From: Chua, Parry (Parry.Chua@xxxxxxxxxx)
Date: Mon Apr 22 2002 - 02:15:58 GMT-3
Let me just break it down to a small piece, just two routers R3 and R8 with igr
p only....
Major network 172.30.0.0 = a.b.x.y
===================================
lo a.b.83.8/24-(R8)-e0[a.b.30.8/24]-[a.b.30.3/24]-e0/0-[R3]-lo33 a.b.33.1/25
-lo34 a.b.33.129/25
a.b.30.129/25 secondary address at e0 of R3
You will see that at R8 , I can ping to a.b.33.1 or a.b.33.129
----------------------------------------------------------------
version 12.0
!
hostname R3
!
ip subnet-zero
no ip domain-lookup
!
!
interface Loopback33
ip address 172.30.33.1 255.255.255.128
no ip directed-broadcast
!
interface Loopback34
ip address 172.30.33.129 255.255.255.128
no ip directed-broadcast
!
interface Ethernet0/0
ip address 172.30.30.1 255.255.255.128 secondary
ip address 172.30.30.3 255.255.255.0
no ip directed-broadcast
no ip split-horizon
!
!
router igrp 30
timers basic 9 9 27 28 56
passive-interface default
no passive-interface Ethernet0/0
network 172.30.0.0
distribute-list block out Ethernet0/0
!
ip classless
!
!
ip access-list standard block
deny 172.30.80.0 0.0.0.255
permit any
!
end
/////////
R3#s ip route
172.30.0.0/16 is variably subnetted, 6 subnets, 2 masks
C 172.30.33.128/25 is directly connected, Loopback34
C 172.30.33.0/25 is directly connected, Loopback33
C 172.30.30.0/25 is directly connected, Ethernet0/0
C 172.30.30.0/24 is directly connected, Ethernet0/0
C 172.30.3.0/24 is directly connected, Loopback0
I 172.30.83.0/25 [100/1600] via 172.30.30.8, 00:00:06, Ethernet0/0
//////////
R3#
17:40:15: IGRP: received update from 172.30.30.8 on Ethernet0/0
17:40:15: subnet 172.30.83.0, metric 1600 (neighbor 501)
R3#
17:40:20: IGRP: sending update to 255.255.255.255 via Ethernet0/0 (172.30.30.3)
17:40:20: subnet 172.30.30.0, metric=1100
17:40:20: subnet 172.30.3.0, metric=501
17:40:20: IGRP: sending update to 255.255.255.255 via Ethernet0/0 (172.30.30.1)
17:40:20: subnet 172.30.33.128, metric=501
17:40:20: subnet 172.30.33.0, metric=501
17:40:20: subnet 172.30.30.0, metric=1100
17:40:20: subnet 172.30.83.0, metric=1600
R3#
17:40:24: IGRP: received update from 172.30.30.8 on Ethernet0/0
17:40:24: subnet 172.30.83.0, metric 1600 (neighbor 501)
R3#
17:40:29: IGRP: sending update to 255.255.255.255 via Ethernet0/0 (172.30.30.3)
17:40:29: subnet 172.30.30.0, metric=1100
17:40:29: subnet 172.30.3.0, metric=501
17:40:29: IGRP: sending update to 255.255.255.255 via Ethernet0/0 (172.30.30.1)
17:40:29: subnet 172.30.33.128, metric=501
17:40:29: subnet 172.30.33.0, metric=501
17:40:29: subnet 172.30.30.0, metric=1100
17:40:29: subnet 172.30.83.0, metric=1600
R3#
////////////////////////////////
!
version 12.0
!
hostname R8
!
ip subnet-zero
no ip domain-lookup
!
!
interface Loopback83
ip address 172.30.83.8 255.255.255.0
no ip directed-broadcast
!
interface Ethernet0
ip address 172.30.30.8 255.255.255.0
no ip directed-broadcast
!
!
router igrp 30
timers basic 9 9 27 28 56
network 172.30.0.0
!
ip classless
!
end
/////
R8#s ip route
172.30.0.0/16 is variably subnetted, 5 subnets, 2 masks
I 172.30.33.128/32 [100/1600] via 172.30.30.1, 00:00:02, Ethernet0
I 172.30.33.0/24 [100/1600] via 172.30.30.1, 00:00:02, Ethernet0
C 172.30.30.0/24 is directly connected, Ethernet0
I 172.30.3.0/24 [100/1600] via 172.30.30.3, 00:00:02, Ethernet0
C 172.30.83.0/24 is directly connected, Loopback83
///////////
R8#
R8#
R8#ping 172.30.33.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.30.33.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
R8#ping 172.30.33.129
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.30.33.129, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
R8#
====================
> Parry Chua
> COMPAQ Computer Asia Pte Ltd
> Customer Services - APD
> Tel : +65-395-1856
> Fax : +65-3951878
> Email : parry.chua@compaq.com
>
>
/////////////////////////////////
-----Original Message-----
From: Chua, Parry
Sent: Monday, April 22, 2002 9:41 AM
To: 'hong tony'; Lupi, Guy; ying chang; nigel_taylor@hotmail.com;
ccielab@groupstudy.com
Subject: RE: FLSM has longer mask than VLSM Probl.
Hello Tony,
Your R8 has two interface with /25 and one interface /24, and you rung igrp he
re, right ?
The next hop router R6 also run igrp with /24 to R8, right ?
In this case, you can setup secondary ip address at R8 s0 wich gas a /24 subnet
, the ideal here is to send the two /25 as one /24 to next hop, setup secondary
ip address at s0 said 172.16.86.1/25,
or 172.16.86.129/25, you may has to disable sp at this interface and then do fi
ltering to act as sp is on. So you should able to send 172.16.80.0 from R8 to R
6 and appear as 172.16.80.0/24.
Try it out..
> Parry Chua
>
>
///////////////
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:58:15 GMT-3