From: Peter (peter@cyscoexpert.com)
Date: Sun Feb 16 2003 - 12:56:07 GMT-3
The reason you are able to ping the other spoke is because the routing
tables on spokes have /32 OSPF routes installed for other spokes. So if you
had a hub and 100 spokes on the same multipoint subnet over Frame you would
see all /32 routes for all spokes. And all happens because of OSPF network
type you chose - point-to-multipoint. If you change it to NBMA or broadcast
it won't work anymore.
_____________________________
Peter
#7247 (R&S, Security)
CyscoExpert Corp.
4433 W. Touhy Ave. Suite 410
Lincolnwood, IL 60712
Phone (847) 674-3392
Toll Free (866) CyscoXP (297-2697)
Fax (847) 674-2625
----- Original Message -----
From: "Hunt Lee" <ciscoforme3@yahoo.com.au>
To: <ccielab@groupstudy.com>
Sent: Sunday, February 16, 2003 6:53 AM
Subject: Frame-relay mystery
> Hi friends,
>
> I have a little confusion in a very simple FR setup (hub & spoke
topology)... all 3
> are in OSPF (not that I think it would have any affect on this ;)
>
> R3 R5
> \ /
> R1
>
> IP Addressing:
>
> R1 - 137.20.101.1/24
> R3 - 137.20.101.3/24
> R5 - 137.20.101.5/24
>
>
> I don't understand that even if each of my spoke ONLY has a frame-relay
map ip
> statement pointing to the hub (R1), that they somehow can still managed to
ping each
> other!!!
>
> On R1 (hub)
>
> R1#sh run
> Building configuration...
>
> Current configuration : 1868 bytes
> !
> interface Serial0/0
> no ip address
> encapsulation frame-relay
> no ip mroute-cache
> no fair-queue
> !
> interface Serial0/0.1 multipoint
> ip address 137.20.101.1 255.255.255.0
> ip access-group blockR6 in
> ip ospf network point-to-multipoint
> frame-relay map ip 137.20.101.3 103 broadcast
> frame-relay map ip 137.20.101.5 105 broadcast
> no frame-relay inverse-arp
> !
> end
>
> On R3 (spoke)
>
> interface Serial0
> ip address 137.20.101.3 255.255.255.0
> encapsulation frame-relay
> ip ospf network point-to-multipoint
> no ip mroute-cache
> frame-relay map ip 137.20.101.1 301 broadcast
> no frame-relay inverse-arp
> bridge-group 1
> end
>
> On R5 (other spoke)
>
> R5#sh run
> Building configuration...
>
> !
> interface Serial0
> ip address 137.20.101.5 255.255.255.0
> encapsulation frame-relay
> ip ospf network point-to-multipoint
> no fair-queue
> clockrate 64000
> frame-relay map ip 137.20.101.1 501 broadcast
> no frame-relay inverse-arp
> !
> end
>
> R3#ping 137.20.101.5
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 137.20.101.5, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 116/118/128 ms
> R3#
>
> R5#ping 137.20.101.3
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 137.20.101.3, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 116/138/220 ms
> R5#
>
> Yet, I was expecting that the spoke, without the additional frame-relay
map ip
> statement pointing with each other, should not be able to ping each
other... (apart
> from able to ping the hub).
>
> Anyone has any clue on this?
>
> Regards,
> L.
>
>
> http://mobile.yahoo.com.au - Yahoo! Mobile
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phone.
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2003 - 11:06:25 GMT-3