From: Harish DV/peakxv (harish.dv@xxxxxxxxxx)
Date: Sat Jun 29 2002 - 17:55:14 GMT-3
Ahmed,
There is no difference between the 2 methods. However, defining the
wildcard bits with the whole subnet (ex. 0.0.0.255) will be usefull in some
cases.
Lets take an example:
Assume Router R 1 has 3 interfaces under ospf.
Int 1 is in ospf area 0 (ip add 172.16.1.1/24)
Int 2 and 3 are in ospf area 1 (ip add 172.16.2.1/24 and 172.16.3.1/24
respectively)
Now under ospf: - there are 2 ways of configuring this
1st method
router ospf <pro id>
network 172.16.1.1 0.0.0.0 area 0
network 172.16.2.1 0.0.0.0 area 1
network 172.16.3.1 0.0.0.0 area 1
2nd method
router ospf <pro id>
network 172.16.1.1 0.0.0.0 area 0
network 172.16.0.0 0.0.255.255 area 1 (you are avoiding configuring
multiple entries)
Pls note that the order of the network statements does matter!. For ex. In
the 2nd method, if you reverse the order of the network statements, ospf
will not consider 172.16.1.1 under area 0 because 172.16.0.0 matches it and
you will have problems!.
HTH
Harish
"Ahmed Al-Ghawas"
<ghawas@batelco.c To: <ccielab@groupstudy.co
m>
om.bh> cc:
Sent by: Subject: OSPF wildcard bits
nobody@groupstudy
.com
06/29/2002 12:36
PM
Please respond to
"Ahmed Al-Ghawas"
Guys,
I am really getting confused!
>From what I understood from "CCIE Practical Studies" book that when using
the
network command, that you ought to be precise in the extent that you would
add
the interface ip address and not advertise the whole subnet mask!
For example:
R1
S0:10.1.128.1/24
|
|
S0:10.1.128.2/24
R2
S1:10.1.80.1/24
|
|
S1:10.1.80.3/24
R3
R1 config:
router ospf 2001
network 10.1.128.1 0.0.0.0 area x (and not; network 10.1.128.0 0.0.0.255
area
x!!)
R2 config:
router ospf 2001
network 10.1.128.2 0.0.0.0 area x (and not; network 10.1.128.0 0.0.0.255
area
x!!)
network 10.1.80.1 0.0.0.0 area x (and not; network 10.1.80.0 0.0.0.255 area
x!!)
R3 config:
router ospf 2001
network 10.1.80.3 0.0.0.0 area x (and not; network 10.1.80.0 0.0.0.255 area
x!!)
I really need to stick to one concept and understand why this book doest it
differently then the other and avoid loosing marks for such stupid thing in
the real lab!!
Any input is much appreciated
Ahmed
This archive was generated by hypermail 2.1.4 : Tue Jul 02 2002 - 08:12:44 GMT-3