Paul Williamson wrote: > > Think i figured it out > The router will forward the subnet broadcast regardless of > whether the no ip > directed-broadcast command is configured on the ingress/egress > interface or > not - IF the destination subnet isn't locally attached to the > router.
That makes sense. The router can't know for sure if a packet for a non-local destination even is a broadcast. It may not know the prefix boundary (subnet mask) for non-local networks. It just knows this for its own interfaces (because it's configured on its own interfaces). > Guess the router just does a route lookup and forwards it > > If the destination network is directly attached and ip forward > directed-broadcasts is disabled then the router replys on > behalf of the > subnet but does not forward the broadcast out onto the subnet > > The replies i was seeing were from subnets that were locally > attached to non > cisco firewalls Ah. That explains it. Thanks for letting us know. Whew. I didn't have much hope for this thread! I'm glad it worked out. :-) Priscilla > > Thanks for your help > > -----Original Message----- > From: Priscilla Oppenheimer > To: [EMAIL PROTECTED] > Date: Thursday, November 21, 2002 6:36 PM > Subject: Re: Router forwarding directed broadcasts [7:57780] > > > >[EMAIL PROTECTED] wrote: > >> > >> I'm sure they will, but my routers still forwarding subnet > >> broadcasts > >> even with this line in a sh ip int output:- > >> Directed broadcast forwarding is disabled > > > >Why don't you send us a config and some discussion of the > situation and > your > >methods of testing. > > > >This group can be helpful, despite the numerous silly answers, > but we can't > >output a solution to your problem with no useful input. > Troublehsooting > >requires data. If you can give us data, perhaps we can help > you. The end > >result could be that everyone benefits. > > > >Also, please use a meaningful title on your messages. Thanks > > > >_______________________________ > > > >Priscilla Oppenheimer > >www.troubleshootingnetworks.com > >www.priscilla.com > > > >> > >> Thanks > >> -P > >> > >> > 5 games of cricket Between Australia and England have just > >> commenced... > >> > Australia won the first game very convincingly > >> > > >> > Australia should go a clean sweep > >> > > >> > -- > >> > Regards, > >> > > >> > Peter Kingston > >> > Telstra BigPond Direct > >> > Freecall 1800 066 594 > >> > ""Priscilla Oppenheimer"" wrote in message > >> > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >> > > Well you better explain this to us Yankees. Our baseball > >> season is over > >> > > unfortunatley, and now all we have is football (ugh). > Well > >> we have hockey > >> > > and basketball too, I guess, and they're a litte better! > :-) > >> > > > >> > > Priscilla > >> > > > >> > > Peter Kingston wrote: > >> > > > > >> > > > I just as a little bit of friendly rivalry, > >> > > > > >> > > > I believe there is more than yourself confused in > London, > >> > > > naming your > >> > > > cricketers.... 5 zips looks like a fair chance > >> > > > > >> > > > -- > >> > > > Regards, > >> > > > > >> > > > Peter Kingston > >> > > > Telstra BigPond Direct > >> > > > Freecall 1800 066 594 > >> > > > wrote in message > >> > > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >> > > > > Someone asked me a question which confused me:- > >> > > > > If i ping a network broadcast from a host on a > different > >> > > > network, which > >> > > > > passes through a cisco router why do i get replies > from > >> > > > certain devices. > >> > > > > > >> > > > > The router has directed broadcast forwarding > disabled. > >> > > > > I thought the router would therefore drop the packet > >> > > > > > >> > > > > Any thoughts > >> > > > > Thanks > >> > > > > -P > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57860&t=57780 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
