Hi nagp, It can be added with: ip route add 10.1.1.1 via 10.1.1.1 <INTERFACE> out-label imp-null
It is mandatory whenever there is a labelled recursive that there is also an LSP to the next-hop. For example, given; ip route 1.1.1.1/32 via 10.1.1.1 out-label 44 it is router 10.1.1.1 that has advertised 44 as the label for 1.1.1.1/32, therefore it is ONLY 10.1.1.1 that should see packets with the label 44. If we then have; ip route 10.1.1.1/32 via 192.168.1.1 Eth0 if we allowed that route to be the resolution target for 1.1.1.1/32 then we would send packets with label 44 to 192.168.1.1 which would in turn drop them, or worse mis-forward them, since label 44 means something different. But give the route its own labels; Ip route 10.1.1.1/32 via 192.168.1.1 Eth0 out-label 55 And we now have an LSP to 10.1.1.1, any packet we send via 192.168.1.1 will have 55 as the out label, and we are golden. The same applies when the next-hop is directly attached. There needs to be an LSP to reach the next-hop – since it’s directly attached imp-null is the out-label. Regards, neale From: Nagaprabhanjan Bellari <nagp.li...@gmail.com> Date: Saturday, 10 June 2017 at 03:50 To: "Neale Ranns (nranns)" <nra...@cisco.com> Cc: vpp-dev <vpp-dev@lists.fd.io> Subject: Re: Is this a valid route? I mean, if I have 10.1.1.2/24<http://10.1.1.2/24> configured on an interface, then how can I add another route with an implicit null out label? Thanks, -nagp On Jun 10, 2017 08:10, "Nagaprabhanjan Bellari" <nagp.li...@gmail.com<mailto:nagp.li...@gmail.com>> wrote: Hi Neale, Yes, 10.1.1.1 is a direct attached route, but it does not have the implicit null explicitly configured. Is it mandatory? Thanks, -nagp On Friday, June 9, 2017, Neale Ranns (nranns) <nra...@cisco.com<mailto:nra...@cisco.com>> wrote: Hi nagp, That’s the correct way to do it. Does 10.1.1.1 in table 0 have out-labels? It needs then in order to be a resolution target for a labelled recursive. Implicit-null is the expected out-label if 10.1.1.1 is directly attached. Regards, Neale From: <vpp-dev-boun...@lists.fd.io> on behalf of Nagaprabhanjan Bellari <nagp.li...@gmail.com> Date: Friday, 9 June 2017 at 14:30 To: vpp-dev <vpp-dev@lists.fd.io> Subject: [SUSPICIOUS] [vpp-dev] Is this a valid route? Hi, I am trying to add the following route in VPP, but it is only getting a drop-dpo in "show ip fib": "ip route add table 2 4.4.4.4/32<http://secure-web.cisco.com/13XjmUsXfAcVtsFEheLw8wZ39WD3SNgxlyOe1tfZRwNTnTbkat8sXvJM9NqiNJ7ni8fykpKNE64Y-WCIiGt18MHoHCe6qJJ2zVVOQTwvKzsE5bka2lbn4yWUh_g-DKxcQb37bKeg7LaUht6WWe6PXPxfi3izIvHWmeL-AsAMu_pXDNd3S6Zqp7HeUDC2MIfLzq9Iiit12gTZAcoQQRTrm4WJcovPN8p1Vlydsjl_-cV5v_rlJYp-WqyO9nAeGjiG5LrdDwbLPa5omQ0dgZlDIu2wCTTb9hjsivxpL_q3uhCKWHmQXEdB2eL2S-ODk5zn9/http%3A%2F%2F4.4.4.4%2F32> via 10.1.1.1 next-hop-table 0 out-label 300" I am trying to add 4.4.4.4/32<http://secure-web.cisco.com/13XjmUsXfAcVtsFEheLw8wZ39WD3SNgxlyOe1tfZRwNTnTbkat8sXvJM9NqiNJ7ni8fykpKNE64Y-WCIiGt18MHoHCe6qJJ2zVVOQTwvKzsE5bka2lbn4yWUh_g-DKxcQb37bKeg7LaUht6WWe6PXPxfi3izIvHWmeL-AsAMu_pXDNd3S6Zqp7HeUDC2MIfLzq9Iiit12gTZAcoQQRTrm4WJcovPN8p1Vlydsjl_-cV5v_rlJYp-WqyO9nAeGjiG5LrdDwbLPa5omQ0dgZlDIu2wCTTb9hjsivxpL_q3uhCKWHmQXEdB2eL2S-ODk5zn9/http%3A%2F%2F4.4.4.4%2F32> in table 2 but its nexthop, 10.1.1.1, has to be resolved in table 0 and the packet has to be strapped a label while going out (the typical l3vpn case) Can you please tell me if this is the right way to do so? Thanks, -nagp
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