| T.R | Title | User | Personal Name
 | Date | Lines | 
|---|
| 751.1 |  | MARVIN::TURNER | Neil Turner IPEG REO, 830-4140 | Thu Feb 13 1997 04:48 | 24 | 
|  | I  assume  from your descriptions that each branch site has a single PVC 
to its regional site. In addition to it's PVC to the branch  a  regional 
site  then has a single PVC back to the central site. I also assume that 
there is no requirement of communication  between  branches  or  between 
regional sites. All traffic is to be from branch to region and region to 
central site?
If  the  above is true then you should configure the central to regional 
sites into one IP subnet and each regional site to  its  branches  in  a 
second  IP  subnet.  However  in order that the RIP information from the 
branch sites is propagated to the central site the Frame Relay interface 
on  the  regional  site  routers should be configured to have BOTH subnet 
addresses (ie that of the branches and that of the central site).
If any inter-branch or inter-regional  communication  is  required  then 
you will have to add static routes for these paths.
Incidentally  have  you  considered  using  PPP  over frame relay of this 
configuration? PPP over frame  relay  treats  each  PVC  as  a  separate 
point-to-point  link  and may provide a better solution particularly if 
inter-branch or inter-region traffic is required. It also allows you  to 
use data compression over the PVCs (depending on speed).
Neil
 | 
| 751.2 | FR meshed network and PPP over FR? | SNOFS1::63496::CHIUANDREW |  | Wed Feb 19 1997 19:59 | 12 | 
|  |     re .1
    
    It seems to me that if it is a MESHED network then we can 'group' ALL
    the FR interfaces into one IP subnet. If it is a POINT-TO-POINT and
    there will be inter-branches and inter-region communications, then we
    have to set up PPP over fram relay where each sub-interface (within
    the same FR physical line) will be one DIFFERENT IP subnets, is it
    correct?
    
    
    thanks in advance for help!
    Andrew Chiu - NSIS Sydney
 | 
| 751.3 | Meshed or Fully meshed... | MARVIN::TURNER | Neil Turner IPEG REO, 830-4140 | Thu Feb 20 1997 02:53 | 7 | 
|  | Yes if the configuration is FULLY meshed (every site has a PVC between itself and
every other remote site) then it would be possible to use just one IP subnet for
all of the FR interfaces on the routers. But I think this is unlikely in a
configuration this large (it would be very costly). If it is not FULLY meshed
then you need to follow my suggestions in .-2 and use 2 different subnets.
Neil
 | 
| 751.4 |  | MARVIN::CLEVELAND |  | Thu Feb 20 1997 05:32 | 3 | 
|  |     If you do use PPP over FR to arrange things on a point-point basis, you
    don't need to assign a subnet to each PPP circuit--just use unnumbered
    links.
 | 
| 751.5 | OSPF w/ P-to-MP interfaces | MARVIN::HART | Tony Hart, InterNetworking Prod. Eng. Group | Fri Feb 21 1997 03:03 | 8 | 
|  | An alternative is to run OSPF rather than RIP and use point-to-multipoint
interfaces.  Unlike NBMA mode, P-to-MP doesn't require the FR network to be
fully meshed, and you can use whatever addresses you like on the FR interfaces.
Thats just a FYI, the previous notes have suggested other good reasons why you
might want to run PPP anyway (compression for instance).
Tony
 | 
| 751.6 | How to do this? | SNOFS1::KHOOJEANNIE | Hangovers: The Wrath of Grapes? | Tue Feb 25 1997 20:07 | 12 | 
|  |     Our customer has 4 regional offices which are linked to their head office
    with a PVC each.  All the WAN frame relay interfaces are in the same IP
    subnet.
    
    What are the various options to enable one regional office to
    communicate with another regional office?  In Cisco routers, I believe
    it is something to do with turning off split horizon - how does it work
    with the RouteAbout?
    
    Regards
    Jeannie
    
 |