From: ccie2be (ccie2be@nyc.rr.com)
Date: Thu Mar 17 2005 - 22:07:43 GMT-3
Sumit,
Thanks for getting back to me. I really appreciate it.
Your example shows me the piece I was missing - that "match ip next-hop 10".
Damn it, there's always something.
As best as you can tell, what's wrong with the MQC method?
As I said, I did a little testing and it seemed to work but I didn't have a
chance to test every possibility.
Thanks again, Tim
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Sumit
Sent: Thursday, March 17, 2005 7:48 PM
To: ccie2be; Group Study
Subject: Re: MQC vs Policy Routing
Tim,
PBR is the best match for this solution, you will use PBR route-map as:
access-list 10 permit <RB FR intreface add>
access-list 10 permit <RC FR interface add>
access-list 101 permit ip vlan1 any prec 3
route-map 10 IF-IP-PREC-3-GOTO-RC
match ip add 101
match ip next-hop 10
set ip next-hop (RA-RC int)
set ip default next-hop (RA-RB int)
and apply policy-route map to E0/0
hth
Sumit
----- Original Message -----
From: "ccie2be" <ccie2be@nyc.rr.com>
To: "Group Study" <ccielab@groupstudy.com>
Sent: Thursday, March 17, 2005 11:54 AM
Subject: MQC vs Policy Routing
> Hi guys,
>
>
>
> This problem stumped me. I didn't like either of the 2 solutions that
came
> to mind and would like to hear your thoughts.
>
>
>
> =============================
>
> Figure 1
>
>
>
> / -- R-B
>
> | ---- e0/0 R-A -- p2m f/r other networks with
different
> major network addresses
>
> \ -- R-C
>
>
>
> ==============================
>
> Figure 2
>
>
>
> R-A e0/0 ---- vlan 1 ------ R-d ----- R-e
>
>
>
> ==============================
>
>
>
>
>
> R-A is connected to vlan 1 via it's e0/0 interface and to R-d via vlan 1
and
> other subnets beyond that. (Fig 2)
>
>
>
> R-A is also connected to R-B and R-C via p2m f/r and can reach other
> networks behind R-B and R-C (Fig 1)
>
>
>
> I want R-A to forward packets that originate on vlan 1 and are heading to
> R-B or R-C or beyond and have an ip prec of x to take the pvc to R-C if
it's
> available.
>
>
>
> If the pvc or R-C is down, take the other pvc. All networks behind R-B or
> R-C can be reached via either pvc.
>
>
>
> I'm not sure how to config this.
>
>
>
> I thought of policy routing but this was the problem I couldn't figure
out.
> Suppose packets originating on vlan 1 weren't suppose to head towards R-B
or
> R-C? Wouldn't they just end up going to R-C or R-B only for these routers
> to send them back to R-A. ? And, thus waste bandwidth?
>
>
>
> Here's the pseudo code:
>
>
>
> route-map 10 IF-IP-PREC-3-GOTO-RC
>
> match ip-prec-3 and source = vlan1
>
> set ip next-hop R-C
>
>
>
> route-map 20 IF-IP-PREC-3-GOTO-RC
>
>
>
> ***********************************************
>
>
>
> The other solution I thought of was to use MQC:
>
>
>
> Assume the dlci to R-B = dlci-B and the dlci to R-C = dlci-C.
>
>
>
> Here's the pseudo code:
>
>
>
> access-list 100 permit ip vlan1 any prec 3
>
>
>
> class-map match-all IP-PREC
>
> match int e0/0 <-- Is this needed?
>
> match ip address 100
>
>
>
> policy-map IP-PREC
>
> class IP-PREC
>
> set fr-dlci <pvc-C>
>
>
>
> int f/r p2m
>
> service-policy out IP-PREC
>
>
>
> *****************************************************
>
>
>
> I never used the set fr-dlci command before and so I'm not 100% sure this
> solution actually works but I pretty sure it does. (I put an acl on R-C
and
> then did some pings and saw the matching packets go up but I didn't do any
> other testing.)
>
>
>
> Q?
>
>
>
> Will both solutions actually work?
>
>
>
> Is the MQC solution better?
>
>
>
> Is there a better solution I didn't think of?
>
>
>
> TIA, Tim
>
> _______________________________________________________________________
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