[j-nsp] L2VPN debugging...

Mon Feb 15 15:57:25 EST 2010

So R4 peers with R5 via cebgp as well as R6 peers with R5 with cibgp. R4 uses 10.0.2.10 as the protocol next-hop for advertising L2VPN prefixes to R5 (RR) and to R6 (via RR). However, your LSP from R4-to-R6 is established to address 10.0.3.4 address. So in summary,

 *   This is an Inter-AS L2VPN scenario
 *   Protocol next-hop (PNH) advertised by R4 does not have any LSP to it from R6.

What you did looks like a hack to get the LSP going between R4 and R6 from R6. Another way (but probably more complex) to do it would be to create an inter-AS LSP between R4 and R6 via R5 with R5 (ASBR) distributing the R6 loopback address (or LSP endpoint) via BGP labeled-unicast family. R4 (ASBR) will in this case redistribute its own loopback via family labeled-unicast as well. Both ASBR will implement appropriate SWAP/PUSH operation to extend the LSP between R4s and R6s loopback addresses across the AS boundaries. I may have something similar in the configuration format if you are interested. I can unicast it to you.

Thanks,
Nilesh.

On 2/15/10 10:57 AM, "Hoogen" <hoogen82 at gmail.com> wrote:

R5 and R6 are in sub confed 65001 and R4 is in subconfed 65000.

lab at r6# run show route table vpnc extensive

vpnc-1.l2vpn.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
10.0.3.4:1:1:1/96 (1 entry, 1 announced)
        *BGP    Preference: 170/-101
                Route Distinguisher: 10.0.3.4:1 <http://10.0.3.4:1>
                Next-hop reference count: 4
                Source: 10.0.3.5
                Protocol next hop: 10.0.2.10
                Indirect next hop: 2 no-forward
                State: <Secondary Active Int Ext>
                Local AS: 65001 Peer AS: 65001
                Age: 5:08       Metric2: 1
                Task: BGP_65001.10.0.3.5+2193
                Announcement bits (1): 0-vpnc-1-l2vpn
                AS path: (65000) I
                Communities: target:65412:300 Layer2-info: encaps:VLAN, control flags:Control-Word, mtu: 0
                Label-base: 800002, range: 2, status-vector: 0x80
                Localpref: 100
                Router ID: 10.0.3.5
                Primary Routing Table bgp.l2vpn.0
                Indirect next hops: 1
                        Protocol next hop: 10.0.2.10 Metric: 30
                        Indirect next hop: 2 no-forward
                        Indirect path forwarding next hops: 1
                                Next hop: 10.0.2.14 via ge-0/0/3.0 weight 0x1
                        10.0.2.10/32 <http://10.0.2.10/32>  Originating RIB: inet.3
                          Metric: 30                      Node path count: 1
                          Forwarding nexthops: 1
                                Nexthop: 10.0.2.14 via ge-0/0/3.0

10.0.9.6:2:2:1/96 (1 entry, 1 announced)
TSI:
Page 0 idx 0 Type 1 val 87b0918
        *L2VPN  Preference: 170/-101
                Next-hop reference count: 2
                Protocol next hop: 10.0.9.6
                Indirect next hop: 0 -
                State: <Active Int Ext>
                Age: 12:56:45   Metric2: 1
                Task: vpnc-1-l2vpn
                Announcement bits (1): 1-BGP RT Background
                AS path: I
                Communities: Layer2-info: encaps:VLAN, control flags:Control-Word, mtu: 0
                Label-base: 800004, range: 1, status-vector: 0x0

        [edit]
lab at r6#

lab at r6# run show route 10.0.2.10

inet.0: 29 destinations, 29 routes (29 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.2.8/30 <http://10.0.2.8/30>         *[IS-IS/15] 01:09:56, metric 20
                    > to 10.0.8.6 via ge-0/0/2.0

[edit]
lab at r6#

I then installed the 10.0.2.10 prefix into the LSP and the VC came up...

lab at r6# run show route 10.0.2.10

inet.0: 29 destinations, 29 routes (29 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.2.8/30 <http://10.0.2.8/30>         *[IS-IS/15] 01:17:37, metric 20
                    > to 10.0.8.6 via ge-0/0/2.0

inet.3: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.2.10/32 <http://10.0.2.10/32>        *[RSVP/7] 00:07:03, metric 30
                    > to 10.0.2.14 via ge-0/0/3.0, label-switched-path r6-r4

[edit]
lab at r6#

lab at r6# run show route table vpnc

vpnc-1.l2vpn.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.3.4:1:1:1/96
                   *[BGP/170] 00:07:19, localpref 100, from 10.0.3.5
                      AS path: (65000) I
                    > to 10.0.2.14 via ge-0/0/3.0, label-switched-path r6-r4
10.0.9.6:2:2:1/96
                   *[L2VPN/170/-101] 12:58:56, metric2 1
                      Indirect

[edit]
lab at r6#

Thank you for your help Nilesh. Do you have a link that I could read up for more troubleshooting tips on L3/L2 VPN's..

Thanks again.
Hoogen

On Mon, Feb 15, 2010 at 9:35 AM, Nilesh Khambal <nkhambal at juniper.net> wrote:
Why is the below route on R6, isn’t pointing to any LSP towards R4? Is route reflector changing the protocol next-hop of the route coming from R4?

<...>
10.0.3.4:1:1:1/96                <--------Receiving the R4 loopback..
                   *[BGP/170] 00:07:30, localpref 100, from 10.0.3.5
                      AS path: (65000) I
                    > to 10.0.8.6 via ge-0/0/2.0
<...>

Thanks,
Nilesh.