It's kind of wierd. The source portion of the access list defines the
network whose updates are permited/denied...no suprise...the wierd part is
that the destination portion specifies the subnet mask of that network. So,
in your example;

access-list 100 permit ip 192.108.0.0 0.0.0.0 255.255.0.0 0.0.0.0
( 192.108.0.0 [wildcard] 0.0.0.0 [subnet mask] 255.255.0.0 [wildcard]
0.0.0.0)
( 192.108.0.0/16 will be advertised )

Maybe someone else can jump in...because the wildcard is 0.0.0.0 does it
mean that any other VLSM networks under the 192.108.0.0/16 supernet would
also be advertised?

access-list 100 deny ip 192.108.0.0 0.0.255.255 255.255.0.0 0.0.255.255
( 192.108.0.0 [wildcard] 0.0.255.255 [ subnet mask ] 255.255.0.0 [wildcard ]
0.0.255.255)
(192.108.0.0/16 would be denied...the last two octets are ignored )

I'm new to all this and learning it myself...so please...someone correct me
if I am wrong or add to my comments. Thanks. Dain.
""Hunt Lee""  wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> Hi all,
>
> Can anyone please explain this to me?? I have read some examples regarding
> neighbor x.x.x.x distribute-list  in | out using extended Access-List
> from CCO, Internet Routing Arch (by Halabi) & BGP 4 Command & Reference
(by
> Parkhurst), yet I'm still very confused.
>
> Below is one of them
>
> neighbor 120.23.4.1 distribute-list 100 in
>
> access-list 100 permit ip 192.108.0.0 0.0.0.0 255.255.0.0 0.0.0.0
>
> access-list 100 deny ip 192.108.0.0 0.0.255.255 255.255.0.0 0.0.255.255
>
>
>
> How do you read these things?? Any help will be greatly appreciated.
>
> Thanks,
>
> Hunt




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