Question (kinda operational).. I've been looking/asking around, but have yet been able to get the same answer twice to the following question: How many links can you have in parallel when using CEF load-sharing per-packet? Another words, we currently have a site that has four DS1s load balanced, in parallel (terminating in the same router on each end). Can you add a [5th|6th|7th|8th] ? Before you answer "BUY A DS3!", this is located in a rural area that a) really doesn't (easily) even have DS3 capabilites, and b) isn't cost effective to have a DS3 as it is about 15 times the cost of a DS1. Thanks for any insight!
On Fri, Jan 14, 2000 at 11:41:47PM -0500, Alex Rubenstein wrote:
I've been looking/asking around, but have yet been able to get the same answer twice to the following question: How many links can you have in parallel when using CEF load-sharing per-packet?
Another words, we currently have a site that has four DS1s load balanced, in parallel (terminating in the same router on each end). Can you add a [5th|6th|7th|8th] ?
A maximum of 6 parallel path's, and that is depending on the type of routing over this link (6 applies to static, bgp, ospf and isis when configuring maximum-paths) router(config-router)#maximum-paths ? <1-6> Number of paths /Jesper -- Jesper Skriver, jesper(at)skriver(dot)dk - CCIE# 5456 Work: Network manager @ AS3292 (Tele Danmark DataNetworks) Private: Geek @ AS2109 (A much smaller network ;-) One Unix to rule them all, One Resolver to find them, One IP to bring them all and in the zone to bind them.
How stable is IOS 12? We tried CEF some time ago, and the build wasn't stable. I'd sure like to use it, assuming everything works. WSimpson@UMich.edu Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32
In 2 words: IOS 12 is stable, some it's features are not -:). It's almost safe to use it, if you can turn off features which cause troubles. CEF is not trouble-making feature except some configurations. Btw, you don't need not CEF no 12.x to make load balancing by the 4 lines - it work fine in all versions, if you use hiddn 'service internal' command and install short cache time-to-live. On Sun, 16 Jan 2000, William Allen Simpson wrote:
Date: Sun, 16 Jan 2000 03:45:04 -0500 From: William Allen Simpson <wsimpson@greendragon.com> To: nanog@merit.edu Subject: Re: CEF Load balancing...
How stable is IOS 12? We tried CEF some time ago, and the build wasn't stable. I'd sure like to use it, assuming everything works.
WSimpson@UMich.edu Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32
Aleksei Roudnev, (+1 415) 585-3489 /San Francisco CA/
It's almost safe to use it, if you can turn off features which cause troubles. CEF is not trouble-making feature except some configurations. Except when the router decides to turn CEF off all by itself due to malloc failure. Mark.
On Sun, Jan 16, 2000 at 10:25:37PM +1030, Mark Prior wrote:
It's almost safe to use it, if you can turn off features which cause troubles. CEF is not trouble-making feature except some configurations.
Except when the router decides to turn CEF off all by itself due to malloc failure.
That sounds like a memory leak, have you tried the latest versions ? in 12.0(x)S there was a catastrophic memory leak in 12.0(7)S related to cef ... /Jesper -- Jesper Skriver, jesper(at)skriver(dot)dk - CCIE# 5456 Work: Network manager @ AS3292 (Tele Danmark DataNetworks) Private: Geek @ AS2109 (A much smaller network ;-) One Unix to rule them all, One Resolver to find them, One IP to bring them all and in the zone to bind them.
> It's almost safe to use it, if you can turn off features which cause troubles. > CEF is not trouble-making feature except some configurations. > > Except when the router decides to turn CEF off all by itself due to > malloc failure. That sounds like a memory leak, have you tried the latest versions ? in 12.0(x)S there was a catastrophic memory leak in 12.0(7)S related to cef ... It's more bizarre than that since show memory indicates its got plenty so its either recovering it somehow or confused. I would suggest that later. We're running the latest code, well not quite (only 12.0(8)S rather than 12.0(8.3)S, but we are sick of catastrophic failures and 12.0(8)S seems stable enough, or more exactly we don't need more bug introducing features. Mark.
On Sun, 16 Jan 2000, Mark Prior wrote:
It's almost safe to use it, if you can turn off features which cause troubles. CEF is not trouble-making feature except some configurations.
Except when the router decides to turn CEF off all by itself due to malloc failure.
Whic probably means it ran out of RAM; so add more.
Mark.
It's almost safe to use it, if you can turn off features which cause troubles. CEF is not trouble-making feature except some configurations.
Except when the router decides to turn CEF off all by itself due to malloc failure.
Mark.
So it has one minor glitch.. Yeesh! :-) ---------------------------------------------------------------------- Wayne Bouchard [Immagine Your ] web@typo.org [Company Name Here] Network Engineer ----------------------------------------------------------------------
How stable is IOS 12? We tried CEF some time ago, and the build wasn't stable. I'd sure like to use it, assuming everything works. We still have problems with it while running 12.0(8)S but it's getting better, probably because 12.1 will appear soon :-) It probably depends on what you are trying to do and how much memory you have (both in the CPU and on the VIPers if you have 7500s). Mark.
On Sun, 16 Jan 2000, William Allen Simpson wrote:
How stable is IOS 12? We tried CEF some time ago, and the build wasn't stable. I'd sure like to use it, assuming everything works.
