0 10.1.1.2
----- Original Message -----
From: "Tony Schaffran" <groupstudy@cconlinelabs.com>
To: "'Ajit'" <ajitmohanraj@hathway.com>; "'Oliver Ziltener'"
<ziltener@netcloud.ch>; <ccielab@groupstudy.com>
Sent: Saturday, August 02, 2003 1:12 AM
Subject: RE: ip route 0.0.0.0 0.0.0.0 fastethernet0/0 192.168.100.1
> I think he was asking, why would you use the interface and an IP address
in
> the static route? Not, why would you use a static route?
>
>
>
> Tony Schaffran
> Network Analyst
> CCIE #11071
> CCNP, CCNA, CCDA
> NNCDS, NNCSS, CNE, MCSE
>
> http://www.cconlinelabs.com/
> Your #1 choice for online cisco rack rentals.
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Ajit
> Sent: Friday, August 01, 2003 12:39 PM
> To: Oliver Ziltener; ccielab@groupstudy.com
> Cc: Oliver Ziltener
> Subject: Re: ip route 0.0.0.0 0.0.0.0 fastethernet0/0 192.168.100.1
>
> the ip route 0.0.0.0 0.0.0.0 fastethernet0/0 192.168.100.1one is preferred
> because you are specifying the next hop address ..will reduce ARPing
> (because when you dont specify the next hop address, the router has to use
> the destination ip address in the packet and ARP out to get the next hop
> address.
>
> So when yu supply this in the static route, you actually save that ARPing
> process.
>
> hope that helps !!
> ----- Original Message -----
> From: "Oliver Ziltener" <ziltener@netcloud.ch>
> To: <ccielab@groupstudy.com>
> Cc: "Oliver Ziltener" <ziltener@netcloud.ch>
> Sent: Friday, August 01, 2003 11:56 PM
> Subject: Q: ip route 0.0.0.0 0.0.0.0 fastethernet0/0 192.168.100.1
>
>
> > I think everybody knows the diffenence between the both lines
> > ip route 0.0.0.0 0.0.0.0 fastethernet0/0
> >
> > ip route 0.0.0.0 0.0.0.0 192.168.100.1
> >
> > but both together ip route 0.0.0.0 0.0.0.0 fastethernet0/0
192.168.100.1?
> > I which situation is a need for this?
> >
> > Oliver
> >
> >
> > _______________________________________________________________________
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