Hi , Thanx both of u for answering But my design is like that I am using point to point subinterfaces for connecting to remote sites.right now only static routing we have but it might be tommorow we may switch for dynamic routing protocols so in that case as both of us sain no need of broadcast keyword on point to point subinterfaces. if its not needed then why in the command there is option for broadcast keyword.
Example: Int serial 0/0 no ip address int serial 0/0.1 ip address 1.1.1.1 ?255.255.255.0 frame-relay interface-dlci 16 broadcast should i give broadcast or not ,Correct this is point to point link and adjancies will be established automatically. why this broadcast option is there ,still a confusion although this keyword is optional.This maeans this keyword will never be used on point to point interfaces. am i right if not please correct me Priscilla Oppenheimer wrote: > > Priscilla Oppenheimer wrote: > > > > Simmi Singla wrote: > > > > > > Hi all, > > > Can anybody explain me when i use the broadcast keyword in > sub > > > interface(fram-relay interface-dlci 16 broadcast) then if i > > > have only static routing will it affect that.I read that it > is > > > used only for OSPF to pass broadcasts , if multicasting > > > disabled.But In a scenario if I have no dynamic routing and > > > give this command what will happen. > > > will it pass unknown broadcasts on frame-relay. > > > > Remember a router doesn't pass broadcasts, i.e. forward > > broadcasts. So think about when you would need to let a router > > send broadcasts on its own, from its own interface. The usual > > case is to support dynamic routing. If you are using static > > routing, then you don't have to worry about it. > > > > Frame Relay is used on routers to create virtual circuits to > > remote sites. A point-to-point virtual circuit can send > > broadcasts without any problem. > > > > Frame Relay is often designed in a hub-and-spoke topology, > > however, with the hub router connecting many remote sites. A > > typical design is to place all the WAN serial interfaces in > > this design in the same subnet, thus creating a multiaccess > WAN > > "cloud." The cloud resembles a LAN subnet, but does not > support > > broadcasting like a LAN would. The cloud is a nonbroadcast > > multiaccess (NBMA) network. > > > > When a router sends a broadcast into the cloud, only a > directly > > connected router on the same virtual circuit hears it. Many > > protocols were designed with the assumption that two hosts on > > the same subnet have Layer 2 connectivity and can easily hear > > each other's broadcasts. This isn't the case in a Frame Relay > > hub-and-spoke topology. > > > > So to fix the problem, if this is your design, you better add > > the "broadcast" keyword if you are using dynamic addressing. > > I meant to say "dynamic routing" there. That is, use the > broadcast keyword if you need the router to send routing > protocol route updates or hellos as broadcasts (or multicasts). > He had asked about static routing, so I wanted to add that > thought but then the darn phone rang while I was typing and I > wrote dynamic addressing instead of dynamic routing. :-) > > Priscilla > > > > For example, use seomthing like "frame-relay map protocol > > address broadcast." > > > > The other solution, however, is to use subinterfaces. This > > turns the links back into normal point-to-point links. Then > > they support broadcast no problem. > > > > Chuck can correct me if I got this wrong! :-) > > > > Priscilla > > > > > moreover exactly how it is used in point-to-point sub > > > interfaces. > > > Thanx a lot in advance--:) > > > > > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=61877&t=61829 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
