From: Ouellette, Tim (tim.ouellette@xxxxxxx)
Date: Wed Jul 31 2002 - 00:28:46 GMT-3
r6 was generating the route to 24.0.0.0/8 fine but as soon as I configured
the "ip broadcast-adress 172.16.56.1" then as you can see in the original
message, the route stopped getting learnt and was about to timeout.
What I was thinking would happen is that R6 instead of sending a broadcast
to 255.255.255.255 for r5 to hear, that I would be able to send a "direct
broadcast" right to 172.16.56.1 (e0 address of r5) and then it would process
it and understand it.
Anyone?
Tim
-----Original Message-----
From: Ouellette, Tim [mailto:tim.ouellette@eds.com]
Sent: Tuesday, July 30, 2002 10:07 PM
To: 'ccielab@groupstudy.com'
Subject: RIP Broadcast issues and NBMA stuff. ? directed-broadcast?
Team,
after reading some interesting documents on Cisco. I "discovered" the "ip
broadcast-address" command. I instantly though of "NBMA broadcast issues".
I thought this command would be usefull. I did use plain ethernet in the
following scenario just to test but I would think it would work in other
scenarions.
Here's the scenarion. R5 has some other network "hanging" off it,
including 192.168.1.0/24, 10.1.1.0/24 and R6 has 24.0.0.0/8 off of it.
Rather than have r6 broadcast to 255.255.255.255 on the ethernet segment, I
issued a "ip broadcast-address 172.16.51.1" which is more of a unicast type
packet but I figured that the R5 would take this update without a problem.
R5 (.1)----------172.16.56.0/30 --------------(.2) R6
r6(config)#int e0
r6(config-if)#ip broadcast-address 172.16.56.1 ?
<cr>
r6(config-if)#ip broadcast-address 172.16.56.1
r6#
%SYS-5-CONFIG_I: Configured from console by consolesh ip int e0
Ethernet0 is up, line protocol is up
Internet address is 172.16.56.2/30
Broadcast address is 172.16.56.1
Address determined by setup command
MTU is 1500 bytes
<snip>
r6#
IP: s=172.16.56.2 (local), d=172.16.56.1 (Ethernet0), len 25, sending
broad/mult
icast UDP src=520, dst=520
As you can see, R6 is sending the update to 172.16.56.1 which is the ip
address of the e0 interface of r5.
However, r5 isn't liking the update and the routing table looks like the
following.
r5#r
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter
area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
172.16.0.0/30 is subnetted, 1 subnets
C 172.16.56.0 is directly connected, Ethernet0/0
R 24.0.0.0/8 [120/1] via 172.16.56.2, 00:01:54, Ethernet0/0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, Loopback1
C 192.168.1.0/24 is directly connected, Loopback0
r5#
Does anyone have any ideas?
Tim
This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:36:49 GMT-3