[j-nsp] Issue with pseudo-wire attempting to establish across non LSP path
David Ball
davidtball at gmail.com
Wed Sep 28 23:40:11 EDT 2011
Hi Peter. If I understand correctly, you're expecting that the
pseudowire connecting your J42 and J43 VPLS endpoints will
re-establish itself using the LSPs that those routers have to
J41...essentially transiting through J41 using 2 individual LSPs.
Unfortunately that won't work by default, since the route from J43 to
J42 can no longer be resolved to an LSP in inet.3 (check 'sh route
table inet.3 72.22.160.240' from J43), which is a requirement for any
VPN.
Are you deactivating/deleting the LSP definitions between J42 and
J43? If so, what are you trying to simulate? A failed LSP or link
between J42 and J43? Depending on your configuration, if the link
between 42 and 43 fails, the LSP should resignal through J41 on its
own and while your VPNs may flap, they should restore fairly quickly
(or if you use one of the fast reroute methods for your LSPs, they
likely won't drop at all.
David
On 28 September 2011 20:01, Peter Kalogerakos <pjkpub at gmail.com> wrote:
> David,
> Each of the routers are running RSVP as the core MPLS protocol on the core
> facing interfaces in other words, we are not running LDP on the core.
>
> To clarify, these are VPLS connections. If you can visualize a ring type
> configuration where the top node BOXLABJ41 has a connection to BOXLABJ42 and
> BOXLABJ43. BOXLABJ42 and BOXLABJ43 also have a connection to each other.
> I also created a pair of named LSP's between
> - BOXLABJ41 and BOXLABJ42 (LSP2)
> - BOXLABJ41 and BOXLABJ43 (LSP1
> - BOXLABJ42 and BOXLABJ43 (LSP_J42-43)\(LSP_J43-J42)
> The issue exists when I remove the named LSP between BOXLABJ42 and
> BOXLABJ43. The vpls session, using vpls and pseudo-wire interchangeably,
> goes down when I disable the named LSP between J42 and J43. The VPLS session
> goes back up when I cost the IGP metrics to force IGP (ISIS) to prefer
> traffic across the links passing through BOXLABJ41 intermediate node.
> Below is a series of outputs demonstrating the working and failed
> conditions.
> admin at boxlabj41> show mpls lsp
> Ingress LSP: 2 sessions
> To From State Rt P ActivePath LSPname
> 72.22.160.205 72.22.160.241 Up 0 * LSP2
> 72.22.160.240 72.22.160.241 Up 0 * LSP1
> Total 2 displayed, Up 2, Down 0
> Egress LSP: 2 sessions
> To From State Rt Style Labelin Labelout LSPname
> 72.22.160.241 72.22.160.240 Up 0 1 FF 3 - LSP1
> 72.22.160.241 72.22.160.205 Up 0 1 FF 3 - LSP1
> Total 2 displayed, Up 2, Down 0
> ***
> admin at boxlabj42>show vpls connections instance ri_j42-j43 //output from
> router J43 Lo072.22.160.240
> Instance: ri_j42-j43
> Local site: boxlabj42.10002 (1)
> connection-site Type St Time last up # Up trans
> 2 rmt Up Sep 26 19:22:10 2011 2
> Remote PE: 72.22.160.205, Negotiated control-word: No
> Incoming label: 262154, Outgoing label: 262145
> Local interface: lsi.1564161, Status: Up, Encapsulation: VPLS
