From: Scott M Vermillion (scott_ccie_list@it-ag.com)
Date: Mon Oct 27 2008 - 17:58:21 ARST
Can't say 100% for certain in the particular case, but a lot of times when
you see a command that allows for variations that either include or exclude
'ip', it's because an 'ipv6' variation was introduced. So since there's a
new 'ipv6' variation, they throw 'ip' into the syntax to explicitly chose
IPv4. Likewise, Cisco from time to time tweaks the syntax of commands to
add additional functionality or flexibility. Check out what IOS does with
the command as listed below (the first one that's referencing TCP port 80):
R1(config)#priority-list 1 protocol ip high tcp 80
R1(config)#do sh run | inc priority
priority-list 1 protocol ip high tcp www
This is not the only case where there are options to specify 'http' or 'www'
or 'tcp 80', depending on the syntax you chose (or are forced to chose,
depending on the IOS version you happen to be standing in front of) and it's
also not the only example of IOS placing the command in the config as it
deems appropriate, regardless of what you may have typed.
I haven't labbed this specific example (a little tight on time at the
moment), so I again stress that this is more of a generic "response" than a
specific "answer." It kind of adds up, though, when you consider that there
would be no way to invoke IPv6 with the second syntax:
R1(config)#priority-list 1 protocol http high ?
gt Prioritize packets greater than a specified size
lt Prioritize packets less than a specified size
<cr>
Whereas:
R1(config)#priority-list 1 protocol ipv6 high ?
gt Prioritize packets greater than a specified size
lt Prioritize packets less than a specified size
<cr>
(and it would appear that your options (in terms of referencing an ACL, a L4
transport/port number, or upper-layer protocol keyword) are considerably
limited with IPv6 vs. IPv4, but at least there's *some* support for the
protocol with that syntax - and that's often times the case with IPv6 in
IOS)
Cheers,
Scott
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Jason Madsen
Sent: Monday, October 27, 2008 12:53 PM
To: Hobbs
Cc: Cisco certification
Subject: Re: Priority List Usage
it worked fine for me on a couple of different platforms of which used
fairly new IOS's. the commands were accepted as they both appeared in
my "show queueing" output also.
anyone able to distinguish between the two commands?
Jason
On 10/27/08, Hobbs <deadheadblues@gmail.com> wrote:
> I don't think the second one is a command is it?
>
> priority-list 1 protocol http ?
> % Unrecognized command
>
> On Sat, Oct 25, 2008 at 11:09 PM, Jason Madsen
> <madsen.jason@gmail.com>wrote:
>
>> Hi Group,
>>
>> I was wondering if anyone knows the difference between the following
>> priority list examples:
>>
>>
>> priority-list 1 protocol ip high tcp 80
>>
>> and
>>
>> priority-list 1 protocol http high
>>
>> I'm a bit tired so I could be missing the obvious here, but the config'
>> guide and command reference aren't of much help in this matter and the
two
>> statements pretty much seem the same to me.
>>
>> Thanks,
>> Jason
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
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