[c-nsp] Multilink PPP Was -> Re: Balancing T1's with CEF

Jeff Wojciechowski Jeff.Wojciechowski at midlandpaper.com
Thu Jul 30 14:22:21 EDT 2009 

We are going to be deploying some more MLPPP ckts here in the next few months and I am not familiar with ADCs. Are those carrier dependant? Does this affect MPLS QoS?

Thanks,

-Jeff


-----Original Message-----
From: Frank Bulk - iName.com [mailto:frnkblk at iname.com] 
Sent: Thursday, July 30, 2009 1:19 PM
To: Jeff Wojciechowski; cisco at peakpeak.com; cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] Multilink PPP Was -> Re: Balancing T1's with CEF

All of this is further confirmation that if its IP that you need to send
over multiple T1's, much better to get an ADC or like box that does Ethernet
over one or more "raw" T-1's.  Abstracts the whole transport issue, and
gives Ethernet interfaces on both sides.

Frank

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Jeff Wojciechowski
Sent: Thursday, July 30, 2009 11:02 AM
To: cisco at peakpeak.com
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Multilink PPP Was -> Re: Balancing T1's with CEF

We had a problem with balancing 3 T1s between 2 T1s on a dual port T1
controller WIC and the 3rd on a single port service module. Cisco TAC swore
up and down that it SHOULD balance between the 2 types of WICs but more
traffic was being sent over the WIC T1-DSU. Replacing the WIC 1-DSU with the
controller did the trick. (And that's actually the problem that helped me
find this wonderful list...THANKS!)

-Jeff


-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Brian Raaen
Sent: Thursday, July 30, 2009 10:38 AM
To: cisco at peakpeak.com
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Multilink PPP Was -> Re: Balancing T1's with CEF

Here is what I have on a multi-link with AT&T.

interface Multilink1
 description XXXXX
 ip address XXX.XXX.XXX.XXX 255.255.255.252  load-interval 30  no keepalive
no cdp enable  ppp multilink  ppp multilink fragment disable  ppp multilink
group 1

interface Serial1/0:0
 description XXXXXXX
 bandwidth 1536
 no ip address
 encapsulation ppp
 no fair-queue
 no cdp enable
 ppp multilink
 ppp multilink group 1
 max-reserved-bandwidth 100