> Description: Intf - vpls ri_j42-j43 local site 1 remote site 2
> admin at boxlabj43> show vpls connections instance ri_j42-j43 //output from
> router J42 Lo072.22.160.205
> Instance: ri_j42-j43
> Local site: boxlabj43.10002 (2)
> connection-site Type St Time last up # Up trans
> 1 rmt Up Sep 26 22:13:40 2011 2
> Remote PE: 72.22.160.240, Negotiated control-word: No
> Incoming label: 262145, Outgoing label: 262154
> Local interface: lsi.1138567, Status: Up, Encapsulation: VPLS
> Description: Intf - vpls ri_j42-j43 local site 2 remote site 1
> *****
> admin at boxlabj43> show mpls lsp
> Ingress LSP: 2 sessions
> To From State Rt P ActivePath LSPname
> 72.22.160.240 72.22.160.205 Up 0 * LSP_J43-J42
> 72.22.160.241 72.22.160.205 Up 0 * LSP1
> Total 2 displayed, Up 2, Down 0
> Egress LSP: 2 sessions
> To From State Rt Style Labelin Labelout LSPname
> 72.22.160.205 72.22.160.240 Up 0 1 FF 3 - LSP_J42-43
> 72.22.160.205 72.22.160.241 Up 0 1 FF 3 - LSP2
> admin at boxlabj42> show mpls lsp
> Ingress LSP: 2 sessions
> To From State Rt P ActivePath LSPname
> 72.22.160.205 72.22.160.240 Up 0 * LSP_J42-43
> 72.22.160.241 72.22.160.240 Up 0 * LSP1
> Total 2 displayed, Up 2, Down 0
> Egress LSP: 2 sessions
> To From State Rt Style Labelin Labelout LSPname
> 72.22.160.240 72.22.160.205 Up 0 1 FF 3 -
> LSP_J43-J42
> 72.22.160.240 72.22.160.241 Up 0 1 FF 3 - LSP1
> ****
> admin at boxlabj42>show route
> *snip*
> ri_j42-j43.l2vpn.0: 2 destinations, 2 routes (2 active, 0 holddown, 0
> hidden)
> + = Active Route, - = Last Active, * = Both
> 72.22.160.205:10002:2:1/96
> *[BGP/170] 2d 05:45:52, localpref 100, from 72.22.160.241
> AS path: I
> > to 72.22.160.13 via ge-0/0/9.0, label-switched-path
> LSP_J42-43
> 72.22.160.240:10002:1:1/96
> *[L2VPN/170/-101] 2w2d 01:50:03, metric2 1
> Indirect
>
> admin at boxlabj43>show route
> *snip*
> ri_j42-j43.l2vpn.0: 2 destinations, 2 routes (2 active, 0 holddown, 0
> hidden)
> + = Active Route, - = Last Active, * = Both
> 72.22.160.205:10002:2:1/96
> *[L2VPN/170/-101] 2w2d 01:52:51, metric2 1
> Indirect
> 72.22.160.240:10002:1:1/96
> *[BGP/170] 2d 05:49:23, localpref 100, from 72.22.160.241
> AS path: I
> > to 72.22.160.12 via ge-0/0/9.0, label-switched-path
> LSP_J43-J42
> ***
> admin at boxlabj42> show configuration protocols mpls label-switched-path
> LSP_J42-43 | display set
> set protocols mpls label-switched-path LSP_J42-43 to 72.22.160.205
> admin at boxlabj43> show configuration protocols mpls label-switched-path
> LSP_J43-J42 | display set
> set protocols mpls label-switched-path LSP_J43-J42 to 72.22.160.240
>
> The following output demonstrates the non-working condition following the
> removal of the "label switched path LSP_J42-J43". The expectation is that
> the pseudo-wire will signal between the LERs BOXLABJ42 \ BOXLABJ43 across an
> established LSP, in this case LSP1 to LSP2 using BOXLABJ41 as the LSR rather
> that using non LSP direct-connect path.
