On Tue, 5 Dec 2000, Mohamed Heeba wrote:
> i believe that i shouldnt use different masks on Ripv1 router , i was trying
> to check if the mask will be changed on the other end of the connection
> (which is right :)) , although now this doesnt have any meaning since the
> serial link should aslo have the same mask of the ethernet subnet of the
> source router (which will force me to make consistant mask for the entire
> network to make everything work fine )
>
>
> i dont think split horizon has anything here ...hasnt it ??
your right. What I was thinking (without reading) was that sometimes when
using VLSM, you'll create a situation where you have overlapping subnets,
and that can lead to a problem where a router won't accept the update
because it thinks it already is announcing that same route..........I was
to quick with the reply
brian
>
> thx for the help
> > -----Original Message-----
> > From: Brian [SMTP:[EMAIL PROTECTED]]
> > Sent: Monday, December 04, 2000 3:50 PM
> > To: Mohamed Heeba
> > Cc: '[EMAIL PROTECTED]'
> > Subject: Re: Rip problem , suppressing null update!
> >
> > On Mon, 4 Dec 2000, Mohamed Heeba wrote:
> >
> > > guys !
> > > i have two routers connected through their serial , im configuring rip
> > on
> > > them
> > >
> > > R1 e0 ip add is 172.16.1.1/27
> > > ser 0 ip add is 172.16.1.33/28
> > >
> > > R2 e0 ip add is 172.16.1.49/29
> > > ser 0 ip add is 172.16.1.34/28
> > >
> > > there is no rip updates between the two routers ..im getting only
> > > "suppressing null updates "
> >
> > are you using rip v1? you need to use something that understands VLSM.
> > Otherwise split horizon will get you in the above case.
> >
> > >
> > > also when i change the mask of ser0 on R1 to /27 , the updates pass
> > normally
> > > and take the mask of the
> > > /28 on the other end
> >
> > yes they use the mask of the interface they have that subnet on..........
> >
> > >
> > > my question is
> > > Does this mean that if the mask is inconsistent on RIP router , it will
> > not
> > > send updates ?????
> >
> > you can't use inconsistant masks for a network running a FLSM protocol
> > like RIPv1. You have to either use like masks, or use a VLSM capible
> > protocol.
> >
> > > this means when R1 mask is consistent (/27) for both interfaces , the R1
> > > will send updates but it will not receive anything because R2 masks are
> > not
> > > consistent ??
> > >
> >
> > brian
> >
> > >
> > > somebody to confirm please !!!!!
> > >
> > > _________________________________
> > > FAQ, list archives, and subscription info:
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> > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
> > >
> >
> > -----------------------------------------------
> > Brian Feeny, CCNP+ATM, CCDP [EMAIL PROTECTED]
> > Network Administrator
> > ShreveNet Inc. (ASN 11881)
>
-----------------------------------------------
Brian Feeny, CCNP+ATM, CCDP [EMAIL PROTECTED]
Network Administrator
ShreveNet Inc. (ASN 11881)
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