[j-nsp] Bonding multiple L2 Services with OSPF

[Steven Brenchley]

Does your carrier support aggregate links?

On Tue, Aug 25, 2009 at 7:59 AM, Ben Dale <bdale at comlinx.com.au> wrote:

> Hi all,
>
> I have a couple of J-Series plugged into a VPLS service (so essentially a
> large layer 2 domain).  I have a single subnet containing the WAN interfaces
> of each router, and I'm running an OSPF in order to distribute the
> LAN-facing subnets of each box.
>
> At one of my sites, the carrier was unable to deliver a single 1Mbps
> service, so instead they have delivered 2x 512Kbps circuits.  I have
> assigned each of the interfaces on the attached router an address in the
> same subnet (which JUNOS warns about, but commits anyway).  OSPF establishes
> on both interfaces, but the LAN subnet is only being learnt by other routers
> via one of the interfaces (presumably because the Router ID from both
> advertisements is the same).  Are there any knobs to get around this, or
> alternatively is there another way to bond the two interfaces (other than
> advertising half the LAN out each link)?  The usual per-packet forwarding
> ECMP options don't work here, because there aren't two prefixes being learnt
> by other routers.
>
> Lab config shown:
>
> ge-0/0/2 {
>    description "RegionA LAN";
>    unit 0 {
>        family inet {
>            address 192.168.102.254/24;
>        }
>    }
> }
> ge-0/0/2 {
>    description "xxx VPLS Link 1";
>    unit 0 {
>        family inet {
>            address 172.16.0.4/24;
>        }
>    }
> }
> ge-0/0/3 {
>    description "xxx VPLS Link 2";
>    unit 0 {
>        family inet {
>            address 172.16.0.3/24;
>        }
>    }
> }
> protocols {
>    ospf {
>        export export-direct;
>        area 0.0.0.0 {
>            interface ge-0/0/3.0;
>            interface ge-0/0/2.0;
>        }
>    }
> }
> policy-options {
>    policy-statement export-direct {
>        from {
>            protocol direct;
>            route-filter 192.168.0.0/16 prefix-length-range /24-/24;
>        }
>        then accept;
>    }
> }
>
> bdale at RegionB# run show ospf neighbor
> Address          Interface              State     ID               Pri
>  Dead
> 172.16.0.1       ge-0/0/2.0             Full      10.0.0.238       128
>  36
> 172.16.0.2       ge-0/0/2.0             Full      10.0.0.237       128
>  35
> 172.16.0.1       ge-0/0/3.0             Full      10.0.0.238       128
>  36
> 172.16.0.2       ge-0/0/3.0             Full      10.0.0.237       128
>  35
> ...
> bdale at DCRegion> show ospf route
> Topology default Route Table:
>
> Prefix             Path   Route       NH   Metric  NextHop       Nexthop
>                   Type   Type        Type         Interface     addr/label
> 10.0.0.236         Intra  AS BR       IP        1  ge-0/0/3.0    172.16.0.4
> 10.0.0.238         Intra  AS BR       IP        1  ge-0/0/3.0    172.16.0.1
> 172.16.0.0/24      Intra  Network     IP        1  ge-0/0/3.0
> 192.168.100.0/24   Ext2   Network     IP        0  ge-0/0/3.0
>  172.16.0.1
> 192.168.102.0/24   Ext2   Network     IP        0  ge-0/0/3.0
>  172.16.0.4
>
>
> Cheers,
>
> Ben
>
>
>
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>



-- 
Steven Brenchley
-------------------------------------
There are 10 types of people in the world those who understand binary and
those who don't.