> admin at boxlabj42> show vpls connections instance ri_j42-j43
> Instance: ri_j42-j43
> Local site: boxlabj42.10002 (1)
> connection-site Type St Time last up # Up trans
> 2 rmt VC-Dn Sep 26 19:22:10 2011 2
> Remote PE: 72.22.160.205, Negotiated control-word: No
> Incoming label: 262154, Outgoing label: 262145
> Local interface: lsi.1564161, Status: Up, Encapsulation: VPLS
> Description: Intf - vpls ri_j42-j43 local site 1 remote site 2
>
> admin at boxlabj43> show vpls connections instance ri_j42-j43
> Instance: ri_j42-j43
> Local site: boxlabj43.10002 (2)
> connection-site Type St Time last up # Up trans
> 1 rmt VC-Dn Sep 26 22:13:40 2011 2
> Remote PE: 72.22.160.240, Negotiated control-word: No
> Incoming label: 262145, Outgoing label: 262154
> Local interface: lsi.1138567, Status: Up, Encapsulation: VPLS
> Description: Intf - vpls ri_j42-j43 local site 2 remote site 1
> ***
> admin at boxlabj42> show mpls lsp
> Ingress LSP: 1 sessions
> To From State Rt P ActivePath LSPname
> 72.22.160.241 72.22.160.240 Up 0 * LSP1
> Total 1 displayed, Up 1, Down 0
> Egress LSP: 1 sessions
> To From State Rt Style Labelin Labelout LSPname
> 72.22.160.240 72.22.160.241 Up 0 1 FF 3 - LSP1
> Total 1 displayed, Up 1, Down 0
> Transit LSP: 0 sessions
> Total 0 displayed, Up 0, Down 0
>
> admin at boxlabj43> show mpls lsp
> Ingress LSP: 1 sessions
> To From State Rt P ActivePath LSPname
> 72.22.160.241 72.22.160.205 Up 0 * LSP2
> Total 1 displayed, Up 1, Down 0
> Egress LSP: 1 sessions
> To From State Rt Style Labelin Labelout LSPname
> 72.22.160.205 72.22.160.241 Up 0 1 FF 3 - LSP2
> Total 1 displayed, Up 1, Down 0
> Transit LSP: 2 sessions
> To From State Rt Style Labelin Labelout LSPname
> 72.22.160.240 72.22.160.241 Up 1 1 FF 299824 3 LSP1
> 72.22.160.241 72.22.160.240 Up 1 1 FF 299808 3 LSP1
> Total 2 displayed, Up 2, Down 0
> ****
> admin at boxlabj43> show route
> *snip*
> ri_j42-j43.l2vpn.0: 2 destinations, 2 routes (2 active, 0 holddown, 0
> hidden)
> + = Active Route, - = Last Active, * = Both
> 72.22.160.205:10002:2:1/96
> *[L2VPN/170/-101] 2w2d 02:29:29, metric2 1
> Indirect
> 72.22.160.240:10002:1:1/96
> *[BGP/170] 2d 06:26:01, localpref 100, from 72.22.160.241
> AS path: I
> > to 72.22.160.12 via ge-0/0/9.0
> admin at boxlabj43> show route
> *snip*
> ri_j42-j43.l2vpn.0: 2 destinations, 2 routes (2 active, 0 holddown, 0
> hidden)
> + = Active Route, - = Last Active, * = Both
> 72.22.160.205:10002:2:1/96
> *[L2VPN/170/-101] 2w2d 02:29:29, metric2 1
> Indirect
> 72.22.160.240:10002:1:1/96
> *[BGP/170] 2d 06:26:01, localpref 100, from 72.22.160.241
> AS path: I
> > to 72.22.160.12 via ge-0/0/9.0
> **notice pw trying to establish across IGP \ non LSP path.**
>
> Regards,
> Peter K.
>
>
> On Sep 28, 2011, at 6:00 PM, David Ball wrote:
>
> On 28 September 2011 14:27, Peter K <pjkpub at gmail.com> wrote:
>
> Goal is to deploy label switch routers specifically functioning only as PE
>
> (distribution) nodes with direct connectivity to the P\PE (core) nodes and
>
> avoid the configuration required for a full mesh of LSP’s and l2vpn
>
> signaling between the P\PE core nodes and the PE distribution nodes. Below
>
> is an outline of requirements.
>
> Safe to assume you're running LDP on your LERs as well ?
>
>
> I am noticing the pseudo-wire is attempting to establish a session across a
>
> routed link (with RSVP and MPLS enabled) without a defined LSP path causing
>
> any pseudo-wires using that path to go down. The pseudo-wire
>
> re-establishes its connection when the IGP metric is modified and reroutes
>
> traffic or when then named LSP is created between the two PE nodes.
>
> Although this appears to be an issue regarding order of operations when
>
> deploying a new node(d) in this configuration, is there a mechanism in place
>
> to restrict pseudo-wires from trying to establish connections across a path
>
> without an established LSP path across the connection?
>
> Not sure I follow here. All your L2vpns traversing a given link
> from your LER to the LSR drop when a new one is being signalled? When
> they drop, what is the output of a 'show l2vpn connections' for them ?
>
> David
>
>
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