Security Team wrote:
> Well.....we arent' doing per packet and the destinations are 
> definitely different.
>
> The last time this problem occurred I did a clear ip cache and it went
away.
> Since it isn't doing it this time I guess I thought I should try 
> something else.
>
> Here is what I tried, I tried converting to multilink ppp encaps 
> instead of HDLC to see if that would have any effect, and it didn't.
>
> (on both ends):
>
> aaa new-model
> aaa authorization network noauth none
> aaa session-id common
>
> interface Multilink1
>  no ip address
>  load-interval 30
>  no cdp enable
>  ppp authorization noauth
>  ppp multilink
>  ppp multilink group 1
>  no shut
> !
> Interface Serial1/1/0
>  encapsulation ppp
>  ppp authorization noauth
>  shut
>  no shut
> !
> Interface Serial1/1/3
>  encapsulation ppp
>  ppp authorization noauth
>  shut
>  no shut
> !
> Interface Serial1/0/0/12:0
>  encapsulation ppp
>  ppp authorization noauth
>  shut
>  no shut
>
> So with 3 static routes like this:
>
> ip route x.y.z.0 255.255.255.0 serial1/1/0 ip route x.y.z.0 
> 255.255.255.0 serial1/1/3 ip route x.y.z.0 255.255.255.0 
> serial1/0/0/12:0
>
> The customer works but still has the problem where all the traffic 
> sacks one line inbound to their 28xx from our 7507.  So all we 
> accomplished here really was pre-build a multilink PPP bundle but just 
> change the encaps for each serial interface to PPP instead of HDLC.
>
> Then I thought what I'd do is add each serial interface to the 
> multilink bundle using:
>
> Int Serial1/1/0
>    ppp multilink
>    ppp multilink group 1
> Int Serial1/1/3
>    ppp multilink
>    ppp multilink group 1
> Int Serial1/0/0/12:0
>    ppp multilink
>    ppp multilink group 1
>
> That is when the fun stopped (no packets routed at all). I did get 
> this message on the console:
>
> Jul 30 09:03:09 MDT: %RP_MLP-5-LINKTYPEMISMATCH: 
> Link(Serial1/0/0/12:0) added, Bundle(Multilink1) may not be 
> distributed
>
> Not sure what this means.
>
> So I assume what I should have done in addition to adding the ppp 
> multilink grouping to the serial interfaces is remove the static 
> routes and replace them with this instead right?
>
> ip route x.y.z.0 255.255.255.0 Multilink1
>
> I haven't ever configured multilink PPP before but this is right isn't it?
>
> Thanks,
> CJ
>
>
> On 7/30/09 7:32 AM, "Matthew Huff" <mhuff at ox.com> wrote:
>
>   
>> Unless you do "per-packet" load-sharing (which you don't want to do 
>> since it's cpu switched), the path is session based. If most of the 
>> traffic is going from one source to one destination, it won't be 
>> load-shared. What do the routing tables look like in both directions?
>>
>> ----
>> Matthew Huff       | One Manhattanville Rd
>> OTA Management LLC | Purchase, NY 10577 http://www.ox.com  | Phone: 
>> 914-460-4039
>> aim: matthewbhuff  | Fax:   914-460-4139
>>
>>
>>     
>>> -----Original Message-----
>>> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp- 
>>> bounces at puck.nether.net] On Behalf Of Security Team
>>> Sent: Wednesday, July 29, 2009 11:24 PM
>>> To: cisco-nsp at puck.nether.net
>>> Subject: [c-nsp] Balancing T1's with CEF
>>>
>>> I rebooted a 7507 router that had a site connected with 3 T1's and 
>>> now all the traffic is nailing one line instead of being distributed 
>>> over all 3 using the static routes/CEF.
>>>
>>> I did look at the Cisco troubleshooting tips but didn't see anything 
>>> immensely helpful.  Here is a config snippet on the 7507 side (it's 
>>> obviously nothing whizzy).
>>>
>>> Has anyone seen this before?  I did an ip clear cache and also tried 
>>> doing a shut/no shut on each line individually on the 7507, but the 
>>> traffic to the customer's 28xx router always sacks one line.  It 
>>> seems like in the past I did some kind of clear on the 7507 and 
>>> things got better, but I can't recall what that may have been.
>>>
>>> Thanks,
>>> CJ
>>>
>>> 7507 (all PA adapters on the same VIP) config. One T1 comes in on a 
>>> chan DS3 card breaking out individual T1¹s, and the other 2 T1¹s 
>>> come in on a 4- port PA adapter T1 card. I¹m not using dCEF since I 
>>> have never had good luck with it.
>>>
>>> ip cef
>>> !
>>> interface Serial1/0/0/12:0
>>>  bandwidth 1536
>>>  ip address x.x.x.x y.y.y.y
>>>  load-interval 30
>>>  no fair-queue
>>>  down-when-looped
>>>  no cdp enable
>>> !
>>> interface Serial1/1/0
>>>  bandwidth 1536
>>>  ip address x.x.x.x y.y.y.y
>>>  load-interval 30
>>>  no fair-queue
>>>  down-when-looped
>>>  no cdp enable
>>> !
>>> interface Serial1/1/3
>>>  bandwidth 1536
>>>  ip address x.x.x.x y.y.y.y
>>>  load-interval 30
>>>  no fair-queue
>>>  down-when-looped
>>>  no cdp enable
>>>
>>> _______________________________________________
>>> cisco-nsp mailing list  cisco-nsp at puck.nether.net 
>>> https://puck.nether.net/mailman/listinfo/cisco-nsp
>>> archive at http://puck.nether.net/pipermail/cisco-nsp/
>>>       
>
>
> _______________________________________________
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>   

--
-----------------
Brian Raaen
Network Engineer
email: /braaen at zcorum.com/ <mailto:braaen at zcorum.com> Telephone
/678-507-5000x5574/
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