Khi nao thi khong nen dung "broadcast" trong frame-relay map
Bai nay cua Brian Dennis, vach ro mot truong hop khong nen dung tu khoa broadcast trong frame-relay map
Why send two broadcast packets when you only need to send one?
What if you have 50 spokes, would you map broadcast for each spoke from each spoke? If RIP had 70 networks to advertise, the spoke router needs to send 3 packets to the hub. But if you have the 50 other mappings with the broadcast keyword you would send 150 packets unnecessarily every 30 seconds.
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
Director of CCIE Training and Development - IPexpert, Inc.
Mailto: brian@ipexpert.net
Toll Free: 866.225.8064
Outside U.S. & Canada: 312.321.6924
-----Original Message-----
From: OhioHondo [mailto:ohiohondo@columbus.rr.com]
Sent: Saturday, April 05, 2003 8:33 PM
To: Brian Dennis; 'DougAtHome'; 'ccielab'
Subject: RE: Frame map ip
It processes them and puts the best routes in the IP routing table. Since both of the RIP updates are from the same router, the RIP updates should be the same. I don't see a problem with that. As far as RIP is concerned, it received 2 updates from a neighboring router -- it just didn't wait the full period between updates.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of Brian Dennis
Sent: Saturday, April 05, 2003 9:35 PM
To: 'DougAtHome'; 'ccielab'
Subject: RE: Frame map ip
Let's same we have this config on a spoke router. One mapping to the hub and the other to a second spoke run RIP as the routing protocol.
!
interface Serial1/0
ip address 120.20.234.4 255.255.255.224
encapsulation frame-relay
frame-relay map ip 120.20.234.2 402 broadcast
frame-relay map ip 120.20.234.3 402 broadcast
!
router rip
network 120.0.0.0
!
When RIP has an update to send out the S1/0 interface it sends two of them because of the two mappings with the broadcast keyword. Now when the hub gets the two broadcast packets what does the hub do with them?
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
Director of CCIE Training and Development - IPexpert, Inc.
Mailto: brian@ipexpert.net
Toll Free: 866.225.8064
Outside U.S. & Canada: 312.321.6924
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of DougAtHome
Sent: Saturday, April 05, 2003 3:23 PM
To: ccielab
Subject: Re: Frame map ip
This all surprizes me. Firstly, I would presume that Jeongwoo's configuration would NOT work, and that broadcast is required for these
components. In my labs, after a reboot, the config would definitely
fail
without the broadcast - if not immediately, then definitely after clearing inarp. Secondly, I have never seen samples where spoke to spoke maps eliminated the "broadcast" keyword. My understanding is that the broadcast first allows broadcast messages to be sent across the frame network. Secondly, where necessary, the router emulates broadcast behavior by sending out duplicate messages out all dcli's referenced to that subinterface. I don't know if I will have time to lab this out (my first attempt for the lab is now 3 weeks away), but would be interested in some clarification/explanation. Thanks!
-----Original Message-----
From: Jeongwoo Park [mailto:jpark@wams.com]
Sent: Saturday, April 05, 2003 4:51 PM
To: 'ccielab@groupstudy.com'
Cc: 'Brian Dennis'
Subject: RE: Frame map ip
Thanks a lot for clarifying this.
Now I am converting this;
R2:Hub router
interface Serial0/0.234 multipoint
ip address 120.20.234.2 255.255.255.224
ip ospf network point-to-multipoint
frame-relay map ip 120.20.234.3 203 broadcast
frame-relay map ip 120.20.234.4 204 broadcast
To;
R2
its answer;
interface Serial0/0.234 multipoint
ip address 120.20.234.2 255.255.255.224
ip ospf network point-to-multipoint
frame-relay interface-dlci 203
frame-relay interface-dlci 204
I am not getting different result.
R2#frame map
Serial0/0.234 (up): ip 120.20.234.4 dlci 204(0xCC,0x30C0), dynamic, broadcast,, status defined, active R2#
I get only one map result. Shouldn't I get two of this?
R4:Spoke Router
interface Serial1/0
ip address 120.20.234.4 255.255.255.224
encapsulation frame-relay
ip ospf network point-to-multipoint
frame-relay map ip 120.20.234.2 402 broadcast
frame-relay map ip 120.20.234.3 402 broadcast
R3:Spoke Router
interface Serial1/0.234 point-to-point
ip address 120.20.234.3 255.255.255.224
ip ospf hello-interval 30
frame-relay interface-dlci 302
-----Original Message-----
From: Brian Dennis [mailto:brian@labforge.com]
Sent: Saturday, April 05, 2003 12:36 PM
To: 'Jeongwoo Park'; ccielab@groupstudy.com
Subject: RE: Frame map ip
Maybe there was a requirement to enable the router to ping itself.
As a side note the broadcast keyword isn't needed and is actually causing duplicate broadcast packets to be sent to "120.20.234.3". When spokes map to other spokes the broadcast keyword is useless because to hub will absorb the broadcast.
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
Director of CCIE Training and Development - IPexpert, Inc.
Mailto: brian@ipexpert.net
Toll Free: 866.225.8064
Outside U.S. & Canada: 312.321.6924
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Jeongwoo Park
Sent: Saturday, April 05, 2003 11:48 AM
To: 'ccielab@groupstudy.com'
Subject: Frame map ip
Hi all.
I am doing ccie practice lab scinerio. I found a interesting answer about frame relay map.
its answer;
interface Serial0/0.234 multipoint
ip address 120.20.234.2 255.255.255.224
ip ospf network point-to-multipoint
frame-relay map ip 120.20.234.2 203 broadcast
frame-relay map ip 120.20.234.3 203 broadcast
frame-relay map ip 120.20.234.4 204 broadcast
As you can see, why would you want to have map frame to your own interface ip address? Can anyone of you explain this?
Thanks a lot,
JP
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