CEF in general breaks weird and interesting things. In a "normal" router all should be ok. We have a situation where CEF in a particilar 12.0.x version broke the BVI interface in an IRB configuration w/ATM. Then the next version broke forwarding between an ATM interface and a Ethernet interface in an interesting way (I haven't tracked down the specifics on the second case yet.) All in all, CEF works wonders, if it doesn't break something with its extra-fancy forwarding. - Forrest W. Christian (forrestc@imach.com) KD7EHZ ---------------------------------------------------------------------- iMach, Ltd., P.O. Box 5749, Helena, MT 59604 http://www.imach.com Solutions for your high-tech problems. (406)-442-6648 ----------------------------------------------------------------------
CEF is safe to a point. We're running it on 11.1CC(30), and it runs pretty well. We had memory leak problems in earlier versions on the 11.1CC train. I wouldn't use it for IMUXing, though. Check out Tiara Networks for their MLPPP engine. It's pretty nifty. CEF does a nice job of bringing the CPU down on a fully loaded 7513. That's all i'd use it for, until all the bugs get worked out. I had a bad experience using CEF on 12.0.5 in the type of situation you are describing. If a serial flapped, there was a small chance that the router CPU would go nuts, effectively making the router unmanageable. On a related note - Any ISPs out there using 12.0(s) yet in widespread release? -------------------------------------------------------------- Daniel L. Golding * Senior Network Engineer Network Engineering * Mindspring Enterprises dgolding@mindspring.net * -------------------------------------------------------------- On Fri, 14 Jan 2000, Alex Rubenstein wrote:
Question (kinda operational)..
I've been looking/asking around, but have yet been able to get the same answer twice to the following question: How many links can you have in parallel when using CEF load-sharing per-packet?
Another words, we currently have a site that has four DS1s load balanced, in parallel (terminating in the same router on each end). Can you add a [5th|6th|7th|8th] ?
Before you answer "BUY A DS3!", this is located in a rural area that a) really doesn't (easily) even have DS3 capabilites, and b) isn't cost effective to have a DS3 as it is about 15 times the cost of a DS1.
Thanks for any insight!
A sh cdp neighbors detailed at AMS-IX last week revealed that roughly half of those running on 75xx/12xxx plaforms were running an IOS 12.0, mostly 12.0(5)S and newer. Slightly more than half of those on smaller Cisco platforms were also doing so. Of course, this doesn't mean they're using 12.0 releases elsewhere, but it's a fairly safe bet. There were some major players amongst those running 12.0, but I'm not sure it would be terribly appropriate to name names. Phil Sykes, Network Engineer Cable & Wireless Europe
-----Original Message----- From: Daniel Golding [mailto:dgolding@mindspring.net] Sent: 16 January 2000 19:13 To: Alex Rubenstein Cc: nanog@merit.edu Subject: Re: CEF Load balancing...
CEF is safe to a point. We're running it on 11.1CC(30), and it runs pretty well. We had memory leak problems in earlier versions on the 11.1CC train. I wouldn't use it for IMUXing, though. Check out Tiara Networks for their MLPPP engine. It's pretty nifty.
CEF does a nice job of bringing the CPU down on a fully loaded 7513. That's all i'd use it for, until all the bugs get worked out. I had a bad experience using CEF on 12.0.5 in the type of situation you are describing. If a serial flapped, there was a small chance that the router CPU would go nuts, effectively making the router unmanageable.
On a related note - Any ISPs out there using 12.0(s) yet in widespread release?
-------------------------------------------------------------- Daniel L. Golding * Senior Network Engineer Network Engineering * Mindspring Enterprises dgolding@mindspring.net * --------------------------------------------------------------
On Fri, 14 Jan 2000, Alex Rubenstein wrote:
Question (kinda operational)..
I've been looking/asking around, but have yet been able to get the
same
answer twice to the following question: How many links can you have in parallel when using CEF load-sharing per-packet?
Another words, we currently have a site that has four DS1s load balanced, in parallel (terminating in the same router on each end). Can you add a [5th|6th|7th|8th] ?
Before you answer "BUY A DS3!", this is located in a rural area that a) really doesn't (easily) even have DS3 capabilites, and b) isn't cost effective to have a DS3 as it is about 15 times the cost of a DS1.
Thanks for any insight!
On Sun, 16 Jan 2000 20:02:48 +0100 "Sykes, Phil" <phil.sykes@cweurope.net> wrote:
A sh cdp neighbors detailed at AMS-IX last week revealed that roughly half of those running on 75xx/12xxx plaforms were running an IOS 12.0, mostly 12.0(5)S and newer. Slightly more than half of those on smaller Cisco platforms were also doing so.
Of course, this doesn't mean they're using 12.0 releases elsewhere, but it's a fairly safe bet.
There were some major players amongst those running 12.0, but I'm not sure it would be terribly appropriate to name names.
If you need GSR power you really don't have a choice but to use 12. We're running 11.1.CC25 on our 7500's because we've never seen a release of 12 that works well with VIP2-50s. YMMV. We're about to use 12 on some new GSR boxes we have. Regards, Neil. -- Neil J. McRae - Alive and Kicking neil@DOMINO.ORG
participants (11)
-
Alex P. Rudnev -
Alex Rubenstein -
Daniel Golding -
Forrest W. Christian -
Jesper Skriver -
Mark Prior -
Neil J. McRae -
Randy Bush -
Sykes, Phil -
Wayne Bouchard -
William Allen Simpson