[172257] in North American Network Operators' Group
FW: Getting pretty close to default IPv4 route maximum for
daemon@ATHENA.MIT.EDU (John van Oppen)
Mon Jun 9 15:31:14 2014
X-Original-To: nanog@nanog.org
From: John van Oppen <jvanoppen@spectrumnet.us>
To: "nanog@nanog.org" <nanog@nanog.org>
Date: Mon, 9 Jun 2014 19:27:47 +0000
In-Reply-To: <Pine.LNX.4.61.1406091459050.10544@soloth.lewis.org>
Errors-To: nanog-bounces@nanog.org
It is generally much better to do the following:
mls cef maximum-routes ipv6 90
mls cef maximum-routes ip-multicast 1
This will leave v4 and mpls in one big pool, puts v6 to something useful fo=
r quite a while and steals all of the multicast space which is not really u=
sed on most deployments.
This gives us the following (which is pretty great for IP backbone purposes=
in dual stack):
#show mls cef maximum-routes=20
FIB TCAM maximum routes :
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Current :-
-------
IPv4 + MPLS - 832k (default)
IPv6 - 90k=20
IP multicast - 1k=20
John
-----Original Message-----
From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Jon Lewis
Sent: Monday, June 09, 2014 12:10 PM
To: Pete Lumbis
Cc: nanog@nanog.org
Subject: Re: Getting pretty close to default IPv4 route maximum for 6500/76=
00routers.
Why, in your example, do you bias the split so heavily toward IPv4 that the=
router won't be able to handle a current full v6 table? I've been using
mls cef maximum-routes ip 768
which is probably still a little too liberal for IPv6
FIB TCAM maximum routes :
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Current :-
-------
IPv4 - 768k
MPLS - 16k (default)
IPv6 + IP Multicast - 120k (default)
given that a full v6 table is around 17k routes today.
A more important question though is how many 6500/7600 routers will fully s=
urvive the reload required to affect this change? I've lost a blade (presu=
mably to the bad memory issue) each time I've rebooted a 6500 to apply this=
.
On Mon, 9 Jun 2014, Pete Lumbis wrote:
> The doc on how to adjust the 6500/7600 TCAM space was just published.
>
> http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-serie
> s-switches/117712-problemsolution-cat6500-00.html
>
>
> On Tue, May 6, 2014 at 3:48 PM, Pete Lumbis <alumbis@gmail.com> wrote:
>
>> There is currently a doc for the ASR9k. We're working on getting on=20
>> for
>> 6500 as well.
>>
>>
>> http://www.cisco.com/c/en/us/support/docs/routers/asr-9000-series-agg
>> regation-services-routers/116999-problem-line-card-00.html
>>
>>
>>
>>
>> On Tue, May 6, 2014 at 1:34 PM, <bedard.phil@gmail.com> wrote:
>>
>>> I would like to see Cisco send something out...
>>>
>>> -----Original Message-----
>>> From: "Drew Weaver" <drew.weaver@thenap.com>
>>> Sent: =FF=FF5/=FF=FF6/=FF=FF2014 11:42 AM
>>> To: "'nanog@nanog.org'" <nanog@nanog.org>
>>> Subject: Getting pretty close to default IPv4 route maximum for=20
>>> 6500/7600routers.
>>>
>>> Hi all,
>>>
>>> I am wondering if maybe we should make some kind of concerted effort=20
>>> to remind folks about the IPv4 routing table inching closer and=20
>>> closer to the 512K route mark.
>>>
>>> We are at about 94/95% right now of 512K.
>>>
>>> For most of us, the 512K route mark is arbitrary but for a lot of=20
>>> folks who may still be running 6500/7600 or other routers which are=20
>>> by default configured to crash and burn after 512K routes; it may be=20
>>> a valuable public service.
>>>
>>> Even if you don't have this scenario in your network today; chances=20
>>> are you connect to someone who connects to someone who connects to=20
>>> someone
>>> (etc...) that does.
>>>
>>> In case anyone wants to check on a 6500, you can run: show platform=20
>>> hardware capacity pfc and then look under L3 Forwarding Resources.
>>>
>>> Just something to think about before it becomes a story the=20
>>> community talks about for the next decade.
>>>
>>> -Drew
>>>
>>>
>>
>
----------------------------------------------------------------------
Jon Lewis, MCP :) | I route
| therefore you are _________ http://www.lew=
is.org/~jlewis/pgp for PGP public key_________
