11-03-2012 12:50 AM - edited 03-07-2019 09:50 AM
I am creating an extended access list in cisco 3560 as below
permit ip 10.65.1.0 0.1.255.255 host 10.0.0.1
permit ip 10.65.1.0 0.1.255.255 host 10.0.0.2
permit ip 10.65.1.0 0.1.255.255 host 10.0.0.3
But when I see the ACL by show ip access-list the subnet changes like below
permit ip 10.64.1.0 0.1.255.255 host 10.0.0.1
permit ip 10.64.1.0 0.1.255.255 host 10.0.0.2
permit ip 10.64.1.0 0.1.255.255 host 10.0.0.3
11-03-2012 01:39 AM
Yasir,
It is becasue it corrected your statement rightly as below
permit ip 10.64.1.0 0.1.255.255 host 10.0.0.1
Your wild card mask is 0.1.255.255
your 2nd octect(00000001) in wild card mask says to don't care that last bit in that octect. When you do that, your network statement should have 0 as last bit of your 2nd Octect
But 65 has last bit as 1.
65= 01000001 --- > last bit is one here
IOS corrected it by making the last bit as 0
64= 01000000
Thank you
Raju
11-03-2012 01:44 AM
Thanks Raju for your kind reply. It means that i will face this issue for every subnet containing 5, i.e.
10.5.0.0 /23 will become 10.4.0.0 and
10.15.0.0/23 will become 10.14.0.0.
Now I understand why it was happening.Thankyou
11-03-2012 05:40 AM
Hi Yasir,
your original question was having sunbet /15. not /23
When you use /15, 2nd octect of the network has to be an even number
So subnet will be like below
10.0.0.0/15
10.2.0.0/15
10.4.0.0/15
10.6.0.0/15
10.8.0.0/15
.......
.......
10.254.0.0/15
Thanks
Raju
11-03-2012 04:09 AM
Address: 10.65.1.0 00001010.0100000 1.00000001.00000000
Netmask: 255.254.0.0 = 15 11111111.1111111 0.00000000.00000000
Wildcard: 0.1.255.255 00000000.0000000 1.11111111.11111111
=>
Network: 10.64.0.0/15 00001010.0100000 0.00000000.00000000 (Class A)
Broadcast: 10.65.255.255 00001010.0100000 1.11111111.11111111
HostMin: 10.64.0.1 00001010.0100000 0.00000000.00000001
HostMax: 10.65.255.254 00001010.0100000 1.11111111.11111110
Address: 10.65.1.0 00001010.0100000 1.00000001.00000000
Netmask: 255.254.0.0 = 15 11111111.1111111 0.00000000.00000000
Wildcard: 0.1.255.255 00000000.0000000 1.11111111.11111111
=>
Network: 10.64.0.0/15 00001010.0100000 0.00000000.00000000 (Class A)
Broadcast: 10.65.255.255 00001010.0100000 1.11111111.11111111
HostMin: 10.64.0.1 00001010.0100000 0.00000000.00000001
HostMax: 10.65.255.254 00001010.0100000 1.11111111.11111110
please rate helpful posts
Regards
Thanveer
"Everybody is genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is a stupid."
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